Modulation of the operational characteristics of amorphous In-Ga-Zn-O thin-film transistors by In2O3 nanoparticles

NASA Astrophysics Data System (ADS)

Lee, Min-Jung; Lee, Tae Il; Park, Jee Ho; Kim, Jung Han; Chae, Gee Sung; Jun, Myung Chul; Hwang, Yong Kee; Baik, Hong Koo; Lee, Woong; Myoung, Jae-Min

2012-05-01

The structure of thin-film transistors (TFTs) based on amorphous In-Ga-Zn-O (a-IGZO) was modified by spin coating a suspension of In2O3 nanoparticles on a SiO2/p++ Si layered wafer surface prior to the deposition of IGZO layer by room-temperature sputtering. The number of particles per unit area (surface density) of the In2O3 nanoparticles could be controlled by applying multiple spin coatings of the nanoparticle suspension. During the deposition of IGZO, the In2O3 nanoparticles initially located on the substrate surface migrated to the top of the IGZO layer indicating that they were not embedded within the IGZO layer, but they supplied In to the IGZO layer to increase the In concentration in the channel layer. As a result, the channel characteristics of the a-IGZO TFT were modulated so that the device showed an enhanced performance as compared with the reference device prepared without the nanoparticle treatment. Such an improved device performance is attributed to the nano-scale changes in the structure of (InO)n ordering assisted by increased In concentration in the amorphous channel layer.

Effects of Gold Nanoparticles on Pentacene Organic Field-Effect Transistors

NASA Astrophysics Data System (ADS)

Lee, Keanchuan; Weis, Martin; Ou-Yang, Wei; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

2011-04-01

The effect of gold nanoparticles (NPs) on pentacene organic field-effect transistors (OFETs) was being investigated by both DC and AC methods, which are current-voltage (I-V) measurements in steady-state and impedance spectroscopy (IS) respectively. Here poly(vinyl alcohol) (PVA) and PVA blended with Au NPs as composite are spin-coated on SiO2 as gate-insulator for top-contact pentacene OFET. The characteristics of the device were being investigated based on the contact resistance, trapped charges, effective mobility and threshold voltage based on transfer characteristics of OFET. Results revealed that OFET with NPs exhibited larger hysteresis and higher contact resistance at high voltage region. IS measurements were performed and the fitting of results by the Maxwell-Wagner equivalent circuit showed that for device with NPs a series of capacitance and resistance which represents trapping must be introduced in order to have agreeable fitting. The fitting had helped to clarify the reason behind the higher contact resistance and bigger hysteresis which was mainly caused by the space charge field formed by the traps when Au NPs were introduced into the device.

Trapping effect of metal nanoparticle mono- and multilayer in the organic field-effect transistor

NASA Astrophysics Data System (ADS)

Lee, Keanchuan; Weis, Martin; Lin, Jack; Taguchi, Dai; Majková, Eva; Manaka, Takaaki; Iwamoto, Mitsumasa

2011-03-01

The effect of silver nanoparticles self-assembled monolayer (Ag NPs SAM) on charge transport in pentacene organic field-effect transistors (OFET) was investigated by both steady-state and transient-state methods, which are current-voltage measurements in steady-state and time-resolved microscopic (TRM) second harmonic generation (SHG) in transient-state, respectively. The analysis of electronic properties revealed that OFET with SAM exhibited significant charge trapping effect due to the space-charge field formed by immobile charges. Lower transient-state mobility was verified by the direct probing of carrier motion by TRM-SHG technique. It was shown that the trapping effect rises together with increase of SAM layers suggesting the presence of traps in the bulk of NP films. The model based on the electrostatic charge barrier is suggested to explain the phenomenon.

Do you BEHAVE? - Application of the BehavePlus fire modeling system

Treesearch

Pat Andrews

2010-01-01

The BehavePlus fire modeling system is the successor to BEHAVE, which was first used in the field in 1984. It is public domain software, available for free use on personal computers. Information on user communities and fire management applications can be useful in designing next generation systems. Several sources of information about BehavePlus are summarized to...

Highly stable precursor solution containing ZnO nanoparticles for the preparation of ZnO thin film transistors.

PubMed

Huang, Heh-Chang; Hsieh, Tsung-Eong

2010-07-23

ZnO particles with an average size of about 5 nm were prepared via a sol-gel chemical route and the silane coupling agent, (3-glycidyloxypropyl)-trimethoxysilane (GPTS), was adopted to enhance the dispersion of the ZnO nanoparticles in ethyl glycol (EG) solution. A ZnO surface potential as high as 66 mV was observed and a sedimentation test showed that the ZnO precursor solution remains transparent for six months of storage, elucidating the success of surface modification on ZnO nanoparticles. The ZnO thin films were then prepared by spin coating the precursor solution on a Si wafer and annealing treatments at temperatures up to 500 degrees C were performed for subsequent preparation of ZnO thin film transistors (TFTs). Microstructure characterization revealed that the coalescence of ZnO nanoparticles occurs at temperatures as low as 200 degrees C to result in a highly uniform, nearly pore-free layer. However, annealing at higher temperatures was required to remove organic residues in the ZnO layer for satisfactory device performance. The 500 degrees C-annealed ZnO TFT sample exhibited the best electrical properties with on/off ratio = 10(5), threshold voltage = 17.1 V and mobility (micro) = 0.104 cm(2) V(-1) s(-1).

Random telegraph signals by alkanethiol-protected Au nanoparticles in chemically assembled single-electron transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kano, Shinya; CREST, Japan Science and Technology Agency, Yokohama 226-8503; Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE

2013-12-14

We have studied random telegraph signals (RTSs) in a chemically assembled single-electron transistor (SET) at temperatures as low as 300 mK. The RTSs in the chemically assembled SET were investigated by measuring the source–drain current, using a histogram of the RTS dwell time, and calculating the power spectrum density of the drain current–time characteristics. It was found that the dwell time of the RTS was dependent on the drain voltage of the SET, but was independent of the gate voltage. Considering the spatial structure of the chemically assembled SET, the origin of the RTS is attributed to the trapped chargesmore » on an alkanethiol-protected Au nanoparticle positioned near the SET. These results are important as they will help to realize stable chemically assembled SETs in practical applications.« less

Rhombic Coulomb diamonds in a single-electron transistor based on an Au nanoparticle chemically anchored at both ends.

PubMed

Azuma, Yasuo; Onuma, Yuto; Sakamoto, Masanori; Teranishi, Toshiharu; Majima, Yutaka

2016-02-28

Rhombic Coulomb diamonds are clearly observed in a chemically anchored Au nanoparticle single-electron transistor. The stability diagrams show stable Coulomb blockade phenomena and agree with the theoretical curve calculated using the orthodox model. The resistances and capacitances of the double-barrier tunneling junctions between the source electrode and the Au core (R1 and C1, respectively), and those between the Au core and the drain electrode (R2 and C2, respectively), are evaluated as 4.5 MΩ, 1.4 aF, 4.8 MΩ, and 1.3 aF, respectively. This is determined by fitting the theoretical curve against the experimental Coulomb staircases. Two-methylene-group short octanedithiols (C8S2) in a C8S2/hexanethiol (C6S) mixed self-assembled monolayer is concluded to chemically anchor the core of the Au nanoparticle at both ends between the electroless-Au-plated nanogap electrodes even when the Au nanoparticle is protected by decanethiol (C10S). This is because the R1 value is identical to that of R2 and corresponds to the tunneling resistances of the octanedithiol chemically bonded with the Au core and the Au electrodes. The dependence of the Coulomb diamond shapes on the tunneling resistance ratio (R1/R2) is also discussed, especially in the case of the rhombic Coulomb diamonds. Rhombic Coulomb diamonds result from chemical anchoring of the core of the Au nanoparticle at both ends between the electroless-Au-plated nanogap electrodes.

Solution-processed zinc oxide nanoparticles/single-walled carbon nanotubes hybrid thin-film transistors

NASA Astrophysics Data System (ADS)

Liu, Fangmei; Sun, Jia; Qian, Chuan; Hu, Xiaotao; Wu, Han; Huang, Yulan; Yang, Junliang

2016-09-01

Solution-processed thin-film transistors (TFTs) are the essential building blocks for manufacturing the low-cost and large-area consumptive electronics. Herein, solution-processed TFTs based on the composites of zinc oxide (ZnO) nanoparticles and single-walled carbon nanotubes (SWCNTs) were fabricated by the methods of spin-coating and doctor-blading. Through controlling the weight of SWCNTs, the ZnO/SWCNTs TFTs fabricated by spin-coating demonstrated a field-effect mobility of 4.7 cm2/Vs and a low threshold voltage of 0.8 V, while the TFTs devices fabricated by doctor-blading technique showed reasonable electrical performance with a mobility of 0.22 cm2/Vs. Furthermore, the ion-gel was used as an efficient electrochemical gate dielectric because of its large electric double-layer capacitance. The operating voltage of all the TFTs devices is as low as 4.0 V. The research suggests that ZnO/SWCNTs TFTs have the potential applications in low-cost, large-area and flexible consumptive electronics, such as chemical-biological sensors and smart label.

Graphene-based field-effect transistor biosensors

DOEpatents

Chen; , Junhong; Mao, Shun; Lu, Ganhua

2017-06-14

The disclosure provides a field-effect transistor (FET)-based biosensor and uses thereof. In particular, to FET-based biosensors using thermally reduced graphene-based sheets as a conducting channel decorated with nanoparticle-biomolecule conjugates. The present disclosure also relates to FET-based biosensors using metal nitride/graphene hybrid sheets. The disclosure provides a method for detecting a target biomolecule in a sample using the FET-based biosensor described herein.

Tunable conduction type of solution-processed germanium nanoparticle based field effect transistors and their inverter integration.

PubMed

Meric, Zeynep; Mehringer, Christian; Karpstein, Nicolas; Jank, Michael P M; Peukert, Wolfgang; Frey, Lothar

2015-09-14

In this work we demonstrate the fabrication of germanium nanoparticle (NP) based electronics. The whole process chain from the nanoparticle production up to the point of inverter integration is covered. Ge NPs with a mean diameter of 33 nm and a geometric standard deviation of 1.19 are synthesized in the gas phase by thermal decomposition of GeH4 precursor in a seeded growth process. Dispersions of these particles in ethanol are employed to fabricate thin particulate films (60 to 120 nm in thickness) on substrates with a pre-patterned interdigitated aluminum electrode structure. The effect of temperature treatment, polymethyl methacrylate encapsulation and alumina coating by plasma-assisted atomic layer deposition (employing various temperatures) on the performance of these layers as thin film transistors (TFTs) is investigated. This coating combined with thermal annealing delivers ambipolar TFTs which show an Ion/Ioff ratio in the range of 10(2). We report fabrication of n-type, p-type or ambipolar Ge NP TFTs at maximum temperatures of 450 °C. For the first time, a circuit using two ambipolar TFTs is demonstrated to function as a NOT gate with an inverter gain of up to 4 which can be operated at room temperature in ambient air.

Electrical properties of solution-deposited ZnO thin-film transistors by low-temperature annealing.

PubMed

Lim, Chul; Oh, Ji Young; Koo, Jae Bon; Park, Chan Woo; Jung, Soon-Won; Na, Bock Soon; Chu, Hye Yong

2014-11-01

Flexible oxide thin-film transistors (Oxide-TFTs) have emerged as next generation transistors because of their applicability in electronic device. In particular, the major driving force behind solution-processed zinc oxide film research is its prospective use in printing for electronics. A low-temperature process to improve the performance of solution-processed n-channel ZnO thin-film transistors (TFTs) fabricated via spin-coating and inkjet-printing is introduced here. ZnO nanoparticles were synthesized using a facile sonochemical method that was slightly modified based on a previously reported method. The influence of the annealing atmosphere on both nanoparticle-based TFT devices fabricated via spin-coating and those created via inkjet printing was investigated. For the inkjet-printed TFTs, the characteristics were improved significantly at an annealing temperature of 150 degrees C. The field effect mobility, V(th), and the on/off current ratios were 3.03 cm2/Vs, -3.3 V, and 10(4), respectively. These results indicate that annealing at 150 degrees C 1 h is sufficient to obtain a mobility (μ(sat)) as high as 3.03 cm2/Vs. Also, the active layer of the solution-based ZnO nanoparticles allowed the production of high-performance TFTs for low-cost, large-area electronics and flexible devices.

I-V Characteristics of a Static Random Access Memory Cell Utilizing Ferroelectric Transistors

NASA Technical Reports Server (NTRS)

Laws, Crystal; Mitchell, Cody; Hunt, Mitchell; Ho, Fat D.; MacLeod, Todd C.

2012-01-01

I-V characteristics for FeFET different than that of MOSFET Ferroelectric layer features hysteresis trend whereas MOSFET behaves same for both increasing and decreasing VGS FeFET I-V characteristics doesn't show dependence on VDS A Transistor with different channel length and width as well as various resistance and input voltages give different results As resistance values increased, the magnitude of the drain current decreased.

Removing the current-limit of vertical organic field effect transistors

NASA Astrophysics Data System (ADS)

Sheleg, Gil; Greenman, Michael; Lussem, Bjorn; Tessler, Nir

2017-11-01

The reported Vertical Organic Field Effect Transistors (VOFETs) show either superior current and switching speeds or well-behaved transistor performance, especially saturation in the output characteristics. Through the study of the relationship between the device architecture or dimensions and the device performance, we find that achieving a saturation regime in the output characteristics requires that the device operates in the injection limited regime. In current structures, the existence of the injection limited regime depends on the source's injection barrier as well as on the buried semiconductor layer thickness. To overcome the injection limit imposed by the necessity of injection barrier, we suggest a new architecture to realize VOFETs. This architecture shows better gate control and is independent of the injection barrier at the source, thus allowing for several A cm-2 for a semiconductor having a mobility value of 0.1 cm2 V-1 s-1.

Vertical resonant tunneling transistors with molecular quantum dots for large-scale integration.

PubMed

Hayakawa, Ryoma; Chikyow, Toyohiro; Wakayama, Yutaka

2017-08-10

Quantum molecular devices have a potential for the construction of new data processing architectures that cannot be achieved using current complementary metal-oxide-semiconductor (CMOS) technology. The relevant basic quantum transport properties have been examined by specific methods such as scanning probe and break-junction techniques. However, these methodologies are not compatible with current CMOS applications, and the development of practical molecular devices remains a persistent challenge. Here, we demonstrate a new vertical resonant tunneling transistor for large-scale integration. The transistor channel is comprised of a MOS structure with C 60 molecules as quantum dots, and the structure behaves like a double tunnel junction. Notably, the transistors enabled the observation of stepwise drain currents, which originated from resonant tunneling via the discrete molecular orbitals. Applying side-gate voltages produced depletion layers in Si substrates, to achieve effective modulation of the drain currents and obvious peak shifts in the differential conductance curves. Our device configuration thus provides a promising means of integrating molecular functions into future CMOS applications.

Transistor Effect in Improperly Connected Transistors.

ERIC Educational Resources Information Center

Luzader, Stephen; Sanchez-Velasco, Eduardo

1996-01-01

Discusses the differences between the standard representation and a realistic representation of a transistor. Presents an experiment that helps clarify the explanation of the transistor effect and shows why transistors should be connected properly. (JRH)

Intrinsically stretchable and transparent thin-film transistors based on printable silver nanowires, carbon nanotubes and an elastomeric dielectric

PubMed Central

Liang, Jiajie; Li, Lu; Chen, Dustin; Hajagos, Tibor; Ren, Zhi; Chou, Shu-Yu; Hu, Wei; Pei, Qibing

2015-01-01

Thin-film field-effect transistor is a fundamental component behind various mordern electronics. The development of stretchable electronics poses fundamental challenges in developing new electronic materials for stretchable thin-film transistors that are mechanically compliant and solution processable. Here we report the fabrication of transparent thin-film transistors that behave like an elastomer film. The entire fabrication is carried out by solution-based techniques, and the resulting devices exhibit a mobility of ∼30 cm2 V−1 s−1, on/off ratio of 103–104, switching current >100 μA, transconductance >50 μS and relative low operating voltages. The devices can be stretched by up to 50% strain and subjected to 500 cycles of repeated stretching to 20% strain without significant loss in electrical property. The thin-film transistors are also used to drive organic light-emitting diodes. The approach and results represent an important progress toward the development of stretchable active-matrix displays. PMID:26173436

Effect of atomic layer deposition temperature on the performance of top-down ZnO nanowire transistors

PubMed Central

2014-01-01

This paper studies the effect of atomic layer deposition (ALD) temperature on the performance of top-down ZnO nanowire transistors. Electrical characteristics are presented for 10-μm ZnO nanowire field-effect transistors (FETs) and for deposition temperatures in the range 120°C to 210°C. Well-behaved transistor output characteristics are obtained for all deposition temperatures. It is shown that the maximum field-effect mobility occurs for an ALD temperature of 190°C. This maximum field-effect mobility corresponds with a maximum Hall effect bulk mobility and with a ZnO film that is stoichiometric. The optimized transistors have a field-effect mobility of 10 cm2/V.s, which is approximately ten times higher than can typically be achieved in thin-film amorphous silicon transistors. Furthermore, simulations indicate that the drain current and field-effect mobility extraction are limited by the contact resistance. When the effects of contact resistance are de-embedded, a field-effect mobility of 129 cm2/V.s is obtained. This excellent result demonstrates the promise of top-down ZnO nanowire technology for a wide variety of applications such as high-performance thin-film electronics, flexible electronics, and biosensing. PMID:25276107

Photoresponse and photo-induced memory effect in the organic field-effect transistor based on AlOX nanoparticles at the interface of semiconductor/dielectric

NASA Astrophysics Data System (ADS)

Cheng, Yunfei; Wang, Wu

2017-10-01

In this work, the photoresponse and photo-induced memory effect were demonstrated in an organic field-effect transistor (OFET) with semiconductor pentacene and SiO2 as the active and gate dielectric layers, respectively. By inserting AlOX nanoparticles (NPs) at the interface of pentacene/SiO2, obvious enhancing photoresponse was obtained in the OFET with the maximum responsivity and photosensitivity of about 15 A/W and 100, respectively. Moreover, the stable photoinduced memory effect was achieved in the OFET, attributing to the photogenerated electrons captured by the interface traps of the AlOX NPs/SiO2.

Organic electrochemical transistor based immunosensor for prostate specific antigen (PSA) detection using gold nanoparticles for signal amplification.

PubMed

Kim, Duck-Jin; Lee, Nae-Eung; Park, Joon-Shik; Park, In-Jun; Kim, Jung-Gu; Cho, Hyoung J

2010-07-15

We demonstrated a highly sensitive organic electrochemical transistor (OECT) based immunosensor with a low detection limit for prostate specific antigen/alpha1-antichymotrypsin (PSA-ACT) complex. The poly(styrenesulfonate) doped poly(3,4-ethylenedioxythiophene) (PEDOT:PSS) based OECT with secondary antibody conjugated gold nanoparticles (AuNPs) provided a detection limit of the PSA-ACT complex as low as 1pg/ml, as well as improved sensitivity and a dynamic range, due to the role of AuNPs in the signal amplification. The sensor performances were particularly improved in the lower concentration range where the detection is clinically important for the preoperative diagnosis and screening of prostate cancer. This result shows that the OECT-based immunosensor can be used as a transducer platform acceptable to the point-of-care (POC) diagnostic systems and demonstrates adaptability of organic electronics to clinical applications. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Protein Viability on Au Nanoparticles during an Electrospray and Electrostatic-Force-Directed Assembly Process

DOE PAGES

Mao, Shun; Lu, Ganhua; Yu, Kehan; ...

2010-01-01

We study the protein viability on Au nanoparticles during an electrospray and electrostatic-force-directed assembly process, through which Au nanoparticle-antibody conjugates are assembled onto the surface of carbon nanotubes (CNTs) to fabricate carbon nanotube field-effect transistor (CNTFET) biosensors. Enzyme-linked immunosorbent assay (ELISA) and field-effect transistor (FET) measurements have been used to investigate the antibody activity after the nanoparticle assembly. Upon the introduction of matching antigens, the colored reaction from the ELISA and the change in the electrical characteristic of the CNTFET device confirm that the antibody activity is preserved during the assembly process.

Sub-parts per million NO2 chemi-transistor sensors based on composite porous silicon/gold nanostructures prepared by metal-assisted etching.

PubMed

Sainato, Michela; Strambini, Lucanos Marsilio; Rella, Simona; Mazzotta, Elisabetta; Barillaro, Giuseppe

2015-04-08

Surface doping of nano/mesostructured materials with metal nanoparticles to promote and optimize chemi-transistor sensing performance represents the most advanced research trend in the field of solid-state chemical sensing. In spite of the promising results emerging from metal-doping of a number of nanostructured semiconductors, its applicability to silicon-based chemi-transistor sensors has been hindered so far by the difficulties in integrating the composite metal-silicon nanostructures using the complementary metal-oxide-semiconductor (CMOS) technology. Here we propose a facile and effective top-down method for the high-yield fabrication of chemi-transistor sensors making use of composite porous silicon/gold nanostructures (cSiAuNs) acting as sensing gate. In particular, we investigate the integration of cSiAuNs synthesized by metal-assisted etching (MAE), using gold nanoparticles (NPs) as catalyst, in solid-state junction-field-effect transistors (JFETs), aimed at the detection of NO2 down to 100 parts per billion (ppb). The chemi-transistor sensors, namely cSiAuJFETs, are CMOS compatible, operate at room temperature, and are reliable, sensitive, and fully recoverable for the detection of NO2 at concentrations between 100 and 500 ppb, up to 48 h of continuous operation.

Characterization of Screen-Printed Organic Electrochemical Transistors to Detect Cations of Different Sizes.

PubMed

Contat-Rodrigo, Laura; Pérez-Fuster, Clara; Lidón-Roger, José Vicente; Bonfiglio, Annalisa; García-Breijo, Eduardo

2016-09-28

A novel screen-printing fabrication method was used to prepare organic electrochemical transistors (OECTs) based on poly(3,4-ethylenedioxythiophene) doped with polysterene sulfonate (PEDOT:PSS). Initially, three types of these screen-printed OECTs with a different channel and gate areas ratio were compared in terms of output characteristics, transfer characteristics, and current modulation in a phosphate buffered saline (PBS) solution. Results confirm that transistors with a gate electrode larger than the channel exhibit higher modulation. OECTs with this geometry were therefore chosen to investigate their ion-sensitive properties in aqueous solutions of cations of different sizes (sodium and rhodamine B). The effect of the gate electrode was additionally studied by comparing these all-PEDOT:PSS transistors with OECTs with the same geometry but with a non-polarizable metal gate (Ag). The operation of the all-PEDOT:PSS OECTs yields a response that is not dependent on a Na⁺ or rhodamine concentration. The weak modulation of these transistors can be explained assuming that PEDOT:PSS behaves like a supercapacitor. In contrast, the operation of Ag-Gate OECTs yields a response that is dependent on ion concentration due to the redox reaction taking place at the gate electrode with Cl - counter-ions. This indicates that, for cation detection, the response is maximized in OECTs with non-polarizable gate electrodes.

Inkjet printed graphene-based field-effect transistors on flexible substrate

NASA Astrophysics Data System (ADS)

Monne, Mahmuda Akter; Enuka, Evarestus; Wang, Zhuo; Chen, Maggie Yihong

2017-08-01

This paper presents the design and fabrication of inkjet printed graphene field-effect transistors (GFETs). The inkjet printed GFET is fabricated on a DuPont Kapton FPC Polyimide film with a thickness of 5 mill and dielectric constant of 3.9 by using a Fujifilm Dimatix DMP-2831 materials deposition system. A layer by layer 3D printing technique is deployed with an initial printing of source and drain by silver nanoparticle ink. Then graphene active layer doped with molybdenum disulfide (MoS2) monolayer/multilayer dispersion, is printed onto the surface of substrate covering the source and drain electrodes. High capacitance ion gel is adopted as the dielectric material due to the high dielectric constant. Then the dielectric layer is then covered with silver nanoparticle gate electrode. Characterization of GFET has been done at room temperature (25°C) using HP-4145B semiconductor parameter analyzer (Hewlett-Packard). The characterization result shows for a voltage sweep from -2 volts to 2 volts, the drain current changes from 949 nA to 32.3 μA and the GFET achieved an on/off ratio of 38:1, which is a milestone for inkjet printed flexible graphene transistor.

Nanocomposites of polyimide and mixed oxide nanoparticles for high performance nanohybrid gate dielectrics in flexible thin film transistors

NASA Astrophysics Data System (ADS)

Kim, Ju Hyun; Hwang, Byeong-Ung; Kim, Do-Il; Kim, Jin Soo; Seol, Young Gug; Kim, Tae Woong; Lee, Nae-Eung

2017-05-01

Organic gate dielectrics in thin film transistors (TFTs) for flexible display have advantages of high flexibility yet have the disadvantage of low dielectric constant (low- k). To supplement low- k characteristics of organic gate dielectrics, an organic/inorganic nanocomposite insulator loaded with high- k inorganic oxide nanoparticles (NPs) has been investigated but high loading of high- k NPs in polymer matrix is essential. Herein, compositing of over-coated polyimide (PI) on self-assembled (SA) layer of mixed HfO2 and ZrO2 NPs as inorganic fillers was used to make dielectric constant higher and leakage characteristics lower. A flexible TFT with lower the threshold voltage and high current on/off ratio could be fabricated by using the hybrid gate dielectric structure of the nanocomposite with SA layer of mixed NPs on ultrathin atomic-layer deposited Al2O3. [Figure not available: see fulltext.

Development of paper-gate transistor toward direct detection from microbiological fluids

NASA Astrophysics Data System (ADS)

Kajisa, Taira; Sakata, Toshiya

2017-04-01

In this study, a paper-gate transistor was developed to detect glucose using an extended-gate field-effect transistor (FET). A filter paper was used as an extended gate electrode, in which Au nanoparticles (AuNPs) modified with phenylboronic acids (PBAs) were included. PBA-AuNPs play an important role as a support to not only be entrapped in cellulose fibrils but also bind to the targeted glucose in a paper. The surface properties of PBA-AuNPs were investigated to elucidate the electrical properties of the paper-gate electrode using an absorption spectrum and a zeta potential analysis. Moreover, the paper-gate electrode enabled us to detect glucose at the micromolar level on the basis of the principle of FET devices. A platform based on the paper-gate transistor is suitable for a highly sensitive system to detect glucose in trace samples such as tears, sweat, and saliva in the future.

STABILIZED TRANSISTOR AMPLIFIER

DOEpatents

Noe, J.B.

1963-05-01

A temperature stabilized transistor amplifier having a pair of transistors coupled in cascade relation that are capable of providing amplification through a temperature range of - 100 un. Concent 85% F to 400 un. Concent 85% F described. The stabilization of the amplifier is attained by coupling a feedback signal taken from the emitter of second transistor at a junction between two serially arranged biasing resistances in the circuit of the emitter of the second transistor to the base of the first transistor. Thus, a change in the emitter current of the second transistor is automatically corrected by the feedback adjustment of the base-emitter potential of the first transistor and by a corresponding change in the base-emitter potential of the second transistor. (AEC)

Probing the Quantum States of a Single Atom Transistor at Microwave Frequencies.

PubMed

Tettamanzi, Giuseppe Carlo; Hile, Samuel James; House, Matthew Gregory; Fuechsle, Martin; Rogge, Sven; Simmons, Michelle Y

2017-03-28

The ability to apply gigahertz frequencies to control the quantum state of a single P atom is an essential requirement for the fast gate pulsing needed for qubit control in donor-based silicon quantum computation. Here, we demonstrate this with nanosecond accuracy in an all epitaxial single atom transistor by applying excitation signals at frequencies up to ≈13 GHz to heavily phosphorus-doped silicon leads. These measurements allow the differentiation between the excited states of the single atom and the density of states in the one-dimensional leads. Our pulse spectroscopy experiments confirm the presence of an excited state at an energy ≈9 meV, consistent with the first excited state of a single P donor in silicon. The relaxation rate of this first excited state to the ground state is estimated to be larger than 2.5 GHz, consistent with theoretical predictions. These results represent a systematic investigation of how an atomically precise single atom transistor device behaves under radio frequency excitations.

Pupils' reasons for learning and behaving and for not learning and behaving in English and maths lessons in a secondary school.

PubMed

Norwich, B

1999-12-01

There is renewed interest in motivation and school learning, though there has been relatively little theory-linked research in English schools. In the first stage, to explore pupils' reasons for learning and behaving and for not learning and behaving in English, maths and other subjects. In the second stage, to examine differences in reasons across subjects, for learning and behaving and for not learning and behaving for boys and girls in two year groups in one secondary school. Stage 1, 16 pupils in years 7, 8 and 9 in two London secondary schools; Stage 2, 267 pupils in years 7 and 9 in one of these schools. Stage 1--semi-structured interviews were conducted to elicit different kinds of reasons conceptualised in terms of the Deci & Ryan's (1985) framework of self-determination. From these elicited reasons, an inventory 'Why I Learn' was designed. Stage 2--the inventory was administered to identify reasons for learning and behaving and for not learning and behaving in English and maths. Parent introjected reasons were the highest for learning and behaving while teacher introjected and intrinsic reasons were the lowest. Intrinsic reasons were highest for not learning and behaving. Year group differences in reason levels were more significant than gender or subject differences. Reasons for learning and behaving were more differentiated from each other than reasons for not learning and behaving. The results are discussed in terms of their significance for self-determination theory, research into the conditions promoting greater self-determination in school learning and further development of the inventory for programme evaluation.

Engineering of Metal Oxide Nanoparticles for Application in Electrochemical Devices

NASA Astrophysics Data System (ADS)

Santos, Lidia Sofia Leitao

The growing demand for materials and devices with new functionalities led to the increased interest in the field of nanomaterials and nanotechnologies. Nanoparticles, not only present a reduced size as well as high reactivity, which allows the development of electronic and electrochemical devices with exclusive properties, when compared with thin films. This dissertation aims to explore the development of several nanostructured metal oxides by solvothermal synthesis and its application in different electrochemical devices. Within this broad theme, this study has a specific number of objectives: a) research of the influence of the synthesis parameters to the structure and morphology of the nanoparticles; b) improvement of the performance of the electrochromic devices with the application of the nanoparticles as electrode; c) application of the nanoparticles as probes to sensing devices; and d) production of solution-pro-cessed transistors with a nanostructured metal oxide semiconductor. Regarding the results, several conclusions can be exposed. Solvothermal synthesis shows to be a very versatile method to control the growth and morphology of the nanoparticles. The electrochromic device performance is influenced by the different structures and morphologies of WO3 nanoparticles, mainly due to the surface area and conductivity of the materials. The deposition of the electrochromic layer by inkjet printing allows the patterning of the electrodes without wasting material and without any additional steps. Nanostructured WO3 probes were produced by electrodeposition and drop casting and applied as pH sensor and biosensor, respectively. The good performance and sensitivity of the devices is explained by the high number of electrochemical reactions occurring at the surface of the na-noparticles. GIZO nanoparticles were deposited by spin coating and used in electrolyte-gated transistors, which promotes a good interface between the semiconductor and the dielectric. The

Doped Organic Transistors.

PubMed

Lüssem, Björn; Keum, Chang-Min; Kasemann, Daniel; Naab, Ben; Bao, Zhenan; Leo, Karl

2016-11-23

Organic field-effect transistors hold the promise of enabling low-cost and flexible electronics. Following its success in organic optoelectronics, the organic doping technology is also used increasingly in organic field-effect transistors. Doping not only increases device performance, but it also provides a way to fine-control the transistor behavior, to develop new transistor concepts, and even improve the stability of organic transistors. This Review summarizes the latest progress made in the understanding of the doping technology and its application to organic transistors. It presents the most successful doping models and an overview of the wide variety of materials used as dopants. Further, the influence of doping on charge transport in the most relevant polycrystalline organic semiconductors is reviewed, and a concise overview on the influence of doping on transistor behavior and performance is given. In particular, recent progress in the understanding of contact doping and channel doping is summarized.

Position-dependent performance of copper phthalocyanine based field-effect transistors by gold nanoparticles modification.

PubMed

Luo, Xiao; Li, Yao; Lv, Wenli; Zhao, Feiyu; Sun, Lei; Peng, Yingquan; Wen, Zhanwei; Zhong, Junkang; Zhang, Jianping

2015-01-21

A facile fabrication and characteristics of copper phthalocyanine (CuPc)-based organic field-effect transistor (OFET) using the gold nanoparticles (Au NPs) modification is reported, thereby achieving highly improved performance. The effect of Au NPs located at three different positions, that is, at the SiO2/CuPc interface (device B), embedding in the middle of CuPc layer (device C), and on the top of CuPc layer (device D), is investigated, and the results show that device D has the best performance. Compared with the device without Au NPs (reference device A), device D displays an improvement of field-effect mobility (μ(sat)) from 1.65 × 10(-3) to 5.51 × 10(-3) cm(2) V(-1) s(-1), and threshold voltage decreases from -23.24 to -16.12 V. Therefore, a strategy for the performance improvement of the CuPc-based OFET with large field-effect mobility and saturation drain current is developed, on the basis of the concept of nanoscale Au modification. The model of an additional electron transport channel formation by FET operation at the Au NPs/CuPc interface is therefore proposed to explain the observed performance improvement. Optimum CuPc thickness is confirmed to be about 50 nm in the present study. The device-to-device uniformity and time stability are discussed for future application.

Mobility Enhancement in Amorphous In-Ga-Zn-O Thin-Film Transistor by Induced Metallic in Nanoparticles and Cu Electrodes.

PubMed

Hu, Shiben; Ning, Honglong; Lu, Kuankuan; Fang, Zhiqiang; Li, Yuzhi; Yao, Rihui; Xu, Miao; Wang, Lei; Peng, Junbiao; Lu, Xubing

2018-03-27

In this work, we fabricated a high-mobility amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistor (TFT) based on alumina oxide (Al 2 O 3 ) passivation layer (PVL) and copper (Cu) source/drain electrodes (S/D). The mechanism of the high mobility for a-IGZO TFT was proposed and experimentally demonstrated. The conductivity of the channel layer was significantly improved due to the formation of metallic In nanoparticles on the back channel during Al 2 O 3 PVL sputtering. In addition, Ar atmosphere annealing induced the Schottky contact formation between the Cu S/D and the channel layer caused by Cu diffusion. In conjunction with high conductivity channel and Schottky contact, the a-IGZO TFT based on Cu S/D and Al 2 O 3 PVL exhibited remarkable mobility of 33.5-220.1 cm 2 /Vs when channel length varies from 60 to 560 μ m. This work presents a feasible way to implement high mobility and Cu electrodes in a-IGZO TFT, simultaneously.

Alumina nanoparticle/polymer nanocomposite dielectric for flexible amorphous indium-gallium-zinc oxide thin film transistors on plastic substrate with superior stability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lai, Hsin-Cheng; Pei, Zingway, E-mail: zingway@dragon.nchu.edu.tw; Graduate Institute of Optoelectronic Engineering, National Chung Hsing University, Taichung 40227, Taiwan

In this study, the Al{sub 2}O{sub 3} nanoparticles were incorporated into polymer as a nono-composite dielectric for used in a flexible amorphous Indium-Gallium-Zinc Oxide (a-IGZO) thin-film transistor (TFT) on a polyethylene naphthalate substrate by solution process. The process temperature was well below 100 °C. The a-IGZO TFT exhibit a mobility of 5.13 cm{sup 2}/V s on the flexible substrate. After bending at a radius of 4 mm (strain = 1.56%) for more than 100 times, the performance of this a-IGZO TFT was nearly unchanged. In addition, the electrical characteristics are less altered after positive gate bias stress at 10 V for 1500 s. Thus, this technology ismore » suitable for use in flexible displays.« less

Kinase detection with gallium nitride based high electron mobility transistors

PubMed Central

Makowski, Matthew S.; Bryan, Isaac; Sitar, Zlatko; Arellano, Consuelo; Xie, Jinqiao; Collazo, Ramon; Ivanisevic, Albena

2013-01-01

A label-free kinase detection system was fabricated by the adsorption of gold nanoparticles functionalized with kinase inhibitor onto AlGaN/GaN high electron mobility transistors (HEMTs). The HEMTs were operated near threshold voltage due to the greatest sensitivity in this operational region. The Au NP/HEMT biosensor system electrically detected 1 pM SRC kinase in ionic solutions. These results are pertinent to drug development applications associated with kinase sensing. PMID:23918992

EDITORIAL: Reigniting innovation in the transistor Reigniting innovation in the transistor

NASA Astrophysics Data System (ADS)

Demming, Anna

2012-09-01

Today the transistor is integral to the electronic circuitry that wires our lives. When Bardeen and Brattain first observed an amplified signal by connecting electrodes to a germanium crystal they saw that their 'semiconductor triode' could prove a useful alternative to the more cumbersome vacuum tubes used at the time [1]. But it was perhaps William Schottky who recognized the extent of the transistor's potential. A basic transistor has three or more terminals and current across one pair of terminals can switch or amplify current through another pair. Bardeen, Brattain and Schottky were jointly awarded a Nobel Prize in 1956 'for their researches on semiconductors and their discovery of the transistor effect' [2]. Since then many new forms of the transistor have been developed and understanding of the underlying properties is constantly advancing. In this issue Chen and Shih and colleagues at Taiwan National University and Drexel University report a pyroelectrics transistor. They show how a novel optothermal gating mechanism can modulate the current, allowing a range of developments in nanoscale optoelectronics and wireless devices [3]. The explosion of interest in nanoscale devices in the 1990s inspired electronics researchers to look for new systems that can act as transistors, such as carbon nanotube [4] and silicon nanowire [5] transistors. Generally these transistors function by raising and lowering an energy barrier of kBT -1, but researchers in the US and Canada have demonstrated that the quantum interference between two electronic pathways through aromatic molecules can also modulate the current flow [6]. The device has advantages for further miniaturization where energy dissipation in conventional systems may eventually cause complications. Interest in transistor technology has also led to advances in fabrication techniques for achieving high production quantities, such as printing [7]. Researchers in Florida in the US demonstrated field effect transistor

Highly Conductive Graphene/Ag Hybrid Fibers for Flexible Fiber-Type Transistors.

PubMed

Yoon, Sang Su; Lee, Kang Eun; Cha, Hwa-Jin; Seong, Dong Gi; Um, Moon-Kwang; Byun, Joon-Hyung; Oh, Youngseok; Oh, Joon Hak; Lee, Wonoh; Lee, Jea Uk

2015-11-09

Mechanically robust, flexible, and electrically conductive textiles are highly suitable for use in wearable electronic applications. In this study, highly conductive and flexible graphene/Ag hybrid fibers were prepared and used as electrodes for planar and fiber-type transistors. The graphene/Ag hybrid fibers were fabricated by the wet-spinning/drawing of giant graphene oxide and subsequent functionalization with Ag nanoparticles. The graphene/Ag hybrid fibers exhibited record-high electrical conductivity of up to 15,800 S cm(-1). As the graphene/Ag hybrid fibers can be easily cut and placed onto flexible substrates by simply gluing or stitching, ion gel-gated planar transistors were fabricated by using the hybrid fibers as source, drain, and gate electrodes. Finally, fiber-type transistors were constructed by embedding the graphene/Ag hybrid fiber electrodes onto conventional polyurethane monofilaments, which exhibited excellent flexibility (highly bendable and rollable properties), high electrical performance (μh = 15.6 cm(2) V(-1) s(-1), Ion/Ioff > 10(4)), and outstanding device performance stability (stable after 1,000 cycles of bending tests and being exposed for 30 days to ambient conditions). We believe that our simple methods for the fabrication of graphene/Ag hybrid fiber electrodes for use in fiber-type transistors can potentially be applied to the development all-organic wearable devices.

Highly Conductive Graphene/Ag Hybrid Fibers for Flexible Fiber-Type Transistors

PubMed Central

Yoon, Sang Su; Lee, Kang Eun; Cha, Hwa-Jin; Seong, Dong Gi; Um, Moon-Kwang; Byun, Joon-Hyung; Oh, Youngseok; Oh, Joon Hak; Lee, Wonoh; Lee, Jea Uk

2015-01-01

Mechanically robust, flexible, and electrically conductive textiles are highly suitable for use in wearable electronic applications. In this study, highly conductive and flexible graphene/Ag hybrid fibers were prepared and used as electrodes for planar and fiber-type transistors. The graphene/Ag hybrid fibers were fabricated by the wet-spinning/drawing of giant graphene oxide and subsequent functionalization with Ag nanoparticles. The graphene/Ag hybrid fibers exhibited record-high electrical conductivity of up to 15,800 S cm−1. As the graphene/Ag hybrid fibers can be easily cut and placed onto flexible substrates by simply gluing or stitching, ion gel-gated planar transistors were fabricated by using the hybrid fibers as source, drain, and gate electrodes. Finally, fiber-type transistors were constructed by embedding the graphene/Ag hybrid fiber electrodes onto conventional polyurethane monofilaments, which exhibited excellent flexibility (highly bendable and rollable properties), high electrical performance (μh = 15.6 cm2 V−1 s−1, Ion/Ioff > 104), and outstanding device performance stability (stable after 1,000 cycles of bending tests and being exposed for 30 days to ambient conditions). We believe that our simple methods for the fabrication of graphene/Ag hybrid fiber electrodes for use in fiber-type transistors can potentially be applied to the development all-organic wearable devices. PMID:26549711

Fabrication of Organic Transistors Using Nanomaterials for Sensing Applications

NASA Astrophysics Data System (ADS)

Harb, Mohamed E.; Ebrahim, Shaker; Soliman, Moataz; Shabana, Mahmoud

2018-01-01

In this work, an organic field-effect transistor (OFET) was fabricated and characterized based on the bottom contact of a polyaniline (PANI) or PANI/TiO2 nanocomposite as an active layer and SiO2 as an insulating layer to be used for ammonia gas sensing applications. The OFET sensors exhibited a change in the drain current when exposed to NH3. Titanium dioxide (TiO2) nanoparticles with different weight percentages (0-50 wt.%) were added to dope PANI and enhance charge carrier transport, although the response of both the PANI OFET sensor and PANI/TiO2 OFET sensor has reached saturation value at almost the same period. The response of PANI/TiO2 transistor is (2.5), which is much higher than that of PANI (0.17). The results showed that the sensor response of the OFET device fabricated with PANI/TiO2 is 15 times greater than that with an OFET device fabricated using pristine PANI.

Transistor-based interface circuitry

DOEpatents

Taubman, Matthew S [Richland, WA

2007-02-13

Among the embodiments of the present invention is an apparatus that includes a transistor, a servo device, and a current source. The servo device is operable to provide a common base mode of operation of the transistor by maintaining an approximately constant voltage level at the transistor base. The current source is operable to provide a bias current to the transistor. A first device provides an input signal to an electrical node positioned between the emitter of the transistor and the current source. A second device receives an output signal from the collector of the transistor.

Morphological impact of zinc oxide layers on the device performance in thin-film transistors.

PubMed

Faber, Hendrik; Klaumünzer, Martin; Voigt, Michael; Galli, Diana; Vieweg, Benito F; Peukert, Wolfgang; Spiecker, Erdmann; Halik, Marcus

2011-03-01

Zinc oxide thin-films are prepared either by spin coating of an ethanolic dispersion of nanoparticles (NP, diameter 5 nm) or by spray pyrolysis of a zinc acetate dihydrate precursor. High-resolution electron microscopy studies reveal a monolayer of particles for the low temperature spin coating approach and larger crystalline domains of more than 30 nm for the spray pyrolysis technique. Thin-film transistor devices (TFTs) based on spray pyrolysis films exhibit higher electron mobilities of up to 24 cm2 V(-1) s(-1) compared to 0.6 cm2 V(-1) s(-1) for NP based TFTs. These observations were dedicated to a reduced number of grain boundaries within the transistor channel.

A study of thermal conductivity in graphene diodes and transistors with intrinsic defects and subjected to metal impurities

NASA Astrophysics Data System (ADS)

Sadeghzadeh, Sadegh; Rezapour, Navid

2016-12-01

In this paper, the effect of the presence of cavities resulting from the fabrication process and the effect of common metal impurities added during the synthesis process on the thermal conductivity of single-layer graphene sheets, diodes and transistors have been investigated by using the Reverse Non Equilibrium Molecular Dynamics (RNEMD) method. The obtained results show that thermal conductivity generally diminishes by increasing the concentration of nanoparticles and increases when porosities and impurities are at the edges of sheets. Regarding a better thermal management in graphene with the addition of nanoparticles, and considering its existing porosity, a lower thermal conductivity is achieved by adding more nanoparticles. By increasing the diameter of pores from 0.5 nm to 4.4 nm in a specific single-layer graphene sheet, thermal conductivity diminishes from 67 W/mk to 1.43 W/mk; while it diminishes from 45 to 1.0 W/mk for the same structure containing both the defects and nanoparticles over the defects. In evaluating the influences of cavities and metallic nanoparticles on thermal conductivity, it was observed that changing the share of cavities or nanoparticles has a significant effect on the thermal conductivity of graphene diodes and transistors. The rectification efficiency of diodes diminished from about 100% for the defect-free diode to about 19% for the diode containing 2 nm cavities and then increased to 75% for the diode with 5 nm cavities. While, with the increase in the concentration of iron nanoparticles, the rectification efficiency increased from about 100% for the diode with no iron particles to about 255% for the diode containing 13 wt % of iron particles. Final results demonstrate that the metallic nanoparticles and also defects with specific diameters can be effectively exploited to increase or decrease the efficiency of nanodiodes and nanotransistors. This leads to engineered design of nanodiodes and nanotransistors for various

Plasma-Assisted Atomic Layer Deposition of High-Density Ni Nanoparticles for Amorphous In-Ga-Zn-O Thin Film Transistor Memory

NASA Astrophysics Data System (ADS)

Qian, Shi-Bing; Wang, Yong-Ping; Shao, Yan; Liu, Wen-Jun; Ding, Shi-Jin

2017-02-01

For the first time, the growth of Ni nanoparticles (NPs) was explored by plasma-assisted atomic layer deposition (ALD) technique using NiCp2 and NH3 precursors. Influences of substrate temperature and deposition cycles on ALD Ni NPs were studied by field emission scanning electron microscope and X-ray photoelectron spectroscopy. By optimizing the process parameters, high-density and uniform Ni NPs were achieved in the case of 280 °C substrate temperature and 50 deposition cycles, exhibiting a density of 1.5 × 1012 cm-2 and a small size of 3 4 nm. Further, the above Ni NPs were used as charge storage medium of amorphous indium-gallium-zinc oxide (a-IGZO) thin film transistor (TFT) memory, demonstrating a high storage capacity for electrons. In particular, the nonvolatile memory exhibited an excellent programming characteristic, e.g., a large threshold voltage shift of 8.03 V was obtained after being programmed at 17 V for 5 ms.

VOLTAGE-CONTROLLED TRANSISTOR OSCILLATOR

DOEpatents

Scheele, P.F.

1958-09-16

This patent relates to transistor oscillators and in particular to those transistor oscillators whose frequencies vary according to controlling voltages. A principal feature of the disclosed transistor oscillator circuit resides in the temperature compensation of the frequency modulating stage by the use of a resistorthermistor network. The resistor-thermistor network components are selected to have the network resistance, which is in series with the modulator transistor emitter circuit, vary with temperature to compensate for variation in the parameters of the transistor due to temperature change.

Radiation-hardened transistor and integrated circuit

DOEpatents

Ma, Kwok K.

2007-11-20

A composite transistor is disclosed for use in radiation hardening a CMOS IC formed on an SOI or bulk semiconductor substrate. The composite transistor has a circuit transistor and a blocking transistor connected in series with a common gate connection. A body terminal of the blocking transistor is connected only to a source terminal thereof, and to no other connection point. The blocking transistor acts to prevent a single-event transient (SET) occurring in the circuit transistor from being coupled outside the composite transistor. Similarly, when a SET occurs in the blocking transistor, the circuit transistor prevents the SET from being coupled outside the composite transistor. N-type and P-type composite transistors can be used for each and every transistor in the CMOS IC to radiation harden the IC, and can be used to form inverters and transmission gates which are the building blocks of CMOS ICs.

The effects of transistor source-to-gate bridging faults in complex CMOS gates

NASA Astrophysics Data System (ADS)

Visweswaran, G. S.; Ali, Akhtar-Uz-Zaman M.; Lala, Parag K.; Hartmann, Carlos R. P.

1991-06-01

A study of the effect of gate-to-source bridging faults in the pull-up section of a complex CMOS gate is presented. The manifestation of these faults depends on the resistance value of the connection causing the bridging. It is shown that such faults manifest themselves either as stuck-at or stuck-open faults and can be detected by tests for stuck-at and stuck-open faults generated for the equivalent logic current. It is observed that for transistor channel lengths larger than 1 microns there exists a range of values of the bridging resistance for which the fault behaves as a pseudo-stuck-open fault.

Vertical plasmonic nanowires for 3D nanoparticle trapping

NASA Astrophysics Data System (ADS)

Wu, Jingzhi; Gan, Xiaosong

2011-12-01

Nanoparticle trapping is considered to be more challenging than trapping micron-sized objects because of the diffraction limit of light and the severe Brownian motion of the nanoparticles. We introduce a nanoparticle trapping approach based on plasmonic nanostructures, which consist of nanopillars with high aspect ratio. The plasmonic nanopillars behave as plasmonic resonators that rely on paired nano-pillars supporting gap plasmon modes. The localized surface plasmon resonance effect provides strong electromagnetic field enhancement and enables confinement of nanoparticles in three dimensional space. Numerical simulations indicate that the plasmonic structure provides stronger optical forces for trapping nanoparticles. The study of thermal effect of the plasmonic structure shows that the impact of the thermal force is significant, which may determine the outcome of the nanoparticle trapping.

Mobility Enhancement in Amorphous In-Ga-Zn-O Thin-Film Transistor by Induced Metallic in Nanoparticles and Cu Electrodes

PubMed Central

Lu, Kuankuan; Li, Yuzhi; Xu, Miao; Wang, Lei; Peng, Junbiao; Lu, Xubing

2018-01-01

In this work, we fabricated a high-mobility amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistor (TFT) based on alumina oxide (Al2O3) passivation layer (PVL) and copper (Cu) source/drain electrodes (S/D). The mechanism of the high mobility for a-IGZO TFT was proposed and experimentally demonstrated. The conductivity of the channel layer was significantly improved due to the formation of metallic In nanoparticles on the back channel during Al2O3 PVL sputtering. In addition, Ar atmosphere annealing induced the Schottky contact formation between the Cu S/D and the channel layer caused by Cu diffusion. In conjunction with high conductivity channel and Schottky contact, the a-IGZO TFT based on Cu S/D and Al2O3 PVL exhibited remarkable mobility of 33.5–220.1 cm2/Vs when channel length varies from 60 to 560 μm. This work presents a feasible way to implement high mobility and Cu electrodes in a-IGZO TFT, simultaneously. PMID:29584710

BehavePlus fire modeling system, version 5.0: Variables

Treesearch

Patricia L. Andrews

2009-01-01

This publication has been revised to reflect updates to version 4.0 of the BehavePlus software. It was originally published as the BehavePlus fire modeling system, version 4.0: Variables in July, 2008.The BehavePlus fire modeling system is a computer program based on mathematical models that describe wildland fire behavior and effects and the...

Temperature Dependence of Smectic Liquid Crystals Mixed With Magnetic Nanoparticles

NASA Astrophysics Data System (ADS)

Taylor, Jefferson W.; Kurihara, Lynn K.; Martinez-Miranda, Luz J.

2012-02-01

We investigate the properties of bulk liquid crystal mixed with a magnetic nanoparticle (CoFe) as a function of temperature. We compare our results to those of a heat capacity measurement of Cordoyiannis et al.ootnotetextGeorge Cordoyiannis, Lynn K. Kurihara, Luz J. Martinez-Miranda, Christ Glorieux, and Jan Thoen, Phys. Rev. E 79, 011702 (2009) and compare the way the smectic as a function of temperature the way the nematic behaves. We study how the liquid crystal reorganizes in the presence of the functionalized nanoparticles as a function of temperature and compare it to how it behaves at room temperature.ootnotetextL. J. Mart'inez-Miranda, and Lynn Kurihara, J. Appl. Phys, 105, p. 084305 (2009). The X-rays give rise to three or four peaks whose evolution in temperature varies depending on their origin. In particular the second peak does not seem to vary much with temperature, and can be associated with the first several molecular layers attached to the nanoparticles.

InGaP/InGaAs field-effect transistor typed hydrogen sensor

NASA Astrophysics Data System (ADS)

Tsai, Jung-Hui; Liou, Syuan-Hao; Lin, Pao-Sheng; Chen, Yu-Chi

2018-02-01

In this article, the Pd-based mixture comprising silicon dioxide (SiO2) is applied as sensing material for the InGaP/InGaAs field-effect transistor typed hydrogen sensor. After wet selectively etching the SiO2, the mixture is turned into Pd nanoparticles on an interlayer. Experimental results depict that hydrogen atoms trapped inside the mixture could effectively decrease the gate barrier height and increase the drain current due to the improved sensing properties when Pd nanoparticles were formed by wet etching method. The sensitivity of the gate forward current from air (the reference) to 9800 ppm hydrogen/air environment approaches the high value of 1674. Thus, the studied device shows a good potential for hydrogen sensor and integrated circuit applications.

Detection of glutamate and acetylcholine with organic electrochemical transistors based on conducting polymer/platinum nanoparticle composites.

PubMed

Kergoat, Loïg; Piro, Benoît; Simon, Daniel T; Pham, Minh-Chau; Noël, Vincent; Berggren, Magnus

2014-08-27

The aim of the study is to open a new scope for organic electrochemical transistors based on PEDOT:PSS, a material blend known for its stability and reliability. These devices can leverage molecular electrocatalysis by incorporating small amounts of nano-catalyst during the transistor manufacturing (spin coating). This methodology is very simple to implement using the know-how of nanochemistry and results in efficient enzymatic activity transduction, in this case utilizing choline oxidase and glutamate oxidase. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Copper atomic-scale transistors.

PubMed

Xie, Fangqing; Kavalenka, Maryna N; Röger, Moritz; Albrecht, Daniel; Hölscher, Hendrik; Leuthold, Jürgen; Schimmel, Thomas

2017-01-01

We investigated copper as a working material for metallic atomic-scale transistors and confirmed that copper atomic-scale transistors can be fabricated and operated electrochemically in a copper electrolyte (CuSO 4 + H 2 SO 4 ) in bi-distilled water under ambient conditions with three microelectrodes (source, drain and gate). The electrochemical switching-on potential of the atomic-scale transistor is below 350 mV, and the switching-off potential is between 0 and -170 mV. The switching-on current is above 1 μA, which is compatible with semiconductor transistor devices. Both sign and amplitude of the voltage applied across the source and drain electrodes ( U bias ) influence the switching rate of the transistor and the copper deposition on the electrodes, and correspondingly shift the electrochemical operation potential. The copper atomic-scale transistors can be switched using a function generator without a computer-controlled feedback switching mechanism. The copper atomic-scale transistors, with only one or two atoms at the narrowest constriction, were realized to switch between 0 and 1 G 0 ( G 0 = 2e 2 /h; with e being the electron charge, and h being Planck's constant) or 2 G 0 by the function generator. The switching rate can reach up to 10 Hz. The copper atomic-scale transistor demonstrates volatile/non-volatile dual functionalities. Such an optimal merging of the logic with memory may open a perspective for processor-in-memory and logic-in-memory architectures, using copper as an alternative working material besides silver for fully metallic atomic-scale transistors.

Copper atomic-scale transistors

PubMed Central

Kavalenka, Maryna N; Röger, Moritz; Albrecht, Daniel; Hölscher, Hendrik; Leuthold, Jürgen

2017-01-01

We investigated copper as a working material for metallic atomic-scale transistors and confirmed that copper atomic-scale transistors can be fabricated and operated electrochemically in a copper electrolyte (CuSO4 + H2SO4) in bi-distilled water under ambient conditions with three microelectrodes (source, drain and gate). The electrochemical switching-on potential of the atomic-scale transistor is below 350 mV, and the switching-off potential is between 0 and −170 mV. The switching-on current is above 1 μA, which is compatible with semiconductor transistor devices. Both sign and amplitude of the voltage applied across the source and drain electrodes (U bias) influence the switching rate of the transistor and the copper deposition on the electrodes, and correspondingly shift the electrochemical operation potential. The copper atomic-scale transistors can be switched using a function generator without a computer-controlled feedback switching mechanism. The copper atomic-scale transistors, with only one or two atoms at the narrowest constriction, were realized to switch between 0 and 1G 0 (G 0 = 2e2/h; with e being the electron charge, and h being Planck’s constant) or 2G 0 by the function generator. The switching rate can reach up to 10 Hz. The copper atomic-scale transistor demonstrates volatile/non-volatile dual functionalities. Such an optimal merging of the logic with memory may open a perspective for processor-in-memory and logic-in-memory architectures, using copper as an alternative working material besides silver for fully metallic atomic-scale transistors. PMID:28382242

Changes in Somatosensory Responsiveness in Behaving Primates

DTIC Science & Technology

1988-08-01

visually vs. vibratory-triggered movements; 2) to record from the cerebral cortex of awake , behaving monkeys during the performance of these sensory...vibratory-triggered movements; 2) to record from the cerebral cortex of awake , behaving monkeys during the performance of these sensory-triggered...recording chamber was implanted over the forelimb * region of the left sensorimotor cortices following a craniotomy and secured with smaller bolts and the

Mobility and Oxidation of Adsorbed CO on Shape-Controlled Pt Nanoparticles in Acidic Medium.

PubMed

Farias, Manuel J S; Busó-Rogero, Carlos; Vidal-Iglesias, Francisco J; Solla-Gullón, José; Camara, Giuseppe A; Feliu, Juan M

2017-01-31

The knowledge about how CO occupies and detaches from specific surface sites on well-structured Pt surfaces provides outstanding information on both dynamics/mobility of CO ads and oxidation of this molecule under electrochemical conditions. This work reports how the potentiostatic growth of different coverage CO adlayers evolves with time on both cubic and octahedral Pt nanoparticles in acidic medium. Data suggest that during the growth of the CO adlayer, CO ads molecules slightly shift toward low coordination sites only on octahedral Pt nanoparticles, so that these undercoordinated sites are the first filled on octahedral Pt nanoparticles. Conversely, on cubic Pt nanoparticles, adsorbed CO behaves as an immobile species, and low coordinated sites as well as (100) terraces are apparently filled uniformly and simultaneously. However, once the adlayer is complete, irrespectively of whether the CO is oxidized in a single step or in a sequence of different potential steps, results suggest that CO ads behaves as an immobile species during its oxidation on both octahedral and cubic Pt nanoparticles.

Detection of IL-6 by magnetic nanoparticles grown with the assistance of mid-infrared lighting.

PubMed

Jiang, Xiufeng; Zhang, Ye; Miao, Xiaofei; Li, Zenghui; Bao, Zengtao; Wang, Tong

2013-01-01

Nanomedical systems have attracted considerable attention primarily due to suitability in applications for specific cell selection through biomolecular targeting and rare cell detection enhancement in a diverse, multicellular population. In the present study, magnetic nanoparticles were prepared for use in high accuracy cell sensing. Magnetic nanoparticle growth was assisted by mid-infrared lighting. By this mechanism, a narrow window, estimated to be 2%, was achieved for the dimension distribution of grown nanoparticles. Combined with silicon nanowire (SiNW) transistors, a sensor with ultra high sensitivity for the detection of specific potential low abundance biomarkers has been achieved, which has been specifically used to detect interleukin-6 (IL-6) at extremely low concentrations. A novel biosensor with high sensitivity has been fabricated and utilized in the detection of IL-6 at 75 fM to 50 pM. The system consists of an SiNW transistor and magnetic nanoparticles with even dimension distribution. The novel sensor system is suitable for quantifying IL-6 at low concentrations in protein samples.

Plasma-Assisted Atomic Layer Deposition of High-Density Ni Nanoparticles for Amorphous In-Ga-Zn-O Thin Film Transistor Memory.

PubMed

Qian, Shi-Bing; Wang, Yong-Ping; Shao, Yan; Liu, Wen-Jun; Ding, Shi-Jin

2017-12-01

For the first time, the growth of Ni nanoparticles (NPs) was explored by plasma-assisted atomic layer deposition (ALD) technique using NiCp 2 and NH 3 precursors. Influences of substrate temperature and deposition cycles on ALD Ni NPs were studied by field emission scanning electron microscope and X-ray photoelectron spectroscopy. By optimizing the process parameters, high-density and uniform Ni NPs were achieved in the case of 280 °C substrate temperature and 50 deposition cycles, exhibiting a density of ~1.5 × 10 12  cm -2 and a small size of 3~4 nm. Further, the above Ni NPs were used as charge storage medium of amorphous indium-gallium-zinc oxide (a-IGZO) thin film transistor (TFT) memory, demonstrating a high storage capacity for electrons. In particular, the nonvolatile memory exhibited an excellent programming characteristic, e.g., a large threshold voltage shift of 8.03 V was obtained after being programmed at 17 V for 5 ms.

Changes in Sensory Responsiveness in Behaving Primates.

DTIC Science & Technology

1986-07-14

controlled behavioral training and monitoring, and electrophysiological recording in awake , behaving monkeys. All I, research equipment listed in the original...recording from the sensorimotor cortices was conducted on May 21. Under general anesthesia, a craniotomy was performed over the pre- and postcentral cortices...Department of Neurosurgery at U.T. Dr. Klein is somewhat unusual in that he has had previous experience recording from awake , behaving monkeys. The experience

Realization of Molecular-Based Transistors.

PubMed

Richter, Shachar; Mentovich, Elad; Elnathan, Roey

2018-06-06

Molecular-based devices are widely considered as significant candidates to play a role in the next generation of "post-complementary metal-oxide-semiconductor" devices. In this context, molecular-based transistors: molecular junctions that can be electrically gated-are of particular interest as they allow new modes of operation. The properties of molecular transistors composed of a single- or multimolecule assemblies, focusing on their practicality as real-world devices, concerning industry demands and its roadmap are compared. Also, the capability of the gate electrode to modulate the molecular transistor characteristics efficiently is addressed, showing that electrical gating can be easily facilitated in single molecular transistors and that gating of transistor composed of molecular assemblies is possible if the device is formed vertically. It is concluded that while the single-molecular transistor exhibits better performance on the lab-scale, its realization faces signifacant challenges when compared to those faced by transistors composed of a multimolecule assembly. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Glomerular barrier behaves as an atomically precise bandpass filter in a sub-nanometre regime

NASA Astrophysics Data System (ADS)

Du, Bujie; Jiang, Xingya; Das, Anindita; Zhou, Qinhan; Yu, Mengxiao; Jin, Rongchao; Zheng, Jie

2017-11-01

The glomerular filtration barrier is known as a 'size cutoff' slit, which retains nanoparticles or proteins larger than 6-8 nm in the body and rapidly excretes smaller ones through the kidneys. However, in the sub-nanometre size regime, we have found that this barrier behaves as an atomically precise 'bandpass' filter to significantly slow down renal clearance of few-atom gold nanoclusters (AuNCs) with the same surface ligands but different sizes (Au18, Au15 and Au10-11). Compared to Au25 (∼1.0 nm), just few-atom decreases in size result in four- to ninefold reductions in renal clearance efficiency in the early elimination stage, because the smaller AuNCs are more readily trapped by the glomerular glycocalyx than larger ones. This unique in vivo nano-bio interaction in the sub-nanometre regime also slows down the extravasation of sub-nanometre AuNCs from normal blood vessels and enhances their passive targeting to cancerous tissues through an enhanced permeability and retention effect. This discovery highlights the size precision in the body's response to nanoparticles and opens a new pathway to develop nanomedicines for many diseases associated with glycocalyx dysfunction.

Evolvable circuit with transistor-level reconfigurability

NASA Technical Reports Server (NTRS)

Stoica, Adrian (Inventor); Salazar-Lazaro, Carlos Harold (Inventor)

2004-01-01

An evolvable circuit includes a plurality of reconfigurable switches, a plurality of transistors within a region of the circuit, the plurality of transistors having terminals, the plurality of transistors being coupled between a power source terminal and a power sink terminal so as to be capable of admitting power between the power source terminal and the power sink terminal, the plurality of transistors being coupled so that every transistor terminal to transistor terminal coupling within the region of the circuit comprises a reconfigurable switch.

Interband Lateral Resonant Tunneling Transistor.

DTIC Science & Technology

1994-11-14

INTERBAND LATERAL RESONANT TUNNELING TRANSISTOR 10 BACKGROUND OF THE INVENTION Field of the Invention This invention pertains to a tunneling transistor...and in 15 particular to an interband lateral resonant tunneling transistor. Description of Related Art Conventional semiconductor technologies are... interband lateral resonant tunneling transistor along the cross-section B-B of Figure 2c. Figure 4 is another preferred embodiment cross-sectional 20

Highly sensitive protein detection using a plasmonic field effect transistor (Conference Presentation)

NASA Astrophysics Data System (ADS)

Shokri-Kojori, Hossein; Ji, Yiwen; Han, Xu; Paik, Younghun; Braunschweig, Adam; Kim, Sung Jin

2016-03-01

Localized surface Plasmon Resonance (LSPR) is a nanoscale phenomenon which presents strong resonance associated with noble metal nanostructures. This plasmon resonance based technology enables highly sensitive detection for chemical and biological applications. Recently, we have developed a plasmon field effect transistor (FET) that enables direct plasmonic-to-electric signal conversion with signal amplification. The plasmon FET consists of back-gated field effect transistor incorporated with gold nanoparticles on top of the FET channel. The gold nanostructures are physically separated from transistor electrodes and can be functionalized for a specific biological application. In this presentation, we report a successful demonstration of a model system to detect Con A proteins using Carbohydrate linkers as a capture molecule. The plasmon FET detected a very low concentration of Con A (0.006 mg/L) while it offers a wide dynamic range of 0.006-50 mg/L. In this demonstration, we used two-color light sources instead of a bulky spectrometer to achieve high sensitivity and wide dynamic range. The details of two-color based differential measurement method will be discussed. This novel protein-based sensor has several advantages such as extremely small size for point-of-care system, multiplexing capability, no need of complex optical geometry.

Thermometry of Silicon Nanoparticles

NASA Astrophysics Data System (ADS)

Mecklenburg, Matthew; Zutter, Brian; Regan, B. C.

2018-01-01

Current thermometry techniques lack the spatial resolution required to see the temperature gradients in typical, highly scaled modern transistors. As a step toward addressing this problem, we measure the temperature dependence of the volume plasmon energy in silicon nanoparticles from room temperature to 1250 °C , using a chip-style heating sample holder in a scanning transmission electron microscope (STEM) equipped with electron energy loss spectroscopy (EELS). The plasmon energy changes as expected for an electron gas subject to the thermal expansion of silicon. Reversing this reasoning, we find that measurements of the plasmon energy provide an independent measure of the nanoparticle temperature consistent with that of the heater chip's macroscopic, dual-function heater-and-thermometer to within the 5% accuracy of the thermometer's calibration. Thus, silicon has the potential to provide its own high-spatial-resolution thermometric readout signal via measurements of its volume plasmon energy. Furthermore, nanoparticles can, in general, serve as convenient nanothermometers for in situ electron-microscopy experiments.

High-performance vertical organic transistors.

PubMed

Kleemann, Hans; Günther, Alrun A; Leo, Karl; Lüssem, Björn

2013-11-11

Vertical organic thin-film transistors (VOTFTs) are promising devices to overcome the transconductance and cut-off frequency restrictions of horizontal organic thin-film transistors. The basic physical mechanisms of VOTFT operation, however, are not well understood and VOTFTs often require complex patterning techniques using self-assembly processes which impedes a future large-area production. In this contribution, high-performance vertical organic transistors comprising pentacene for p-type operation and C60 for n-type operation are presented. The static current-voltage behavior as well as the fundamental scaling laws of such transistors are studied, disclosing a remarkable transistor operation with a behavior limited by injection of charge carriers. The transistors are manufactured by photolithography, in contrast to other VOTFT concepts using self-assembled source electrodes. Fluorinated photoresist and solvent compounds allow for photolithographical patterning directly and strongly onto the organic materials, simplifying the fabrication protocol and making VOTFTs a prospective candidate for future high-performance applications of organic transistors. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Facile one-step synthesis of magnesium-doped ZnO nanoparticles: optical properties and their device applications

NASA Astrophysics Data System (ADS)

Oh, Ji-Young; Lim, Sang-Chul; Ahn, Seong Deok; Lee, Sang Seok; Cho, Kyoung-Ik; Bon Koo, Jae; Choi, Rino; Hasan, Musarrat

2013-07-01

In this study, magnesium-doped (Mg-doped) zinc oxide (ZnO) nanoparticles were successfully synthesized by a sonochemical process under mild conditions. The x-ray diffraction pattern indicated that the Mg-doped ZnO nanoparticles maintain a wurtzite structure without impurities. We observed a blue-shift of the bandgap of the Mg-doped ZnO nanoparticles as the Mg-doping ratio increased. We also fabricated thin-film transistor (TFT) devices with the doped-ZnO nanoparticles. Devices using Mg-doped ZnO nanoparticles as a channel layer showed insensibility to white-light irradiation compared with undoped ZnO TFTs.

Vertical organic transistors.

PubMed

Lüssem, Björn; Günther, Alrun; Fischer, Axel; Kasemann, Daniel; Leo, Karl

2015-11-11

Organic switching devices such as field effect transistors (OFETs) are a key element of future flexible electronic devices. So far, however, a commercial breakthrough has not been achieved because these devices usually lack in switching speed (e.g. for logic applications) and current density (e.g. for display pixel driving). The limited performance is caused by a combination of comparatively low charge carrier mobilities and the large channel length caused by the need for low-cost structuring. Vertical Organic Transistors are a novel technology that has the potential to overcome these limitations of OFETs. Vertical Organic Transistors allow to scale the channel length of organic transistors into the 100 nm regime without cost intensive structuring techniques. Several different approaches have been proposed in literature, which show high output currents, low operation voltages, and comparatively high speed even without sub-μm structuring technologies. In this review, these different approaches are compared and recent progress is highlighted.

Highly sensitive glucose sensors based on enzyme-modified whole-graphene solution-gated transistors

NASA Astrophysics Data System (ADS)

Zhang, Meng; Liao, Caizhi; Mak, Chun Hin; You, Peng; Mak, Chee Leung; Yan, Feng

2015-02-01

Noninvasive glucose detections are convenient techniques for the diagnosis of diabetes mellitus, which require high performance glucose sensors. However, conventional electrochemical glucose sensors are not sensitive enough for these applications. Here, highly sensitive glucose sensors are successfully realized based on whole-graphene solution-gated transistors with the graphene gate electrodes modified with an enzyme glucose oxidase. The sensitivity of the devices is dramatically improved by co-modifying the graphene gates with Pt nanoparticles due to the enhanced electrocatalytic activity of the electrodes. The sensing mechanism is attributed to the reaction of H2O2 generated by the oxidation of glucose near the gate. The optimized glucose sensors show the detection limits down to 0.5 μM and good selectivity, which are sensitive enough for non-invasive glucose detections in body fluids. The devices show the transconductances two orders of magnitude higher than that of a conventional silicon field effect transistor, which is the main reason for their high sensitivity. Moreover, the devices can be conveniently fabricated with low cost. Therefore, the whole-graphene solution-gated transistors are a high-performance sensing platform for not only glucose detections but also many other types of biosensors that may find practical applications in the near future.

Highly sensitive glucose sensors based on enzyme-modified whole-graphene solution-gated transistors

PubMed Central

Zhang, Meng; Liao, Caizhi; Mak, Chun Hin; You, Peng; Mak, Chee Leung; Yan, Feng

2015-01-01

Noninvasive glucose detections are convenient techniques for the diagnosis of diabetes mellitus, which require high performance glucose sensors. However, conventional electrochemical glucose sensors are not sensitive enough for these applications. Here, highly sensitive glucose sensors are successfully realized based on whole-graphene solution-gated transistors with the graphene gate electrodes modified with an enzyme glucose oxidase. The sensitivity of the devices is dramatically improved by co-modifying the graphene gates with Pt nanoparticles due to the enhanced electrocatalytic activity of the electrodes. The sensing mechanism is attributed to the reaction of H2O2 generated by the oxidation of glucose near the gate. The optimized glucose sensors show the detection limits down to 0.5 μM and good selectivity, which are sensitive enough for non-invasive glucose detections in body fluids. The devices show the transconductances two orders of magnitude higher than that of a conventional silicon field effect transistor, which is the main reason for their high sensitivity. Moreover, the devices can be conveniently fabricated with low cost. Therefore, the whole-graphene solution-gated transistors are a high-performance sensing platform for not only glucose detections but also many other types of biosensors that may find practical applications in the near future. PMID:25655666

Low voltage operation of IGZO thin film transistors enabled by ultrathin Al2O3 gate dielectric

NASA Astrophysics Data System (ADS)

Ma, Pengfei; Du, Lulu; Wang, Yiming; Jiang, Ran; Xin, Qian; Li, Yuxiang; Song, Aimin

2018-01-01

An ultrathin, 5 nm, Al2O3 film grown by atomic-layer deposition was used as a gate dielectric for amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs). The Al2O3 layer showed a low surface roughness of 0.15 nm, a low leakage current, and a high breakdown voltage of 6 V. In particular, a very high gate capacitance of 720 nF/cm2 was achieved, making it possible for the a-IGZO TFTs to not only operate at a low voltage of 1 V but also exhibit desirable properties including a low threshold voltage of 0.3 V, a small subthreshold swing of 100 mV/decade, and a high on/off current ratio of 1.2 × 107. Furthermore, even under an ultralow operation voltage of 0.6 V, well-behaved transistor characteristics were still observed with an on/off ratio as high as 3 × 106. The electron transport through the Al2O3 layer has also been analyzed, indicating the Fowler-Nordheim tunneling mechanism.

Numerical investigation for one bad-behaved flow in a Pelton turbine

NASA Astrophysics Data System (ADS)

Wei, X. Z.; Yang, K.; Wang, H. J.; Gong, R. Z.; Li, D. Y.

2015-01-01

The gas-liquid two-phase flow in pelton turbines is very complicated, there are many kinds of bad-behaved flow in pelton turbines. In this paper, CFD numerical simulation for the pelton turbine was conducted using VOF two-phase model. One kind of bad-behaved flow caused by the two jets was captured, and the bad-behaved flow was analysed by torque on buckets. It can be concluded that the angle between the two jets and the value of ratio of runner diameter and jet diameter are important parameters for the bad-behaved flow. Furthermore, the reason why the efficiency of some multi-jet type turbines is very low can be well explained by the analysis of bad-behaved flow. Finally, some suggestions for improvement were also provided in present paper.

P-channel thin film transistors using reduced graphene oxide

NASA Astrophysics Data System (ADS)

Chakraborty, S.; Resmi, A. N.; Renuka Devi, P.; Jinesh, K. B.

2017-04-01

Chemically reduced graphene oxide (rGO) samples with various degrees of reduction were prepared using hydrazine hydrate as the reducing agent. Scanning tunnelling microscope imaging shows that rGO contains rows of randomly distributed patches of epoxy groups. The local density of states of the rGO samples were mapped with scanning tunnelling spectroscopy, which shows that the bandgap in rGO originates from the epoxide regions itself. The Fermi level of the epoxide regions is shifted towards the valence band, making rGO locally p-type and a range of bandgaps from 0-2.2 eV was observed in these regions. Thin film transistors were fabricated using rGO as the channel layer. The devices show excellent output characteristics with clear saturation and gate dependence. The transfer characteristics show that rGO behaves as a p-type semiconductor; the devices exhibit an on/off ratio of 104, with a low-bias hole mobility of 3.9 cm2 V-1 s-1.

Transistor-based particle detection systems and methods

DOEpatents

Jain, Ankit; Nair, Pradeep R.; Alam, Muhammad Ashraful

2015-06-09

Transistor-based particle detection systems and methods may be configured to detect charged and non-charged particles. Such systems may include a supporting structure contacting a gate of a transistor and separating the gate from a dielectric of the transistor, and the transistor may have a near pull-in bias and a sub-threshold region bias to facilitate particle detection. The transistor may be configured to change current flow through the transistor in response to a change in stiffness of the gate caused by securing of a particle to the gate, and the transistor-based particle detection system may configured to detect the non-charged particle at least from the change in current flow.

High work function materials for source/drain contacts in printed polymer thin film transistors

NASA Astrophysics Data System (ADS)

Sholin, V.; Carter, S. A.; Street, R. A.; Arias, A. C.

2008-02-01

Studies of materials for source-drain electrodes in ink-jet printed polymer-based thin film transistors (TFTs) are reported. Two systems are studied: a blend of Ag nanoparticles with poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) and an ethylene glycol-doped PEDOT:PSS solution (modified-PEDOT). The semiconductor used is the polythiophene derivative poly [5,5'-bis(3-dodecyl-2-thienyl)-2,2,2'-bithiophene]. PEDOT:Ag blends and modified-PEDOT yield TFTs with mobilities around 10-2 and 10-3cm2/Vs, respectively, subthreshold slopes around 1.6V/decade and on-to-off current ratios of 106-107. Both systems show considerable improvement over printed TFTs with Ag nanoparticle source-drain electrodes. Results on film resistivity and morphology are discussed along with device characteristic analysis.

High voltage power transistor development

NASA Technical Reports Server (NTRS)

Hower, P. L.

1981-01-01

Design considerations, fabrication procedures, and methods of evaluation for high-voltage power-transistor development are discussed. Technique improvements such as controlling the electric field at the surface and perserving lifetimes in the collector region which have advanced the state of the art in high-voltage transistors are discussed. These improvements can be applied directly to the development of 1200 volt, 200 ampere transistors.

Chemoelectronic circuits based on metal nanoparticles

NASA Astrophysics Data System (ADS)

Yan, Yong; Warren, Scott C.; Fuller, Patrick; Grzybowski, Bartosz A.

2016-07-01

To develop electronic devices with novel functionalities and applications, various non-silicon-based materials are currently being explored. Nanoparticles have unique characteristics due to their small size, which can impart functions that are distinct from those of their bulk counterparts. The use of semiconductor nanoparticles has already led to improvements in the efficiency of solar cells, the processability of transistors and the sensitivity of photodetectors, and the optical and catalytic properties of metal nanoparticles have led to similar advances in plasmonics and energy conversion. However, metals screen electric fields and this has, so far, prevented their use in the design of all-metal nanoparticle circuitry. Here, we show that simple electronic circuits can be made exclusively from metal nanoparticles functionalized with charged organic ligands. In these materials, electronic currents are controlled by the ionic gradients of mobile counterions surrounding the ‘jammed’ nanoparticles. The nanoparticle-based electronic elements of the circuitry can be interfaced with metal nanoparticles capable of sensing various environmental changes (humidity, gas, the presence of various cations), creating electronic devices in which metal nanoparticles sense, process and ultimately report chemical signals. Because the constituent nanoparticles combine electronic and chemical sensing functions, we term these systems ‘chemoelectronic’. The circuits have switching times comparable to those of polymer electronics, selectively transduce parts-per-trillion chemical changes into electrical signals, perform logic operations, consume little power (on the scale of microwatts), and are mechanically flexible. They are also ‘green’, in the sense that they comprise non-toxic nanoparticles cast at room temperature from alcohol solutions.

Chemoelectronic circuits based on metal nanoparticles.

PubMed

Yan, Yong; Warren, Scott C; Fuller, Patrick; Grzybowski, Bartosz A

2016-07-01

To develop electronic devices with novel functionalities and applications, various non-silicon-based materials are currently being explored. Nanoparticles have unique characteristics due to their small size, which can impart functions that are distinct from those of their bulk counterparts. The use of semiconductor nanoparticles has already led to improvements in the efficiency of solar cells, the processability of transistors and the sensitivity of photodetectors, and the optical and catalytic properties of metal nanoparticles have led to similar advances in plasmonics and energy conversion. However, metals screen electric fields and this has, so far, prevented their use in the design of all-metal nanoparticle circuitry. Here, we show that simple electronic circuits can be made exclusively from metal nanoparticles functionalized with charged organic ligands. In these materials, electronic currents are controlled by the ionic gradients of mobile counterions surrounding the 'jammed' nanoparticles. The nanoparticle-based electronic elements of the circuitry can be interfaced with metal nanoparticles capable of sensing various environmental changes (humidity, gas, the presence of various cations), creating electronic devices in which metal nanoparticles sense, process and ultimately report chemical signals. Because the constituent nanoparticles combine electronic and chemical sensing functions, we term these systems 'chemoelectronic'. The circuits have switching times comparable to those of polymer electronics, selectively transduce parts-per-trillion chemical changes into electrical signals, perform logic operations, consume little power (on the scale of microwatts), and are mechanically flexible. They are also 'green', in the sense that they comprise non-toxic nanoparticles cast at room temperature from alcohol solutions.

Silicon on insulator self-aligned transistors

DOEpatents

McCarthy, Anthony M.

2003-11-18

A method for fabricating thin-film single-crystal silicon-on-insulator (SOI) self-aligned transistors. Standard processing of silicon substrates is used to fabricate the transistors. Physical spaces, between the source and gate, and the drain and gate, introduced by etching the polysilicon gate material, are used to provide connecting implants (bridges) which allow the transistor to perform normally. After completion of the silicon substrate processing, the silicon wafer is bonded to an insulator (glass) substrate, and the silicon substrate is removed leaving the transistors on the insulator (glass) substrate. Transistors fabricated by this method may be utilized, for example, in flat panel displays, etc.

Single-transistor-clocked flip-flop

DOEpatents

Zhao, Peiyi; Darwish, Tarek; Bayoumi, Magdy

2005-08-30

The invention provides a low power, high performance flip-flop. The flip-flop uses only one clocked transistor. The single clocked transistor is shared by the first and second branches of the device. A pulse generator produces a clock pulse to trigger the flip-flop. In one preferred embodiment the device can be made as a static explicit pulsed flip-flop which employs only two clocked transistors.

Patterning Method for Silver Nanoparticle Electrodes in Fully Solution-Processed Organic Thin-Film Transistors Using Selectively Treated Hydrophilic and Hydrophobic Surfaces

NASA Astrophysics Data System (ADS)

Fukuda, Kenjiro; Takeda, Yasunori; Kobayashi, Yu; Shimizu, Masahiro; Sekine, Tomohito; Kumaki, Daisuke; Kurihara, Masato; Sakamoto, Masatomi; Tokito, Shizuo

2013-05-01

Fully solution-processed organic thin-film transistor (OTFT) devices have been fabricated with simple patterning process at a relatively low process temperature of 100 °C. In the patterning process, a hydrophobic amorphous fluoropolymer material, which was used as the gate dielectric layer and the underlying base layer, was treated with an oxygen plasma to selectively change its surface wetting properties from hydrophobic to hydrophilic. Silver source and drain electrodes were successfully formed in the treated areas with highly uniform line widths and without residues between the electrodes. Nonuniformities in the thickness of the silver electrodes originating from the “coffee-ring” effect were suppressed by optimizing the blend of solvents used with the silver nanoparticles, such that the printed electrodes are appropriate for bottom-gate OTFT devices. A fully solution-processed OTFT device using a polymer semiconductor material (PB16TTT) exhibited good electrical performance with no hysteresis in its transfer characteristics and with good linearity in its output characteristics. A relatively high carrier mobility of 0.14 cm2 V-1 s-1 and an on/off ratio of 1×105 were obtained with the fabricated TFT device.

Complementary spin transistor using a quantum well channel.

PubMed

Park, Youn Ho; Choi, Jun Woo; Kim, Hyung-Jun; Chang, Joonyeon; Han, Suk Hee; Choi, Heon-Jin; Koo, Hyun Cheol

2017-04-20

In order to utilize the spin field effect transistor in logic applications, the development of two types of complementary transistors, which play roles of the n- and p-type conventional charge transistors, is an essential prerequisite. In this research, we demonstrate complementary spin transistors consisting of two types of devices, namely parallel and antiparallel spin transistors using InAs based quantum well channels and exchange-biased ferromagnetic electrodes. In these spin transistors, the magnetization directions of the source and drain electrodes are parallel or antiparallel, respectively, depending on the exchange bias field direction. Using this scheme, we also realize a complementary logic operation purely with spin transistors controlled by the gate voltage, without any additional n- or p-channel transistor.

Ambipolar organic thin-film transistor-based nano-floating-gate nonvolatile memory

NASA Astrophysics Data System (ADS)

Han, Jinhua; Wang, Wei; Ying, Jun; Xie, Wenfa

2014-01-01

An ambipolar organic thin-film transistor-based nano-floating-gate nonvolatile memory was demonstrated, with discrete distributed gold nanoparticles, tetratetracontane (TTC), pentacene as the floating-gate layer, tunneling layer, and active layer, respectively. The electron traps at the TTC/pentacene interface were significantly suppressed, which resulted in an ambipolar operation in present memory. As both electrons and holes were supplied in the channel and trapped in the floating-gate by programming/erasing operations, respectively, i.e., one type of charge carriers was used to overwrite the other, trapped, one, a large memory window, extending on both sides of the initial threshold voltage, was realized.

Shape Matters: Intravital Microscopy Reveals Surprising Geometrical Dependence for Nanoparticles in Tumor Models of Extravasation

PubMed Central

Smith, Bryan Ronain; Kempen, Paul; Bouley, Donna; Xu, Alexander; Liu, Zhuang; Melosh, Nicholas; Dai, Hongjie; Sinclair, Robert; Gambhir, Sanjiv Sam

2012-01-01

Delivery is one of the most critical obstacles confronting nanoparticle use in cancer diagnosis and therapy. For most oncological applications, nanoparticles must extravasate in order to reach tumor cells and perform their designated task. However, little understanding exists regarding the effect of nanoparticle shape on extravasation. Herein we use real-time intravital microscopic imaging to meticulously examine how two different nanoparticles behave across three different murine tumor models. The study quantitatively demonstrates that high-aspect ratio single-walled carbon nanotubes (SWNTs) display extravasational behavior surprisingly different from, and counterintuitive to, spherical nanoparticles although the nanoparticles have similar surface coatings, area, and charge. This work quantitatively indicates that nanoscale extravasational competence is highly dependent on nanoparticle geometry and is heterogeneous. PMID:22650417

Aerosol jet printed p- and n-type electrolyte-gated transistors with a variety of electrode materials: exploring practical routes to printed electronics.

PubMed

Hong, Kihyon; Kim, Se Hyun; Mahajan, Ankit; Frisbie, C Daniel

2014-11-12

Printing electrically functional liquid inks is a promising approach for achieving low-cost, large-area, additive manufacturing of flexible electronic circuits. To print thin-film transistors, a basic building block of thin-film electronics, it is important to have several options for printable electrode materials that exhibit high conductivity, high stability, and low-cost. Here we report completely aerosol jet printed (AJP) p- and n-type electrolyte-gated transistors (EGTs) using a variety of different electrode materials including highly conductive metal nanoparticles (Ag), conducting polymers (polystyrenesulfonate doped poly(3,4-ethylendedioxythiophene, PEDOT:PSS), transparent conducting oxides (indium tin oxide), and carbon-based materials (reduced graphene oxide). Using these source-drain electrode materials and a PEDOT:PSS/ion gel gate stack, we demonstrated all-printed p- and n-type EGTs in combination with poly(3-hexythiophene) and ZnO semiconductors. All transistor components (including electrodes, semiconductors, and gate insulators) were printed by AJP. Both kinds of devices showed typical p- and n-type transistor characteristics, and exhibited both low-threshold voltages (<2 V) and high hole and electron mobilities. Our assessment suggests Ag electrodes may be the best option in terms of overall performance for both types of EGTs.

TRANSISTOR HIGH VOLTAGE POWER SUPPLY

DOEpatents

Driver, G.E.

1958-07-15

High voltage, direct current power supplies are described for use with battery powered nuclear detection equipment. The particular advantages of the power supply described, are increased efficiency and reduced size and welght brought about by the use of transistors in the circuit. An important feature resides tn the employment of a pair of transistors in an alternatefiring oscillator circuit having a coupling transformer and other circuit components which are used for interconnecting the various electrodes of the transistors.

The strain and thermal induced tunable charging phenomenon in low power flexible memory arrays with a gold nanoparticle monolayer

NASA Astrophysics Data System (ADS)

Zhou, Ye; Han, Su-Ting; Xu, Zong-Xiang; Roy, V. A. L.

2013-02-01

The strain and temperature dependent memory effect of organic memory transistors on plastic substrates has been investigated under ambient conditions. The gold (Au) nanoparticle monolayer was prepared and embedded in an atomic layer deposited aluminum oxide (Al2O3) as the charge trapping layer. The devices exhibited low operation voltage, reliable memory characteristics and long data retention time. Experimental analysis of the programming and erasing behavior at various bending states showed the relationship between strain and charging capacity. Thermal-induced effects on these memory devices have also been analyzed. The mobility shows ~200% rise and the memory window increases from 1.48 V to 1.8 V when the temperature rises from 20 °C to 80 °C due to thermally activated transport. The retention capability of the devices decreases with the increased working temperature. Our findings provide a better understanding of flexible organic memory transistors under various operating temperatures and validate their applications in various areas such as temperature sensors, temperature memory or advanced electronic circuits. Furthermore, the low temperature processing procedures of the key elements (Au nanoparticle monolayer and Al2O3 dielectric layer) could be potentially integrated with large area flexible electronics.The strain and temperature dependent memory effect of organic memory transistors on plastic substrates has been investigated under ambient conditions. The gold (Au) nanoparticle monolayer was prepared and embedded in an atomic layer deposited aluminum oxide (Al2O3) as the charge trapping layer. The devices exhibited low operation voltage, reliable memory characteristics and long data retention time. Experimental analysis of the programming and erasing behavior at various bending states showed the relationship between strain and charging capacity. Thermal-induced effects on these memory devices have also been analyzed. The mobility shows ~200% rise and the

Photosensitive graphene transistors.

PubMed

Li, Jinhua; Niu, Liyong; Zheng, Zijian; Yan, Feng

2014-08-20

High performance photodetectors play important roles in the development of innovative technologies in many fields, including medicine, display and imaging, military, optical communication, environment monitoring, security check, scientific research and industrial processing control. Graphene, the most fascinating two-dimensional material, has demonstrated promising applications in various types of photodetectors from terahertz to ultraviolet, due to its ultrahigh carrier mobility and light absorption in broad wavelength range. Graphene field effect transistors are recognized as a type of excellent transducers for photodetection thanks to the inherent amplification function of the transistors, the feasibility of miniaturization and the unique properties of graphene. In this review, we will introduce the applications of graphene transistors as photodetectors in different wavelength ranges including terahertz, infrared, visible, and ultraviolet, focusing on the device design, physics and photosensitive performance. Since the device properties are closely related to the quality of graphene, the devices based on graphene prepared with different methods will be addressed separately with a view to demonstrating more clearly their advantages and shortcomings in practical applications. It is expected that highly sensitive photodetectors based on graphene transistors will find important applications in many emerging areas especially flexible, wearable, printable or transparent electronics and high frequency communications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Quantum Thermal Transistor.

PubMed

Joulain, Karl; Drevillon, Jérémie; Ezzahri, Younès; Ordonez-Miranda, Jose

2016-05-20

We demonstrate that a thermal transistor can be made up with a quantum system of three interacting subsystems, coupled to a thermal reservoir each. This thermal transistor is analogous to an electronic bipolar one with the ability to control the thermal currents at the collector and at the emitter with the imposed thermal current at the base. This is achieved by determining the heat fluxes by means of the strong-coupling formalism. For the case of three interacting spins, in which one of them is coupled to the other two, that are not directly coupled, it is shown that high amplification can be obtained in a wide range of energy parameters and temperatures. The proposed quantum transistor could, in principle, be used to develop devices such as a thermal modulator and a thermal amplifier in nanosystems.

Fabrication of flexible MoS2 thin-film transistor arrays for practical gas-sensing applications.

PubMed

He, Qiyuan; Zeng, Zhiyuan; Yin, Zongyou; Li, Hai; Wu, Shixin; Huang, Xiao; Zhang, Hua

2012-10-08

By combining two kinds of solution-processable two-dimensional materials, a flexible transistor array is fabricated in which MoS(2) thin film is used as the active channel and reduced graphene oxide (rGO) film is used as the drain and source electrodes. The simple device configuration and the 1.5 mm-long MoS(2) channel ensure highly reproducible device fabrication and operation. This flexible transistor array can be used as a highly sensitive gas sensor with excellent reproducibility. Compared to using rGO thin film as the active channel, this new gas sensor exhibits much higher sensitivity. Moreover, functionalization of the MoS(2) thin film with Pt nanoparticles further increases the sensitivity by up to ∼3 times. The successful incorporation of a MoS(2) thin-film into the electronic sensor promises its potential application in various electronic devices. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Boron nitride housing cools transistors

NASA Technical Reports Server (NTRS)

1965-01-01

Boron nitride ceramic heat sink cools transistors in r-f transmitter and receiver circuits. Heat dissipated by the transistor is conducted by the boron nitride housing to the metal chassis on which it is mounted.

A well-behaved class of charged analogue of Durgapal solution

NASA Astrophysics Data System (ADS)

Mehta, R. N.; Pant, Neeraj; Mahto, Dipo; Jha, J. S.

2013-02-01

We present a well behaved class of charged analogue of M.C. Durgapal (J. Phys. A, Math. Gen. 15:2637, 1982) solution. This solution describes charged fluid balls with positively finite central pressure, positively finite central density; their ratio is less than one and causality condition is obeyed at the centre. The outmarch of pressure, density, pressure-density ratio and the adiabatic speed of sound is monotonically decreasing, however, the electric intensity is monotonically increasing in nature. This solution gives us wide range of parameter for every positive value of n for which the solution is well behaved hence, suitable for modeling of super dense stars. Keeping in view of well behaved nature of this solution, one new class of solution is being studied extensively. Moreover, this class of solution gives us wide range of constant K (0≤ K≤2.2) for which the solution is well behaved hence, suitable for modeling of super dense stars like strange quark stars, neutron stars and pulsars. For this class of solution the mass of a star is maximized with all degree of suitability, compatible with quark stars, neutron stars and pulsars. By assuming the surface density ρ b =2×1014 g/cm3 (like, Brecher and Capocaso, Nature 259:377, 1976), corresponding to K=0 with X=0..235, the resulting well behaved model has the mass M=4.03 M Θ , radius r b =19.53 km and moment of inertia I=1.213×1046 g cm2; for K=1.5 with X=0.235, the resulting well behaved model has the mass M=4.43 M Θ , radius r b =18.04 km and moment of inertia I=1.136×1046 g cm2; for K=2.2 with X=0.235, the resulting well behaved model has the mass M=4.56 M Θ , radius r b =17.30 km and moment of inertia I=1.076×1046 g cm2. These values of masses and moment of inertia are found to be consistent with the crab pulsars.

The resonant body transistor.

PubMed

Weinstein, Dana; Bhave, Sunil A

2010-04-14

This paper introduces the resonant body transistor (RBT), a silicon-based dielectrically transduced nanoelectromechanical (NEM) resonator embedding a sense transistor directly into the resonator body. Combining the benefits of FET sensing with the frequency scaling capabilities and high quality factors (Q) of internal dielectrically transduced bar resonators, the resonant body transistor achieves >10 GHz frequencies and can be integrated into a standard CMOS process for on-chip clock generation, high-Q microwave circuits, fundamental quantum-state preparation and observation, and high-sensitivity measurements. An 11.7 GHz bulk-mode RBT is demonstrated with a quality factor Q of 1830, marking the highest frequency acoustic resonance measured to date on a silicon wafer.

Fabrication and functionalization of carbon nanotube field effect transistors for bio-sensing applications

NASA Astrophysics Data System (ADS)

Zhou, Jianyun

Single walled carbon nanotube based field effect transistors are fabricated using photolithography and electron beam lithography techniques. First catalyst islands are deposited onto the substrate using standard optical lithographic techniques, and the nanotubes are grown by catalytic chemical vapor deposition from the pre-patterned catalyst islands. After imaging the grown nanotubes, the metal contact electrodes are patterned using lithography, followed by metal deposition using a sputtering technique. Both single nanotube devices and nanotube film devices are fabricated using this method. The single nanotube devices can be semiconducting, ambipolar, or metallic, with the resistance ranging from tens of kilo ohms to a few mega ohms, while the film devices are generally metallic, with only a few kilo ohms of resistance. Semiconducting single nanotube devices are functionalized for sensor applications. An electrodeposition technique was developed to functionalize the nanotube with a few materials, including avidin, chitosan, and metal nanoparticles. Among them, metal nanoparticle deposition is the most successful, and both gold and silver nanoparticles have been successfully deposited onto the sidewalls of the nanotubes from an "in situ" sacrificial electrode. The size and density of the nanoparticles, to some extent, can be tailored by controlling the deposition voltage. The gold nanoparticles are generally spherical, while the silver nanoparticles have branching snowflake shapes. These nanoparticles change the ON-state conductance of the nanotube while maintaining its semiconducting characteristics. The gold nanoparticles on the nanotube sidewalls can serve as anchoring sites for thiol-terminated biomolecules to functionalize the device for biosensing purposes. Results have shown that the thiol-terminated molecules can bind to the Au nanoparticles; however, nonspecific binding to the SiO2 surface is still abundant. Therefore, a self assembled monolayer (SAM) of

Complementary junction heterostructure field-effect transistor

DOEpatents

Baca, Albert G.; Drummond, Timothy J.; Robertson, Perry J.; Zipperian, Thomas E.

1995-01-01

A complimentary pair of compound semiconductor junction heterostructure field-effect transistors and a method for their manufacture are disclosed. The p-channel junction heterostructure field-effect transistor uses a strained layer to split the degeneracy of the valence band for a greatly improved hole mobility and speed. The n-channel device is formed by a compatible process after removing the strained layer. In this manner, both types of transistors may be independently optimized. Ion implantation is used to form the transistor active and isolation regions for both types of complimentary devices. The invention has uses for the development of low power, high-speed digital integrated circuits.

Complementary junction heterostructure field-effect transistor

DOEpatents

Baca, A.G.; Drummond, T.J.; Robertson, P.J.; Zipperian, T.E.

1995-12-26

A complimentary pair of compound semiconductor junction heterostructure field-effect transistors and a method for their manufacture are disclosed. The p-channel junction heterostructure field-effect transistor uses a strained layer to split the degeneracy of the valence band for a greatly improved hole mobility and speed. The n-channel device is formed by a compatible process after removing the strained layer. In this manner, both types of transistors may be independently optimized. Ion implantation is used to form the transistor active and isolation regions for both types of complimentary devices. The invention has uses for the development of low power, high-speed digital integrated circuits. 10 figs.

Assessment of Phospohrene Field Effect Transistors

DTIC Science & Technology

2018-01-28

electronics industry. To this end, transistor test structures would initially be fabricated on phosphorene exfoliated from black phosphorus and, later, on...34Phosphorene FETs-Promising Transistors Based on a few Layers of Phosphorus Atoms," Nanjing Electronic Devices Institute, Nanjing, China, Jul. 2015...OH, Nov. 2015. J.C. M. Hwang, "Phosphorene Transistors-Transient or Lasting Electronics ?" Workshop Frontier Electronics , San Juan, PR, Dec. 2015

Oxide Based Transistor for Flexible Displays

DTIC Science & Technology

2014-09-15

thin film transistors (TFTs) for next generation display technologies. A detailed and comprehensive study was carried out to ascertain the process...Box 12211 Research Triangle Park, NC 27709-2211 Thin film transistors , flexible electronics, RF sputtering, Transparent amorphous oxide semiconductors...NC A&T and RTI, International investigated In free GaSnZnO (GSZO) material system, as the active channel in thin film transistors (TFTs) for next

Reconfigurable Complementary Logic Circuits with Ambipolar Organic Transistors

PubMed Central

Yoo, Hocheon; Ghittorelli, Matteo; Smits, Edsger C. P.; Gelinck, Gerwin H.; Lee, Han-Koo; Torricelli, Fabrizio; Kim, Jae-Joon

2016-01-01

Ambipolar organic electronics offer great potential for simple and low-cost fabrication of complementary logic circuits on large-area and mechanically flexible substrates. Ambipolar transistors are ideal candidates for the simple and low-cost development of complementary logic circuits since they can operate as n-type and p-type transistors. Nevertheless, the experimental demonstration of ambipolar organic complementary circuits is limited to inverters. The control of the transistor polarity is crucial for proper circuit operation. Novel gating techniques enable to control the transistor polarity but result in dramatically reduced performances. Here we show high-performance non-planar ambipolar organic transistors with electrical control of the polarity and orders of magnitude higher performances with respect to state-of-art split-gate ambipolar transistors. Electrically reconfigurable complementary logic gates based on ambipolar organic transistors are experimentally demonstrated, thus opening up new opportunities for ambipolar organic complementary electronics. PMID:27762321

Reconfigurable Complementary Logic Circuits with Ambipolar Organic Transistors.

PubMed

Yoo, Hocheon; Ghittorelli, Matteo; Smits, Edsger C P; Gelinck, Gerwin H; Lee, Han-Koo; Torricelli, Fabrizio; Kim, Jae-Joon

2016-10-20

Ambipolar organic electronics offer great potential for simple and low-cost fabrication of complementary logic circuits on large-area and mechanically flexible substrates. Ambipolar transistors are ideal candidates for the simple and low-cost development of complementary logic circuits since they can operate as n-type and p-type transistors. Nevertheless, the experimental demonstration of ambipolar organic complementary circuits is limited to inverters. The control of the transistor polarity is crucial for proper circuit operation. Novel gating techniques enable to control the transistor polarity but result in dramatically reduced performances. Here we show high-performance non-planar ambipolar organic transistors with electrical control of the polarity and orders of magnitude higher performances with respect to state-of-art split-gate ambipolar transistors. Electrically reconfigurable complementary logic gates based on ambipolar organic transistors are experimentally demonstrated, thus opening up new opportunities for ambipolar organic complementary electronics.

Ultra-high gain diffusion-driven organic transistor

PubMed Central

Torricelli, Fabrizio; Colalongo, Luigi; Raiteri, Daniele; Kovács-Vajna, Zsolt Miklós; Cantatore, Eugenio

2016-01-01

Emerging large-area technologies based on organic transistors are enabling the fabrication of low-cost flexible circuits, smart sensors and biomedical devices. High-gain transistors are essential for the development of large-scale circuit integration, high-sensitivity sensors and signal amplification in sensing systems. Unfortunately, organic field-effect transistors show limited gain, usually of the order of tens, because of the large contact resistance and channel-length modulation. Here we show a new organic field-effect transistor architecture with a gain larger than 700. This is the highest gain ever reported for organic field-effect transistors. In the proposed organic field-effect transistor, the charge injection and extraction at the metal–semiconductor contacts are driven by the charge diffusion. The ideal conditions of ohmic contacts with negligible contact resistance and flat current saturation are demonstrated. The approach is general and can be extended to any thin-film technology opening unprecedented opportunities for the development of high-performance flexible electronics. PMID:26829567

Ultra-high gain diffusion-driven organic transistor.

PubMed

Torricelli, Fabrizio; Colalongo, Luigi; Raiteri, Daniele; Kovács-Vajna, Zsolt Miklós; Cantatore, Eugenio

2016-02-01

Emerging large-area technologies based on organic transistors are enabling the fabrication of low-cost flexible circuits, smart sensors and biomedical devices. High-gain transistors are essential for the development of large-scale circuit integration, high-sensitivity sensors and signal amplification in sensing systems. Unfortunately, organic field-effect transistors show limited gain, usually of the order of tens, because of the large contact resistance and channel-length modulation. Here we show a new organic field-effect transistor architecture with a gain larger than 700. This is the highest gain ever reported for organic field-effect transistors. In the proposed organic field-effect transistor, the charge injection and extraction at the metal-semiconductor contacts are driven by the charge diffusion. The ideal conditions of ohmic contacts with negligible contact resistance and flat current saturation are demonstrated. The approach is general and can be extended to any thin-film technology opening unprecedented opportunities for the development of high-performance flexible electronics.

Ultra-high gain diffusion-driven organic transistor

NASA Astrophysics Data System (ADS)

Torricelli, Fabrizio; Colalongo, Luigi; Raiteri, Daniele; Kovács-Vajna, Zsolt Miklós; Cantatore, Eugenio

2016-02-01

Emerging large-area technologies based on organic transistors are enabling the fabrication of low-cost flexible circuits, smart sensors and biomedical devices. High-gain transistors are essential for the development of large-scale circuit integration, high-sensitivity sensors and signal amplification in sensing systems. Unfortunately, organic field-effect transistors show limited gain, usually of the order of tens, because of the large contact resistance and channel-length modulation. Here we show a new organic field-effect transistor architecture with a gain larger than 700. This is the highest gain ever reported for organic field-effect transistors. In the proposed organic field-effect transistor, the charge injection and extraction at the metal-semiconductor contacts are driven by the charge diffusion. The ideal conditions of ohmic contacts with negligible contact resistance and flat current saturation are demonstrated. The approach is general and can be extended to any thin-film technology opening unprecedented opportunities for the development of high-performance flexible electronics.

High-Performance Vertical Organic Electrochemical Transistors.

PubMed

Donahue, Mary J; Williamson, Adam; Strakosas, Xenofon; Friedlein, Jacob T; McLeod, Robert R; Gleskova, Helena; Malliaras, George G

2018-02-01

Organic electrochemical transistors (OECTs) are promising transducers for biointerfacing due to their high transconductance, biocompatibility, and availability in a variety of form factors. Most OECTs reported to date, however, utilize rather large channels, limiting the transistor performance and resulting in a low transistor density. This is typically a consequence of limitations associated with traditional fabrication methods and with 2D substrates. Here, the fabrication and characterization of OECTs with vertically stacked contacts, which overcome these limitations, is reported. The resulting vertical transistors exhibit a reduced footprint, increased intrinsic transconductance of up to 57 mS, and a geometry-normalized transconductance of 814 S m -1 . The fabrication process is straightforward and compatible with sensitive organic materials, and allows exceptional control over the transistor channel length. This novel 3D fabrication method is particularly suited for applications where high density is needed, such as in implantable devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Validation of behave fire behavior predictions in oak savannas

USGS Publications Warehouse

Grabner, Keith W.; Dwyer, John; Cutter, Bruce E.

1997-01-01

Prescribed fire is a valuable tool in the restoration and management of oak savannas. BEHAVE, a fire behavior prediction system developed by the United States Forest Service, can be a useful tool when managing oak savannas with prescribed fire. BEHAVE predictions of fire rate-of-spread and flame length were validated using four standardized fuel models: Fuel Model 1 (short grass), Fuel Model 2 (timber and grass), Fuel Model 3 (tall grass), and Fuel Model 9 (hardwood litter). Also, a customized oak savanna fuel model (COSFM) was created and validated. Results indicate that standardized fuel model 2 and the COSFM reliably estimate mean rate-of-spread (MROS). The COSFM did not appreciably reduce MROS variation when compared to fuel model 2. Fuel models 1, 3, and 9 did not reliably predict MROS. Neither the standardized fuel models nor the COSFM adequately predicted flame lengths. We concluded that standardized fuel model 2 should be used with BEHAVE when predicting fire rates-of-spread in established oak savannas.

Ambipolar nonvolatile memory based on a quantum-dot transistor with a nanoscale floating gate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Che, Yongli; Zhang, Yating, E-mail: yating@tju.edu.cn; Song, Xiaoxian

2016-07-04

Using only solution processing methods, we developed ambipolar quantum-dot (QD) transistor floating-gate memory (FGM) that uses Au nanoparticles as a floating gate. Because of the bipolarity of the active channel of PbSe QDs, the memory could easily trap holes or electrons in the floating gate by programming/erasing (P/E) operations, which could shift the threshold voltage both up and down. As a result, the memory exhibited good programmable memory characteristics: a large memory window (ΔV{sub th} ∼ 15 V) and a long retention time (>10{sup 5 }s). The magnitude of ΔV{sub th} depended on both P/E voltages and the bias voltage (V{sub DS}): ΔV{sub th}more » was a cubic function to V{sub P/E} and linearly depended on V{sub DS}. Therefore, this FGM based on a QD transistor is a promising alternative to its inorganic counterparts owing to its advantages of bipolarity, high mobility, low cost, and large-area production.« less

High transconductance organic electrochemical transistors

NASA Astrophysics Data System (ADS)

Khodagholy, Dion; Rivnay, Jonathan; Sessolo, Michele; Gurfinkel, Moshe; Leleux, Pierre; Jimison, Leslie H.; Stavrinidou, Eleni; Herve, Thierry; Sanaur, Sébastien; Owens, Róisín M.; Malliaras, George G.

2013-07-01

The development of transistors with high gain is essential for applications ranging from switching elements and drivers to transducers for chemical and biological sensing. Organic transistors have become well-established based on their distinct advantages, including ease of fabrication, synthetic freedom for chemical functionalization, and the ability to take on unique form factors. These devices, however, are largely viewed as belonging to the low-end of the performance spectrum. Here we present organic electrochemical transistors with a transconductance in the mS range, outperforming transistors from both traditional and emerging semiconductors. The transconductance of these devices remains fairly constant from DC up to a frequency of the order of 1 kHz, a value determined by the process of ion transport between the electrolyte and the channel. These devices, which continue to work even after being crumpled, are predicted to be highly relevant as transducers in biosensing applications.

High transconductance organic electrochemical transistors

PubMed Central

Khodagholy, Dion; Rivnay, Jonathan; Sessolo, Michele; Gurfinkel, Moshe; Leleux, Pierre; Jimison, Leslie H.; Stavrinidou, Eleni; Herve, Thierry; Sanaur, Sébastien; Owens, Róisín M.; Malliaras, George G.

2013-01-01

The development of transistors with high gain is essential for applications ranging from switching elements and drivers to transducers for chemical and biological sensing. Organic transistors have become well-established based on their distinct advantages, including ease of fabrication, synthetic freedom for chemical functionalization, and the ability to take on unique form factors. These devices, however, are largely viewed as belonging to the low-end of the performance spectrum. Here we present organic electrochemical transistors with a transconductance in the mS range, outperforming transistors from both traditional and emerging semiconductors. The transconductance of these devices remains fairly constant from DC up to a frequency of the order of 1 kHz, a value determined by the process of ion transport between the electrolyte and the channel. These devices, which continue to work even after being crumpled, are predicted to be highly relevant as transducers in biosensing applications. PMID:23851620

Magnetic properties of superparamagnetic β-NaFeO2 nanoparticles

NASA Astrophysics Data System (ADS)

Singh, Sarbjit; Tovstolytkin, Alexandr; Lotey, Gurmeet Singh

2018-07-01

Superparamagnetic β-NaFeO2 nanoparticles of particle size 37 nm with orthorhombic crystal structure and space group Pn21a have been prepared by sol-gel method. Temperature dependent magnetic study has been performed. Its systematic analysis has been done to calculate the Curie and blocking temperatures along with its magnetic susceptibility. The Langevin fitting of the magnetic data has been carried out. It has been shown that the synthesized nanoparticles exhibit superparamagnetic behavior. The Neel's relaxation time has been calculated to further support its superparamagnetic nature. The synthesized β-NaFeO2 nanoparticles behave like ferromagnets below 80 K; they are superparamagnetic above 80 K-340 K and thereafter as paramagnetic. The possible mechanism of superparamagnetism has been discussed. It has been concluded that these nanoparticles can find wide applications in the area of biomedical sciences.

Recent progress in photoactive organic field-effect transistors.

PubMed

Wakayama, Yutaka; Hayakawa, Ryoma; Seo, Hoon-Seok

2014-04-01

Recent progress in photoactive organic field-effect transistors (OFETs) is reviewed. Photoactive OFETs are divided into light-emitting (LE) and light-receiving (LR) OFETs. In the first part, LE-OFETs are reviewed from the viewpoint of the evolution of device structures. Device performances have improved in the last decade with the evolution of device structures from single-layer unipolar to multi-layer ambipolar transistors. In the second part, various kinds of LR-OFETs are featured. These are categorized according to their functionalities: phototransistors, non-volatile optical memories, and photochromism-based transistors. For both, various device configurations are introduced: thin-film based transistors for practical applications, single-crystalline transistors to investigate fundamental physics, nanowires, multi-layers, and vertical transistors based on new concepts.

Fuel model selection for BEHAVE in midwestern oak savannas

USGS Publications Warehouse

Grabner, K.W.; Dwyer, J.P.; Cutter, B.E.

2001-01-01

BEHAVE, a fire behavior prediction system, can be a useful tool for managing areas with prescribed fire. However, the proper choice of fuel models can be critical in developing management scenarios. BEHAVE predictions were evaluated using four standardized fuel models that partially described oak savanna fuel conditions: Fuel Model 1 (Short Grass), 2 (Timber and Grass), 3 (Tall Grass), and 9 (Hardwood Litter). Although all four models yielded regressions with R2 in excess of 0.8, Fuel Model 2 produced the most reliable fire behavior predictions.

High-Speed, high-power, switching transistor

NASA Technical Reports Server (NTRS)

Carnahan, D.; Ohu, C. K.; Hower, P. L.

1979-01-01

Silicon transistor rate for 200 angstroms at 400 to 600 volts combines switching speed of transistors with ruggedness, power capacity of thyristor. Transistor introduces unique combination of increased power-handling capability, unusally low saturation and switching losses, and submicrosecond switching speeds. Potential applications include high power switching regulators, linear amplifiers, chopper controls for high frequency electrical vehicle drives, VLF transmitters, RF induction heaters, kitchen cooking ranges, and electronic scalpels for medical surgery.

Universal power transistor base drive control unit

DOEpatents

Gale, Allan R.; Gritter, David J.

1988-01-01

A saturation condition regulator system for a power transistor which achieves the regulation objectives of a Baker clamp but without dumping excess base drive current into the transistor output circuit. The base drive current of the transistor is sensed and used through an active feedback circuit to produce an error signal which modulates the base drive current through a linearly operating FET. The collector base voltage of the power transistor is independently monitored to develop a second error signal which is also used to regulate base drive current. The current-sensitive circuit operates as a limiter. In addition, a fail-safe timing circuit is disclosed which automatically resets to a turn OFF condition in the event the transistor does not turn ON within a predetermined time after the input signal transition.

Universal power transistor base drive control unit

DOEpatents

Gale, A.R.; Gritter, D.J.

1988-06-07

A saturation condition regulator system for a power transistor is disclosed which achieves the regulation objectives of a Baker clamp but without dumping excess base drive current into the transistor output circuit. The base drive current of the transistor is sensed and used through an active feedback circuit to produce an error signal which modulates the base drive current through a linearly operating FET. The collector base voltage of the power transistor is independently monitored to develop a second error signal which is also used to regulate base drive current. The current-sensitive circuit operates as a limiter. In addition, a fail-safe timing circuit is disclosed which automatically resets to a turn OFF condition in the event the transistor does not turn ON within a predetermined time after the input signal transition. 2 figs.

Electron and hole transport in ambipolar, thin film pentacene transistors

NASA Astrophysics Data System (ADS)

Saudari, Sangameshwar R.; Kagan, Cherie R.

2015-01-01

Solution-processed, ambipolar, thin-film pentacene field-effect transistors were employed to study both electron and hole transport simultaneously in a single, organic solid-state device. Electron and hole mobilities were extracted from the respective unipolar saturation regimes and show thermally activated behavior and gate voltage dependence. We fit the gate voltage dependent saturation mobility to a power law to extract the characteristic Meyer-Neldel (MN) energy, a measure of the width of the exponential distribution of localized states extending into the energy gap of the organic semiconductor. The MN energy is ˜78 and ˜28 meV for electrons and holes, respectively, which reflects a greater density of localized tail states for electrons than holes. This is consistent with the lower measured electron than hole mobility. For holes, the well-behaved linear regime allows for four-point probe measurement of the contact resistance independent mobility and separate characterization of the width of the localized density of states, yielding a consistent MN energy of 28 meV.

Structural and optical properties of novel surfactant-coated Yb@TiO2 nanoparticles

NASA Astrophysics Data System (ADS)

Calandra, P.; Lombardo, D.; Pistone, A.; Turco Liveri, V.; Trusso, S.

2011-11-01

In this paper a novel hybrid approach to synthesise composite nanoparticles is presented. It is based on the laser ablation of a bulk target (Yb) immersed in a reversed micellar solution which contains nanoparticles of a different host material (TiO2 nanoparticles) previously synthesised by chemical method. This approach thus exploits the advantages of the chemical synthesis through reversed micellar solution (size control, nanoparticle stabilisation), and of the laser ablation ("clean" synthesis, no side reactions). Central role is played by the microscopic processes controlling the deposition of the ablated Yb atoms onto the surface of TiO2 nanoparticles which actually behave as nucleation seeds. The structural features of the resulting Yb@TiO2 composite nanoparticles have been studied by Transmission Electron Microscopy, whereas their peculiar optical properties have been explored by UV-Vis spectroscopy and steady-state fluorescence. Results consistently show the formation of Yb and TiO2 glued nanodomains to form nearly spherical and non-interacting nanoparticles with enhanced photophysical properties.

Atomic layer deposition of insulating nitride interfacial layers for germanium metal oxide semiconductor field effect transistors with high-κ oxide/tungsten nitride gate stacks

NASA Astrophysics Data System (ADS)

Kim, Kyoung H.; Gordon, Roy G.; Ritenour, Andrew; Antoniadis, Dimitri A.

2007-05-01

Atomic layer deposition (ALD) was used to deposit passivating interfacial nitride layers between Ge and high-κ oxides. High-κ oxides on Ge surfaces passivated by ultrathin (1-2nm) ALD Hf3N4 or AlN layers exhibited well-behaved C-V characteristics with an equivalent oxide thickness as low as 0.8nm, no significant flatband voltage shifts, and midgap density of interface states values of 2×1012cm-1eV-1. Functional n-channel and p-channel Ge field effect transistors with nitride interlayer/high-κ oxide/metal gate stacks are demonstrated.

Hafnium transistor design for neural interfacing.

PubMed

Parent, David W; Basham, Eric J

2008-01-01

A design methodology is presented that uses the EKV model and the g(m)/I(D) biasing technique to design hafnium oxide field effect transistors that are suitable for neural recording circuitry. The DC gain of a common source amplifier is correlated to the structural properties of a Field Effect Transistor (FET) and a Metal Insulator Semiconductor (MIS) capacitor. This approach allows a transistor designer to use a design flow that starts with simple and intuitive 1-D equations for gain that can be verified in 1-D MIS capacitor TCAD simulations, before final TCAD process verification of transistor properties. The DC gain of a common source amplifier is optimized by using fast 1-D simulations and using slower, complex 2-D simulations only for verification. The 1-D equations are used to show that the increased dielectric constant of hafnium oxide allows a higher DC gain for a given oxide thickness. An additional benefit is that the MIS capacitor can be employed to test additional performance parameters important to an open gate transistor such as dielectric stability and ionic penetration.

Self-Enhancing in Perceptions of Behaving Unethically.

ERIC Educational Resources Information Center

Manley, Gregory G.; Russell, Craig J.; Buckley, M. Ronald

2001-01-01

Presented with ethics scenarios, the majority of 43 accounting and 43 marketing majors perceived themselves less likely to behave unethically than others would. Marketing majors showed significantly higher levels of self-enhancement bias, a difference that decreased as perceived risk increased. (SK)

Chemically assembled double-dot single-electron transistor analyzed by the orthodox model considering offset charge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kano, Shinya; Maeda, Kosuke; Majima, Yutaka, E-mail: majima@msl.titech.ac.jp

2015-10-07

We present the analysis of chemically assembled double-dot single-electron transistors using orthodox model considering offset charges. First, we fabricate chemically assembled single-electron transistors (SETs) consisting of two Au nanoparticles between electroless Au-plated nanogap electrodes. Then, extraordinary stable Coulomb diamonds in the double-dot SETs are analyzed using the orthodox model, by considering offset charges on the respective quantum dots. We determine the equivalent circuit parameters from Coulomb diamonds and drain current vs. drain voltage curves of the SETs. The accuracies of the capacitances and offset charges on the quantum dots are within ±10%, and ±0.04e (where e is the elementary charge),more » respectively. The parameters can be explained by the geometrical structures of the SETs observed using scanning electron microscopy images. Using this approach, we are able to understand the spatial characteristics of the double quantum dots, such as the relative distance from the gate electrode and the conditions for adsorption between the nanogap electrodes.« less

Low-voltage all-inorganic perovskite quantum dot transistor memory

NASA Astrophysics Data System (ADS)

Chen, Zhiliang; Zhang, Yating; Zhang, Heng; Yu, Yu; Song, Xiaoxian; Zhang, Haiting; Cao, Mingxuan; Che, Yongli; Jin, Lufan; Li, Yifan; Li, Qingyan; Dai, Haitao; Yang, Junbo; Yao, Jianquan

2018-05-01

An all-inorganic cesium lead halide quantum dot (QD) based Au nanoparticle (NP) floating-gate memory with a solution processed layer-by-layer method is demonstrated. Easy synthesis at room temperature and excellent stability make all-inorganic CsPbBr3 perovskite QDs suitable as a semiconductor layer in low voltage nonvolatile transistor memory. The bipolarity of QDs has both electrons and holes stored in the Au NP floating gate, resulting in bidirectional shifts of initial threshold voltage according to the applied programing and erasing pulses. Under low operation voltage (±5 V), the memory achieved a great memory window (˜2.4 V), long retention time (>105 s), and stable endurance properties after 200 cycles. So the proposed memory device based on CsPbBr3 perovskite QDs has a great potential in the flash memory market.

Surface patterning of nanoparticles with polymer patches

NASA Astrophysics Data System (ADS)

Choueiri, Rachelle M.; Galati, Elizabeth; Thérien-Aubin, Héloïse; Klinkova, Anna; Larin, Egor M.; Querejeta-Fernández, Ana; Han, Lili; Xin, Huolin L.; Gang, Oleg; Zhulina, Ekaterina B.; Rubinstein, Michael; Kumacheva, Eugenia

2016-10-01

Patterning of colloidal particles with chemically or topographically distinct surface domains (patches) has attracted intense research interest. Surface-patterned particles act as colloidal analogues of atoms and molecules, serve as model systems in studies of phase transitions in liquid systems, behave as ‘colloidal surfactants’ and function as templates for the synthesis of hybrid particles. The generation of micrometre- and submicrometre-sized patchy colloids is now efficient, but surface patterning of inorganic colloidal nanoparticles with dimensions of the order of tens of nanometres is uncommon. Such nanoparticles exhibit size- and shape-dependent optical, electronic and magnetic properties, and their assemblies show new collective properties. At present, nanoparticle patterning is limited to the generation of two-patch nanoparticles, and nanoparticles with surface ripples or a ‘raspberry’ surface morphology. Here we demonstrate nanoparticle surface patterning, which utilizes thermodynamically driven segregation of polymer ligands from a uniform polymer brush into surface-pinned micelles following a change in solvent quality. Patch formation is reversible but can be permanently preserved using a photocrosslinking step. The methodology offers the ability to control the dimensions of patches, their spatial distribution and the number of patches per nanoparticle, in agreement with a theoretical model. The versatility of the strategy is demonstrated by patterning nanoparticles with different dimensions, shapes and compositions, tethered with various types of polymers and subjected to different external stimuli. These patchy nanocolloids have potential applications in fundamental research, the self-assembly of nanomaterials, diagnostics, sensing and colloidal stabilization.

Planar-Processed Polymer Transistors.

PubMed

Xu, Yong; Sun, Huabin; Shin, Eul-Yong; Lin, Yen-Fu; Li, Wenwu; Noh, Yong-Young

2016-10-01

Planar-processed polymer transistors are proposed where the effective charge injection and the split unipolar charge transport are all on the top surface of the polymer film, showing ideal device characteristics with unparalleled performance. This technique provides a great solution to the problem of fabrication limitations, the ambiguous operating principle, and the performance improvements in practical applications of conjugated-polymer transistors. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fully Printed Stretchable Thin-Film Transistors and Integrated Logic Circuits.

PubMed

Cai, Le; Zhang, Suoming; Miao, Jinshui; Yu, Zhibin; Wang, Chuan

2016-12-27

This paper reports intrinsically stretchable thin-film transistors (TFTs) and integrated logic circuits directly printed on elastomeric polydimethylsiloxane (PDMS) substrates. The printed devices utilize carbon nanotubes and a type of hybrid gate dielectric comprising PDMS and barium titanate (BaTiO 3 ) nanoparticles. The BaTiO 3 /PDMS composite simultaneously provides high dielectric constant, superior stretchability, low leakage, as well as good printability and compatibility with the elastomeric substrate. Both TFTs and logic circuits can be stretched beyond 50% strain along either channel length or channel width directions for thousands of cycles while showing no significant degradation in electrical performance. This work may offer an entry into more sophisticated stretchable electronic systems with monolithically integrated sensors, actuators, and displays, fabricated by scalable and low-cost methods for real life applications.

Graphene-based flexible and stretchable thin film transistors.

PubMed

Yan, Chao; Cho, Jeong Ho; Ahn, Jong-Hyun

2012-08-21

Graphene has been attracting wide attention owing to its superb electronic, thermal and mechanical properties. These properties allow great applications in the next generation of optoelectronics, where flexibility and stretchability are essential. In this context, the recent development of graphene growth/transfer and its applications in field-effect transistors are involved. In particular, we provide a detailed review on the state-of-the-art of graphene-based flexible and stretchable thin film transistors. We address the principles of fabricating high-speed graphene analog transistors and the key issues of producing an array of graphene-based transistors on flexible and stretchable substrates. It provides a platform for future work to focus on understanding and realizing high-performance graphene-based transistors.

Coaxial inverted geometry transistor having buried emitter

NASA Technical Reports Server (NTRS)

Hruby, R. J.; Cress, S. B.; Dunn, W. R. (Inventor)

1973-01-01

The invention relates to an inverted geometry transistor wherein the emitter is buried within the substrate. The transistor can be fabricated as a part of a monolithic integrated circuit and is particularly suited for use in applications where it is desired to employ low actuating voltages. The transistor may employ the same doping levels in the collector and emitter, so these connections can be reversed.

Highly Crumpled All-Carbon Transistors for Brain Activity Recording.

PubMed

Yang, Long; Zhao, Yan; Xu, Wenjing; Shi, Enzheng; Wei, Wenjing; Li, Xinming; Cao, Anyuan; Cao, Yanping; Fang, Ying

2017-01-11

Neural probes based on graphene field-effect transistors have been demonstrated. Yet, the minimum detectable signal of graphene transistor-based probes is inversely proportional to the square root of the active graphene area. This fundamentally limits the scaling of graphene transistor-based neural probes for improved spatial resolution in brain activity recording. Here, we address this challenge using highly crumpled all-carbon transistors formed by compressing down to 16% of its initial area. All-carbon transistors, chemically synthesized by seamless integration of graphene channels and hybrid graphene/carbon nanotube electrodes, maintained structural integrity and stable electronic properties under large mechanical deformation, whereas stress-induced cracking and junction failure occurred in conventional graphene/metal transistors. Flexible, highly crumpled all-carbon transistors were further verified for in vivo recording of brain activity in rats. These results highlight the importance of advanced material and device design concepts to make improvements in neuroelectronics.

High Accuracy Transistor Compact Model Calibrations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hembree, Charles E.; Mar, Alan; Robertson, Perry J.

2015-09-01

Typically, transistors are modeled by the application of calibrated nominal and range models. These models consists of differing parameter values that describe the location and the upper and lower limits of a distribution of some transistor characteristic such as current capacity. Correspond- ingly, when using this approach, high degrees of accuracy of the transistor models are not expected since the set of models is a surrogate for a statistical description of the devices. The use of these types of models describes expected performances considering the extremes of process or transistor deviations. In contrast, circuits that have very stringent accuracy requirementsmore » require modeling techniques with higher accuracy. Since these accurate models have low error in transistor descriptions, these models can be used to describe part to part variations as well as an accurate description of a single circuit instance. Thus, models that meet these stipulations also enable the calculation of quantifi- cation of margins with respect to a functional threshold and uncertainties in these margins. Given this need, new model high accuracy calibration techniques for bipolar junction transis- tors have been developed and are described in this report.« less

A transistor based on 2D material and silicon junction

NASA Astrophysics Data System (ADS)

Kim, Sanghoek; Lee, Seunghyun

2017-07-01

A new type of graphene-silicon junction transistor based on bipolar charge-carrier injection was designed and investigated. In contrast to many recent studies on graphene field-effect transistor (FET), this device is a new type of bipolar junction transistor (BJT). The transistor fully utilizes the Fermi level tunability of graphene under bias to increase the minority-carrier injection efficiency of the base-emitter junction in the BJT. Single-layer graphene was used to form the emitter and the collector, and a p-type silicon was used as the base. The output of this transistor was compared with a metal-silicon junction transistor ( i.e. surface-barrier transistor) to understand the difference between a graphene-silicon junction and metal-silicon Schottky junction. A significantly higher current gain was observed in the graphene-silicon junction transistor as the base current was increased. The graphene-semiconductor heterojunction transistor offers several unique advantages, such as an extremely thin device profile, a low-temperature (< 110 °C) fabrication process, low cost (no furnace process), and high-temperature tolerance due to graphene's stability. A transistor current gain ( β) of 33.7 and a common-emitter amplifier voltage gain of 24.9 were achieved.

Coupling between electrolyte and organic semiconductor in electrolyte-gated organic field effect transistors (Conference Presentation)

NASA Astrophysics Data System (ADS)

Biscarini, Fabio; Di Lauro, Michele; Berto, Marcello; Bortolotti, Carlo A.; Geerts, Yves H.; Vuillaume, Dominique

2016-11-01

Organic field effect transistors (OFET) operated in aqueous environments are emerging as ultra-sensitive biosensors and transducers of electrical and electrochemical signals from a biological environment. Their applications range from detection of biomarkers in bodily fluids to implants for bidirectional communication with the central nervous system. They can be used in diagnostics, advanced treatments and theranostics. Several OFET layouts have been demonstrated to be effective in aqueous operations, which are distinguished either by their architecture or by the respective mechanism of doping by the ions in the electrolyte solution. In this work we discuss the unification of the seemingly different architectures, such as electrolyte-gated OFET (EGOFET), organic electrochemical transistor (OECT) and dual-gate ion-sensing FET. We first demonstrate that these architectures give rise to the frequency-dependent response of a synapstor (synapse-like transistor), with enhanced or depressed modulation of the output current depending on the frequency of the time-dependent gate voltage. This behavior that was reported for OFETs with embedded metal nanoparticles shows the existence of a capacitive coupling through an equivalent network of RC elements. Upon the systematic change of ions in the electrolyte and the morphology of the charge transport layer, we show how the time scale of the synapstor is changed. We finally show how the substrate plays effectively the role of a second bottom gate, whose potential is actually fixed by the pH/composition of the electrolyte and the gate voltage applied.

Responsiveness in Behaving Monkeys and Human Subjects

DTIC Science & Technology

1993-07-31

Status of Current Research - Statement of Work Each study involving awake , behaving monkey neurophysiological recording used a behavioral paradigm that...anesthesia. A craniotomy was performed at approximately A+ 14.5mm. The recording chamber then was fixed to the skull at a lateral angle of 8’ from

Multiple-channel detection of cellular activities by ion-sensitive transistors

NASA Astrophysics Data System (ADS)

Machida, Satoru; Shimada, Hideto; Motoyama, Yumi

2018-04-01

An ion-sensitive field-effect transistor to record cellular activities was demonstrated. This field-effect transistor (bio transistor) includes cultured cells on the gate insulator instead of gate electrode. The bio transistor converts a change in potential underneath the cells into variation of the drain current when ion channels open. The bio transistor has high detection sensitivity to even minute variations in potential utilizing a subthreshold swing region. To open ion channels, a reagent solution (acetylcholine) was added to a human-originating cell cultured on the bio transistor. The drain current was successfully decreased with the addition of acetylcholine. Moreover, we attempted to detect the opening of ion channels using a multiple-channel measurement circuit containing several bio transistors. As a consequence, the drain current distinctly decreased only after the addition of acetylcholine. We confirmed that this measurement system including bio transistors enables to observation of cellular activities sensitively and simultaneously.

Cellular Level Brain Imaging in Behaving Mammals: An Engineering Approach

PubMed Central

Hamel, Elizabeth J.O.; Grewe, Benjamin F.; Parker, Jones G.; Schnitzer, Mark J.

2017-01-01

Fluorescence imaging offers expanding capabilities for recording neural dynamics in behaving mammals, including the means to monitor hundreds of cells targeted by genetic type or connectivity, track cells over weeks, densely sample neurons within local microcircuits, study cells too inactive to isolate in extracellular electrical recordings, and visualize activity in dendrites, axons, or dendritic spines. We discuss recent progress and future directions for imaging in behaving mammals from a systems engineering perspective, which seeks holistic consideration of fluorescent indicators, optical instrumentation, and computational analyses. Today, genetically encoded indicators of neural Ca2+ dynamics are widely used, and those of trans-membrane voltage are rapidly improving. Two complementary imaging paradigms involve conventional microscopes for studying head-restrained animals and head-mounted miniature microscopes for imaging in freely behaving animals. Overall, the field has attained sufficient sophistication that increased cooperation between those designing new indicators, light sources, microscopes, and computational analyses would greatly benefit future progress. PMID:25856491

Multimode Silicon Nanowire Transistors

PubMed Central

2014-01-01

The combined capabilities of both a nonplanar design and nonconventional carrier injection mechanisms are subject to recent scientific investigations to overcome the limitations of silicon metal oxide semiconductor field effect transistors. In this Letter, we present a multimode field effect transistors device using silicon nanowires that feature an axial n-type/intrinsic doping junction. A heterostructural device design is achieved by employing a self-aligned nickel-silicide source contact. The polymorph operation of the dual-gate device enabling the configuration of one p- and two n-type transistor modes is demonstrated. Not only the type but also the carrier injection mode can be altered by appropriate biasing of the two gate terminals or by inverting the drain bias. With a combined band-to-band and Schottky tunneling mechanism, in p-type mode a subthreshold swing as low as 143 mV/dec and an ON/OFF ratio of up to 104 is found. As the device operates in forward bias, a nonconventional tunneling transistor is realized, enabling an effective suppression of ambipolarity. Depending on the drain bias, two different n-type modes are distinguishable. The carrier injection is dominated by thermionic emission in forward bias with a maximum ON/OFF ratio of up to 107 whereas in reverse bias a Schottky tunneling mechanism dominates the carrier transport. PMID:25303290

Self-protecting transistor oscillator for treating animal tissues

DOEpatents

Doss, James D.

1980-01-01

A transistor oscillator circuit wherein the load current applied to animal tissue treatment electrodes is fed back to the transistor. Removal of load is sensed to automatically remove feedback and stop oscillations. A thermistor on one treatment electrode senses temperature, and by means of a control circuit controls oscillator transistor current.

Doped organic transistors operating in the inversion and depletion regime

PubMed Central

Lüssem, Björn; Tietze, Max L.; Kleemann, Hans; Hoßbach, Christoph; Bartha, Johann W.; Zakhidov, Alexander; Leo, Karl

2013-01-01

The inversion field-effect transistor is the basic device of modern microelectronics and is nowadays used more than a billion times on every state-of-the-art computer chip. In the future, this rigid technology will be complemented by flexible electronics produced at extremely low cost. Organic field-effect transistors have the potential to be the basic device for flexible electronics, but still need much improvement. In particular, despite more than 20 years of research, organic inversion mode transistors have not been reported so far. Here we discuss the first realization of organic inversion transistors and the optimization of organic depletion transistors by our organic doping technology. We show that the transistor parameters—in particular, the threshold voltage and the ON/OFF ratio—can be controlled by the doping concentration and the thickness of the transistor channel. Injection of minority carriers into the doped transistor channel is achieved by doped contacts, which allows forming an inversion layer. PMID:24225722

Design considerations for FET-gated power transistors

NASA Technical Reports Server (NTRS)

Chen, D. Y.; Chin, S. A.

1983-01-01

An FET-bipolar combinational power transistor configuration (tested up to 300 V, 20 A at 100 kHz) is described. The critical parameters for integrating the chips in hybrid form are examined, and an effort to optimize the overall characteristics of the configuration is discussed. Chip considerations are examined with respect to the voltage and current rating of individual chips, the FET surge capability, the choice of triple diffused transistor or epitaxial transistor for the bipolar element, the current tailing effect, and the implementation of the bipolar transistor and an FET as single chip or separate chips. Package considerations are discussed with respect to package material and geometry, surge current capability of bipolar base terminal bonding, and power losses distribution.

CMOS-based carbon nanotube pass-transistor logic integrated circuits

PubMed Central

Ding, Li; Zhang, Zhiyong; Liang, Shibo; Pei, Tian; Wang, Sheng; Li, Yan; Zhou, Weiwei; Liu, Jie; Peng, Lian-Mao

2012-01-01

Field-effect transistors based on carbon nanotubes have been shown to be faster and less energy consuming than their silicon counterparts. However, ensuring these advantages are maintained for integrated circuits is a challenge. Here we demonstrate that a significant reduction in the use of field-effect transistors can be achieved by constructing carbon nanotube-based integrated circuits based on a pass-transistor logic configuration, rather than a complementary metal-oxide semiconductor configuration. Logic gates are constructed on individual carbon nanotubes via a doping-free approach and with a single power supply at voltages as low as 0.4 V. The pass-transistor logic configurarion provides a significant simplification of the carbon nanotube-based circuit design, a higher potential circuit speed and a significant reduction in power consumption. In particular, a full adder, which requires a total of 28 field-effect transistors to construct in the usual complementary metal-oxide semiconductor circuit, uses only three pairs of n- and p-field-effect transistors in the pass-transistor logic configuration. PMID:22334080

Surface patterning of nanoparticles with polymer patches

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choueiri, Rachelle M.; Galati, Elizabeth; Thérien-Aubin, Héloïse

Patterning of colloidal particles with chemically or topographically distinct surface domains (patches) has attracted intense research interest. Surface-patterned particles act as colloidal analogues of atoms and molecules serve as model systems in studies of phase transitions in liquid systems, behave as ‘colloidal surfactants’ and function as templates for the synthesis of hybrid particles. The generation of micrometre- and submicrometre-sized patchy colloids is now efficient but surface patterning of inorganic colloidal nanoparticles with dimensions of the order of tens of nanometres is uncommon. Such nanoparticles exhibit size- and shape-dependent optical, electronic and magnetic properties, and their assemblies show new collective properties.more » At present, nanoparticle patterning is limited to the generation of two-patch nanoparticles and nanoparticles with surface ripples or a ‘raspberry’ surface morphology. We demonstrate nanoparticle surface patterning, which utilizes thermodynamically driven segregation of polymer ligands from a uniform polymer brush into surface-pinned micelles following a change in solvent quality. Patch formation is reversible but can be permanently preserved using a photocrosslinking step. The methodology offers the ability to control the dimensions of patches, their spatial distribution and the number of patches per nanoparticle, in agreement with a theoretical model. The versatility of the strategy is demonstrated by patterning nanoparticles with different dimensions, shapes and compositions, tethered with various types of polymers and subjected to different external stimuli. Furthermore, these patchy nanocolloids have potential applications in fundamental research, the self-assembly of nanomaterials, diagnostics, sensing and colloidal stabilization.« less

Surface patterning of nanoparticles with polymer patches

DOE PAGES

Choueiri, Rachelle M.; Galati, Elizabeth; Thérien-Aubin, Héloïse; ...

2016-08-24

Patterning of colloidal particles with chemically or topographically distinct surface domains (patches) has attracted intense research interest. Surface-patterned particles act as colloidal analogues of atoms and molecules serve as model systems in studies of phase transitions in liquid systems, behave as ‘colloidal surfactants’ and function as templates for the synthesis of hybrid particles. The generation of micrometre- and submicrometre-sized patchy colloids is now efficient but surface patterning of inorganic colloidal nanoparticles with dimensions of the order of tens of nanometres is uncommon. Such nanoparticles exhibit size- and shape-dependent optical, electronic and magnetic properties, and their assemblies show new collective properties.more » At present, nanoparticle patterning is limited to the generation of two-patch nanoparticles and nanoparticles with surface ripples or a ‘raspberry’ surface morphology. We demonstrate nanoparticle surface patterning, which utilizes thermodynamically driven segregation of polymer ligands from a uniform polymer brush into surface-pinned micelles following a change in solvent quality. Patch formation is reversible but can be permanently preserved using a photocrosslinking step. The methodology offers the ability to control the dimensions of patches, their spatial distribution and the number of patches per nanoparticle, in agreement with a theoretical model. The versatility of the strategy is demonstrated by patterning nanoparticles with different dimensions, shapes and compositions, tethered with various types of polymers and subjected to different external stimuli. Furthermore, these patchy nanocolloids have potential applications in fundamental research, the self-assembly of nanomaterials, diagnostics, sensing and colloidal stabilization.« less

Triple-mode single-transistor graphene amplifier and its applications.

PubMed

Yang, Xuebei; Liu, Guanxiong; Balandin, Alexander A; Mohanram, Kartik

2010-10-26

We propose and experimentally demonstrate a triple-mode single-transistor graphene amplifier utilizing a three-terminal back-gated single-layer graphene transistor. The ambipolar nature of electronic transport in graphene transistors leads to increased amplifier functionality as compared to amplifiers built with unipolar semiconductor devices. The ambipolar graphene transistors can be configured as n-type, p-type, or hybrid-type by changing the gate bias. As a result, the single-transistor graphene amplifier can operate in the common-source, common-drain, or frequency multiplication mode, respectively. This in-field controllability of the single-transistor graphene amplifier can be used to realize the modulation necessary for phase shift keying and frequency shift keying, which are widely used in wireless applications. It also offers new opportunities for designing analog circuits with simpler structure and higher integration densities for communications applications.

Thermal transistor utilizing gas-liquid transition.

PubMed

Komatsu, Teruhisa S; Ito, Nobuyasu

2011-01-01

We propose a simple thermal transistor, a device to control heat current. In order to effectively change the current, we utilize the gas-liquid transition of the heat-conducting medium (fluid) because the gas region can act as a good thermal insulator. The three terminals of the transistor are located at both ends and the center of the system, and are put into contact with distinct heat baths. The key idea is a special arrangement of the three terminals. The temperature at one end (the gate temperature) is used as an input signal to control the heat current between the center (source, hot) and another end (drain, cold). Simulating the nanoscale systems of this transistor, control of heat current is demonstrated. The heat current is effectively cut off when the gate temperature is cold and it flows normally when it is hot. By using an extended version of this transistor, we also simulate a primitive application for an inverter.

Water-gel for gating graphene transistors.

PubMed

Kim, Beom Joon; Um, Soong Ho; Song, Woo Chul; Kim, Yong Ho; Kang, Moon Sung; Cho, Jeong Ho

2014-05-14

Water, the primary electrolyte in biology, attracts significant interest as an electrolyte-type dielectric material for transistors compatible with biological systems. Unfortunately, the fluidic nature and low ionic conductivity of water prevents its practical usage in such applications. Here, we describe the development of a solid state, megahertz-operating, water-based gate dielectric system for operating graphene transistors. The new electrolyte systems were prepared by dissolving metal-substituted DNA polyelectrolytes into water. The addition of these biocompatible polyelectrolytes induced hydrogelation to provide solid-state integrity to the system. They also enhanced the ionic conductivities of the electrolytes, which in turn led to the quick formation of an electric double layer at the graphene/electrolyte interface that is beneficial for modulating currents in graphene transistors at high frequencies. At the optimized conditions, the Na-DNA water-gel-gated flexible transistors and inverters were operated at frequencies above 1 MHz and 100 kHz, respectively.

Current status and future needs of the BehavePlus Fire Modeling System

Treesearch

Patricia L. Andrews

2014-01-01

The BehavePlus Fire Modeling System is among the most widely used systems for wildland fire prediction. It is designed for use in a range of tasks including wildfire behaviour prediction, prescribed fire planning, fire investigation, fuel hazard assessment, fire model understanding, communication and research. BehavePlus is based on mathematical models for fire...

Field effect transistors improve buffer amplifier

NASA Technical Reports Server (NTRS)

1967-01-01

Unity gain buffer amplifier with a Field Effect Transistor /FET/ differential input stage responds much faster than bipolar transistors when operated at low current levels. The circuit uses a dual FET in a unity gain buffer amplifier having extremely high input impedance, low bias current requirements, and wide bandwidth.

Age differences in how consumers behave following exposure to DTC advertising.

PubMed

DeLorme, Denise E; Huh, Jisu; Reid, Leonard N

2006-01-01

This study was conducted to provide additional evidence on how consumers behave following direct-to-consumer (DTC) advertising exposure and to determine if there are differences in ad-prompted acts (drug inquiry and drug requests) between different age groups (i.e., older, mature, and younger adults). The results suggest that younger, mature, and older consumers are all moved to act by DTC drug ads, but that each age group behaves in different ways. Somewhat surprisingly, age was not predictive of ad-prompted behavior. DTC advertising was no more effective at moving older consumers to behave than their younger counterparts. These results suggest that age does not matter that much when it comes to the "moving power" of prescription drug advertising, even though research indicates that older consumers are more vulnerable to the persuasive effects of communication.

Photon-triggered nanowire transistors

NASA Astrophysics Data System (ADS)

Kim, Jungkil; Lee, Hoo-Cheol; Kim, Kyoung-Ho; Hwang, Min-Soo; Park, Jin-Sung; Lee, Jung Min; So, Jae-Pil; Choi, Jae-Hyuck; Kwon, Soon-Hong; Barrelet, Carl J.; Park, Hong-Gyu

2017-10-01

Photon-triggered electronic circuits have been a long-standing goal of photonics. Recent demonstrations include either all-optical transistors in which photons control other photons or phototransistors with the gate response tuned or enhanced by photons. However, only a few studies report on devices in which electronic currents are optically switched and amplified without an electrical gate. Here we show photon-triggered nanowire (NW) transistors, photon-triggered NW logic gates and a single NW photodetection system. NWs are synthesized with long crystalline silicon (CSi) segments connected by short porous silicon (PSi) segments. In a fabricated device, the electrical contacts on both ends of the NW are connected to a single PSi segment in the middle. Exposing the PSi segment to light triggers a current in the NW with a high on/off ratio of >8 × 106. A device that contains two PSi segments along the NW can be triggered using two independent optical input signals. Using localized pump lasers, we demonstrate photon-triggered logic gates including AND, OR and NAND gates. A photon-triggered NW transistor of diameter 25 nm with a single 100 nm PSi segment requires less than 300 pW of power. Furthermore, we take advantage of the high photosensitivity and fabricate a submicrometre-resolution photodetection system. Photon-triggered transistors offer a new venue towards multifunctional device applications such as programmable logic elements and ultrasensitive photodetectors.

Photon-triggered nanowire transistors.

PubMed

Kim, Jungkil; Lee, Hoo-Cheol; Kim, Kyoung-Ho; Hwang, Min-Soo; Park, Jin-Sung; Lee, Jung Min; So, Jae-Pil; Choi, Jae-Hyuck; Kwon, Soon-Hong; Barrelet, Carl J; Park, Hong-Gyu

2017-10-01

Photon-triggered electronic circuits have been a long-standing goal of photonics. Recent demonstrations include either all-optical transistors in which photons control other photons or phototransistors with the gate response tuned or enhanced by photons. However, only a few studies report on devices in which electronic currents are optically switched and amplified without an electrical gate. Here we show photon-triggered nanowire (NW) transistors, photon-triggered NW logic gates and a single NW photodetection system. NWs are synthesized with long crystalline silicon (CSi) segments connected by short porous silicon (PSi) segments. In a fabricated device, the electrical contacts on both ends of the NW are connected to a single PSi segment in the middle. Exposing the PSi segment to light triggers a current in the NW with a high on/off ratio of >8 × 10 6 . A device that contains two PSi segments along the NW can be triggered using two independent optical input signals. Using localized pump lasers, we demonstrate photon-triggered logic gates including AND, OR and NAND gates. A photon-triggered NW transistor of diameter 25 nm with a single 100 nm PSi segment requires less than 300 pW of power. Furthermore, we take advantage of the high photosensitivity and fabricate a submicrometre-resolution photodetection system. Photon-triggered transistors offer a new venue towards multifunctional device applications such as programmable logic elements and ultrasensitive photodetectors.

Modeling of short channel MOS transistors

NASA Technical Reports Server (NTRS)

Lin, H. C.; Kokalis, D. P.; Bandy, W. R.

1976-01-01

Higher frequency response in MOS technology can be obtained by shortening the channel length. One approach for doing this involves an employment of higher resolution lithography technology. A second approach makes use of a double-diffused MOS transistor (DMOS). It is pointed out that the ordinary method of modeling the transistors used in both approaches is not accurate. An investigation is conducted of the questions which have to be considered for DMOS modeling. The modeling of a short channel MOS transistor is discussed, taking into account the derivation of the threshold voltage equation. Excellent agreement between theoretical and experimental data shows the accuracy of the described modeling approach.

Pass-transistor very large scale integration

NASA Technical Reports Server (NTRS)

Maki, Gary K. (Inventor); Bhatia, Prakash R. (Inventor)

2004-01-01

Logic elements are provided that permit reductions in layout size and avoidance of hazards. Such logic elements may be included in libraries of logic cells. A logical function to be implemented by the logic element is decomposed about logical variables to identify factors corresponding to combinations of the logical variables and their complements. A pass transistor network is provided for implementing the pass network function in accordance with this decomposition. The pass transistor network includes ordered arrangements of pass transistors that correspond to the combinations of variables and complements resulting from the logical decomposition. The logic elements may act as selection circuits and be integrated with memory and buffer elements.

Ultrashort Channel Length Black Phosphorus Field-Effect Transistors.

PubMed

Miao, Jinshui; Zhang, Suoming; Cai, Le; Scherr, Martin; Wang, Chuan

2015-09-22

This paper reports high-performance top-gated black phosphorus (BP) field-effect transistors with channel lengths down to 20 nm fabricated using a facile angle evaporation process. By controlling the evaporation angle, the channel length of the transistors can be reproducibly controlled to be anywhere between 20 and 70 nm. The as-fabricated 20 nm top-gated BP transistors exhibit respectable on-state current (174 μA/μm) and transconductance (70 μS/μm) at a VDS of 0.1 V. Due to the use of two-dimensional BP as the channel material, the transistors exhibit relatively small short channel effects, preserving a decent on-off current ratio of 10(2) even at an extremely small channel length of 20 nm. Additionally, unlike the unencapsulated BP devices, which are known to be chemically unstable in ambient conditions, the top-gated BP transistors passivated by the Al2O3 gate dielectric layer remain stable without noticeable degradation in device performance after being stored in ambient conditions for more than 1 week. This work demonstrates the great promise of atomically thin BP for applications in ultimately scaled transistors.

Low electron mobility of field-effect transistor determined by modulated magnetoresistance

NASA Astrophysics Data System (ADS)

Tauk, R.; Łusakowski, J.; Knap, W.; Tiberj, A.; Bougrioua, Z.; Azize, M.; Lorenzini, P.; Sakowicz, M.; Karpierz, K.; Fenouillet-Beranger, C.; Cassé, M.; Gallon, C.; Boeuf, F.; Skotnicki, T.

2007-11-01

Room temperature magnetotransport experiments were carried out on field-effect transistors in magnetic fields up to 10 T. It is shown that measurements of the transistor magnetoresistance and its first derivative with respect to the gate voltage allow the derivation of the electron mobility in the gated part of the transistor channel, while the access/contact resistances and the transistor gate length need not be known. We demonstrate the potential of this method using GaN and Si field-effect transistors and discuss its importance for mobility measurements in transistors with nanometer gate length.

Application of the Johnson criteria to graphene transistors

NASA Astrophysics Data System (ADS)

Kelly, M. J.

2013-12-01

For 60 years, the Johnson criteria have guided the development of materials and the materials choices for field-effect and bipolar transistor technology. Intrinsic graphene is a semi-metal, precluding transistor applications, but only under lateral bias is a gap opened and transistor action possible. This first application of the Johnson criteria to biased graphene suggests that this material will struggle to ever achieve competitive commercial applications.

The effect of particle size on the toxic action of silver nanoparticles

NASA Astrophysics Data System (ADS)

Sosenkova, L. S.; Egorova, E. M.

2011-04-01

Silver nanoparticles in AOT reverse micelles were obtained by means of the biochemical synthesis. Synthesis of nanoparticles was carried out with variation of the three parameters of reverse-micellar systems: concentration of silver ions, concentration of the stabilizer (AOT) and hydration extent w = [H2O]/[AOT]. The combinations of varied parameters have been found, allowing to prepare micellar solutions of spherical silver nanoparticles with average sizes 4.6 and 9.5 nm and narrow size distribution. From micellar solution the nanoparticles were transferred into the water phase; water solutions of the nanoparticles were used for testing their biological activity. Our assay is based on negative chemotaxis, a motile reaction of cells to an unfavorable chemical environment. Plasmodium of the slime mold Physarum polycephalum used as an object is a multinuclear amoeboid cell with unlimited growth and the auto-oscillatory mode of locomotion. In researches of chemotaxis on plasmodium it is learned that silver nanoparticles of smaller size exhibit a higher biological activity (behave as stronger repellent) and this correlates with the literary data obtained in studies of silver nanoparticles interaction with other biological objects.

Outlook and emerging semiconducting materials for ambipolar transistors.

PubMed

Bisri, Satria Zulkarnaen; Piliego, Claudia; Gao, Jia; Loi, Maria Antonietta

2014-02-26

Ambipolar or bipolar transistors are transistors in which both holes and electrons are mobile inside the conducting channel. This device allows switching among several states: the hole-dominated on-state, the off-state, and the electron-dominated on-state. In the past year, it has attracted great interest in exotic semiconductors, such as organic semiconductors, nanostructured materials, and carbon nanotubes. The ability to utilize both holes and electrons inside one device opens new possibilities for the development of more compact complementary metal-oxide semiconductor (CMOS) circuits, and new kinds of optoelectronic device, namely, ambipolar light-emitting transistors. This progress report highlights the recent progresses in the field of ambipolar transistors, both from the fundamental physics and application viewpoints. Attention is devoted to the challenges that should be faced for the realization of ambipolar transistors with different material systems, beginning with the understanding of the importance of interface modification, which heavily affects injections and trapping of both holes and electrons. The recent development of advanced gating applications, including ionic liquid gating, that open up more possibility to realize ambipolar transport in materials in which one type of charge carrier is highly dominant is highlighted. Between the possible applications of ambipolar field-effect transistors, we focus on ambipolar light-emitting transistors. We put this new device in the framework of its prospective for general lightings, embedded displays, current-driven laser, as well as for photonics-electronics interconnection. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Inverter circuits on freestanding flexible substrate using ZnO nanoparticles for cost-efficient electronics

NASA Astrophysics Data System (ADS)

Vidor, Fábio F.; Meyers, Thorsten; Müller, Kathrin; Wirth, Gilson I.; Hilleringmann, Ulrich

2017-11-01

Driven by the Internet of Things (IoT), flexible and transparent smart systems have been intensively researched by the scientific community and by several companies. This technology is already available for consumers in a wide range of innovative products, e.g., flexible displays, radio-frequency identification tags and wearable electronic skins which, for instance, collect and analyze data for medical applications. For these systems, thin-film transistors (TFTs) are the key elements responsible for the driving currents. Solution-based materials such as nanoparticle dispersions avail the fabrication on large-area substrates with high throughput processes. In this study, we discuss the integration of ZnO nanoparticle thin-film transistors and inverter circuits on freestanding polymeric substrates enclosing the main issues concerning the transfer of the integration process from a rigid substrate to a flexible one. The TFTs depict VON between -0.2 and 1 V, ION/IOFF > 104 and field-effect mobility >0.5 cm2 V-1 s-1. Additionally, in order to enhance the transistors and inverters performance, an adaptation on the device configuration, from an inverted coplanar to an inverted staggered setup, was conducted and analyzed. By employing the inverted staggered setup a considerable increase in the contact quality between the semiconductor and the drain and source electrodes was observed. As the integrated devices depict electrical characteristics which enable the fabrication of electronic circuits for the low-cost sector, inverters were fabricated and characterized, evaluating the circuit's gain as function of the applied supply voltage and circuit's geometric ratio.

Microwave assisted synthesis and characterisation of a zinc oxide/tobacco mosaic virus hybrid material. An active hybrid semiconductor in a field-effect transistor device.

PubMed

Sanctis, Shawn; Hoffmann, Rudolf C; Eiben, Sabine; Schneider, Jörg J

2015-01-01

Tobacco mosaic virus (TMV) has been employed as a robust functional template for the fabrication of a TMV/zinc oxide field effect transistor (FET). A microwave based approach, under mild conditions was employed to synthesize stable zinc oxide (ZnO) nanoparticles, employing a molecular precursor. Insightful studies of the decomposition of the precursor were done using NMR spectroscopy and material characterization of the hybrid material derived from the decomposition was achieved using dynamic light scattering (DLS), transmission electron microscopy (TEM), grazing incidence X-ray diffractometry (GI-XRD) and atomic force microscopy (AFM). TEM and DLS data confirm the formation of crystalline ZnO nanoparticles tethered on top of the virus template. GI-XRD investigations exhibit an orientated nature of the deposited ZnO film along the c-axis. FET devices fabricated using the zinc oxide mineralized virus template material demonstrates an operational transistor performance which was achieved without any high-temperature post-processing steps. Moreover, a further improvement in FET performance was observed by adjusting an optimal layer thickness of the deposited ZnO on top of the TMV. Such a bio-inorganic nanocomposite semiconductor material accessible using a mild and straightforward microwave processing technique could open up new future avenues within the field of bio-electronics.

Synthesis of bi-phase dispersible core-shell FeAu@ZnO magneto-opto-fluorescent nanoparticles

NASA Astrophysics Data System (ADS)

Li, Xue-Mei; Liu, Hong-Ling; Liu, Xiao; Fang, Ning; Wang, Xian-Hong; Wu, Jun-Hua

2015-11-01

Bi-phase dispersible core-shell FeAu@ZnO magneto-opto-fluorescent nanoparticles were synthesized by a modified nanoemulsion process using poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEO-PPO-PEO) as the surfactant. The morphology and crystal structure of the nanoparticles were studied by TEM/HRTEM and XRD. The nanoparticles manifest soft ferromagnetic and/or near superparamagnetic behavior with a small coercivity of ~19 Oe at room temperature. The corresponding magnetic hysteresis curves were elucidated by the modified Langevin equation. The FTIR study confirms the PEO-PPO-PEO molecules on the surface of the nanoparticles. The UV-vis and PL results reveal the well-behaved absorption bands including surface plasmon resonance and multiple visible fingerprint photoluminescent emissions of the nanoparticles dispersed in both hydrophilic and hydrophobic solvents. Moreover, the processes of solvent dispersion-collection of the nanoparticles were demonstrated for application readiness of such core-shell nanostructures.

Synthesis of bi-phase dispersible core-shell FeAu@ZnO magneto-opto-fluorescent nanoparticles

PubMed Central

Li, Xue-Mei; Liu, Hong-Ling; Liu, Xiao; Fang, Ning; Wang, Xian-Hong; Wu, Jun-Hua

2015-01-01

Bi-phase dispersible core-shell FeAu@ZnO magneto-opto-fluorescent nanoparticles were synthesized by a modified nanoemulsion process using poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEO-PPO-PEO) as the surfactant. The morphology and crystal structure of the nanoparticles were studied by TEM/HRTEM and XRD. The nanoparticles manifest soft ferromagnetic and/or near superparamagnetic behavior with a small coercivity of ~19 Oe at room temperature. The corresponding magnetic hysteresis curves were elucidated by the modified Langevin equation. The FTIR study confirms the PEO-PPO-PEO molecules on the surface of the nanoparticles. The UV-vis and PL results reveal the well-behaved absorption bands including surface plasmon resonance and multiple visible fingerprint photoluminescent emissions of the nanoparticles dispersed in both hydrophilic and hydrophobic solvents. Moreover, the processes of solvent dispersion-collection of the nanoparticles were demonstrated for application readiness of such core-shell nanostructures. PMID:26548369

Flexible Proton-Gated Oxide Synaptic Transistors on Si Membrane.

PubMed

Zhu, Li Qiang; Wan, Chang Jin; Gao, Ping Qi; Liu, Yang Hui; Xiao, Hui; Ye, Ji Chun; Wan, Qing

2016-08-24

Ion-conducting materials have received considerable attention for their applications in fuel cells, electrochemical devices, and sensors. Here, flexible indium zinc oxide (InZnO) synaptic transistors with multiple presynaptic inputs gated by proton-conducting phosphorosilicate glass-based electrolyte films are fabricated on ultrathin Si membranes. Transient characteristics of the proton gated InZnO synaptic transistors are investigated, indicating stable proton-gating behaviors. Short-term synaptic plasticities are mimicked on the proposed proton-gated synaptic transistors. Furthermore, synaptic integration regulations are mimicked on the proposed synaptic transistor networks. Spiking logic modulations are realized based on the transition between superlinear and sublinear synaptic integration. The multigates coupled flexible proton-gated oxide synaptic transistors may be interesting for neuroinspired platforms with sophisticated spatiotemporal information processing.

Proton Damage Effects on Carbon Nanotube Field-Effect Transistors

DTIC Science & Technology

2014-06-19

PROTON DAMAGE EFFECTS ON CARBON NANOTUBE FIELD-EFFECT TRANSISTORS THESIS Evan R. Kemp, Ctr...United States. AFIT-ENP-T-14-J-39 PROTON DAMAGE EFFECTS ON CARBON NANOTUBE FIELD-EFFECT TRANSISTORS THESIS Presented to...PROTON DAMAGE EFFECTS ON CARBON NANOTUBE FIELD-EFFECT TRANSISTORS Evan R. Kemp, BS Ctr, USAF Approved: // Signed

Alkylamine capped metal nanoparticle "inks" for printable SERS substrates, electronics and broadband photodetectors.

PubMed

Polavarapu, Lakshminarayana; Manga, Kiran Kumar; Yu, Kuai; Ang, Priscilla Kailian; Cao, Hanh Duyen; Balapanuru, Janardhan; Loh, Kian Ping; Xu, Qing-Hua

2011-05-01

We report a facile and general method for the preparation of alkylamine capped metal (Au and Ag) nanoparticle "ink" with high solubility. Using these metal nanoparticle "inks", we have demonstrated their applications for large scale fabrication of highly efficient surface enhanced Raman scattering (SERS) substrates by a facile solution processing method. These SERS substrates can detect analytes down to a few nM. The flexible plastic SERS substrates have also been demonstrated. The annealing temperature dependent conductivity of the nanoparticle films indicated a transition temperature above which high conductivity was achieved. The transition temperature could be tailored to the plastic compatible temperatures by using proper alkylamine as the capping agent. The ultrafast electron relaxation studies of the nanoparticle films demonstrated that faster electron relaxation was observed at higher annealing temperatures due to stronger electronic coupling between the nanoparticles. The applications of these highly concentrated alkylamine capped metal nanoparticle inks for the printable electronics were demonstrated by printing the oleylamine capped gold nanoparticles ink as source and drain for the graphene field effect transistor. Furthermore, the broadband photoresponse properties of the Au and Ag nanoparticle films have been demonstrated by using visible and near-infrared lasers. These investigations demonstrate that these nanoparticle "inks" are promising for applications in printable SERS substrates, electronics, and broadband photoresponse devices. © The Royal Society of Chemistry 2011

A nanoscale piezoelectric transformer for low-voltage transistors.

PubMed

Agarwal, Sapan; Yablonovitch, Eli

2014-11-12

A novel piezoelectric voltage transformer for low-voltage transistors is proposed. Placing a piezoelectric transformer on the gate of a field-effect transistor results in the piezoelectric transformer field-effect transistor that can switch at significantly lower voltages than a conventional transistor. The piezoelectric transformer operates by using one piezoelectric to squeeze another piezoelectric to generate a higher output voltage than the input voltage. Multiple piezoelectrics can be used to squeeze a single piezoelectric layer to generate an even higher voltage amplification. Coupled electrical and mechanical modeling in COMSOL predicts a 12.5× voltage amplification for a six-layer piezoelectric transformer. This would lead to more than a 150× reduction in the power needed for communications.

Thermoseeds for interstitial magnetic hyperthermia: from bioceramics to nanoparticles

NASA Astrophysics Data System (ADS)

Baeza, A.; Arcos, D.; Vallet-Regí, M.

2013-12-01

The development of magnetic materials for interstitial hyperthermia treatment of cancer is an ever evolving research field which provides new alternatives to antitumoral therapies. The development of biocompatible magnetic materials has resulted in new biomaterials with multifunctional properties, which are able to adapt to the complex scenario of tumoral processes. Once implanted or injected in the body, magnetic materials can behave as thermoseeds under the effect of AC magnetic fields. Magnetic bioceramics aimed to treat bone tumors and magnetic nanoparticles are among the most studied thermoseeds, and supply different solutions for the different scenarios in cancerous processes. This paper reviews some of the biomaterials used for bone cancer treatment and skeletal reinforcing, as well as the more complex topic of magnetic nanoparticles for intracellular targeting and hyperthermia.

Thermoseeds for interstitial magnetic hyperthermia: from bioceramics to nanoparticles.

PubMed

Baeza, A; Arcos, D; Vallet-Regí, M

2013-12-04

The development of magnetic materials for interstitial hyperthermia treatment of cancer is an ever evolving research field which provides new alternatives to antitumoral therapies. The development of biocompatible magnetic materials has resulted in new biomaterials with multifunctional properties, which are able to adapt to the complex scenario of tumoral processes. Once implanted or injected in the body, magnetic materials can behave as thermoseeds under the effect of AC magnetic fields. Magnetic bioceramics aimed to treat bone tumors and magnetic nanoparticles are among the most studied thermoseeds, and supply different solutions for the different scenarios in cancerous processes. This paper reviews some of the biomaterials used for bone cancer treatment and skeletal reinforcing, as well as the more complex topic of magnetic nanoparticles for intracellular targeting and hyperthermia.

Electrochemical doping for lowering contact barriers in organic field effect transistors

PubMed Central

Schaur, Stefan; Stadler, Philipp; Meana-Esteban, Beatriz; Neugebauer, Helmut; Serdar Sariciftci, N.

2012-01-01

By electrochemically p-doping pentacene in the vicinity of the source-drain electrodes in organic field effect transistors the injection barrier for holes is decreased. The focus of this work is put on the influence of the p-doping process on the transistor performance. Cyclic voltammetry performed on a pentacene based transistor exhibits a reversible p-doping response. This doped state is evoked at the transistor injection electrodes. An improvement is observed when comparing transistor characteristics before and after the doping process apparent by an improved transistor on-current. This effect is reflected in the analysis of the contact resistances of the devices. PMID:23483101

Magnetic Vortex Based Transistor Operations

PubMed Central

Kumar, D.; Barman, S.; Barman, A.

2014-01-01

Transistors constitute the backbone of modern day electronics. Since their advent, researchers have been seeking ways to make smaller and more efficient transistors. Here, we demonstrate a sustained amplification of magnetic vortex core gyration in coupled two and three vortices by controlling their relative core polarities. This amplification is mediated by a cascade of antivortex solitons travelling through the dynamic stray field. We further demonstrated that the amplification can be controlled by switching the polarity of the middle vortex in a three vortex sequence and the gain can be controlled by the input signal amplitude. An attempt to show fan–out operation yielded gain for one of the symmetrically placed branches which can be reversed by switching the core polarity of all the vortices in the network. The above observations promote the magnetic vortices as suitable candidates to work as stable bipolar junction transistors (BJT). PMID:24531235

Magnetic vortex based transistor operations.

PubMed

Kumar, D; Barman, S; Barman, A

2014-02-17

Transistors constitute the backbone of modern day electronics. Since their advent, researchers have been seeking ways to make smaller and more efficient transistors. Here, we demonstrate a sustained amplification of magnetic vortex core gyration in coupled two and three vortices by controlling their relative core polarities. This amplification is mediated by a cascade of antivortex solitons travelling through the dynamic stray field. We further demonstrated that the amplification can be controlled by switching the polarity of the middle vortex in a three vortex sequence and the gain can be controlled by the input signal amplitude. An attempt to show fan-out operation yielded gain for one of the symmetrically placed branches which can be reversed by switching the core polarity of all the vortices in the network. The above observations promote the magnetic vortices as suitable candidates to work as stable bipolar junction transistors (BJT).

Magnetic Vortex Based Transistor Operations

NASA Astrophysics Data System (ADS)

Kumar, D.; Barman, S.; Barman, A.

2014-02-01

Transistors constitute the backbone of modern day electronics. Since their advent, researchers have been seeking ways to make smaller and more efficient transistors. Here, we demonstrate a sustained amplification of magnetic vortex core gyration in coupled two and three vortices by controlling their relative core polarities. This amplification is mediated by a cascade of antivortex solitons travelling through the dynamic stray field. We further demonstrated that the amplification can be controlled by switching the polarity of the middle vortex in a three vortex sequence and the gain can be controlled by the input signal amplitude. An attempt to show fan-out operation yielded gain for one of the symmetrically placed branches which can be reversed by switching the core polarity of all the vortices in the network. The above observations promote the magnetic vortices as suitable candidates to work as stable bipolar junction transistors (BJT).

High current gain transistor laser

PubMed Central

Liang, Song; Qiao, Lijun; Zhu, Hongliang; Wang, Wei

2016-01-01

A transistor laser (TL), having the structure of a transistor with multi-quantum wells near its base region, bridges the functionality gap between lasers and transistors. However, light emission is produced at the expense of current gain for all the TLs reported up to now, leading to a very low current gain. We propose a novel design of TLs, which have an n-doped InP layer inserted in the emitter ridge. Numerical studies show that a current flow aperture for only holes can be formed in the center of the emitter ridge. As a result, the common emitter current gain can be as large as 143.3, which is over 15 times larger than that of a TL without the aperture. Besides, the effects of nonradiative recombination defects can be reduced greatly because the flow of holes is confined in the center region of the emitter ridge. PMID:27282466

Liquid crystals for organic transistors (Conference Presentation)

NASA Astrophysics Data System (ADS)

Hanna, Jun-ichi; Iino, Hiroaki

2016-09-01

Liquid crystals are a new type of organic semiconductors exhibiting molecular orientation in self-organizing manner, and have high potential for device applications. In fact, various device applications have been proposed so far, including photosensors, solar cells, light emitting diodes, field effect transistors, and so on.. However, device performance in those fabricated with liquid crystals is less than those of devices fabricated with conventional materials in spite of unique features of liquid crystals. Here we discuss how we can utilize the liquid crystallinity in organic transistors and how we can overcome conventional non-liquid crystalline organic transistor materials. Then, we demonstrate high performance organic transistors fabricated with a smectic E liquid crystal of Ph-BTBT-10, which show high mobility of over 10cm2/Vs and high thermal durability of over 200oC in OFETs fabricated with its spin-coated polycrystalline thin films.

Transistor circuit increases range of logarithmic current amplifier

NASA Technical Reports Server (NTRS)

Gilmour, G.

1966-01-01

Circuit increases the range of a logarithmic current amplifier by combining a commercially available amplifier with a silicon epitaxial transistor. A temperature compensating network is provided for the transistor.

Hybrid nanocatalysts containing enzymes and metallic nanoparticles for ethanol/O2 biofuel cell

NASA Astrophysics Data System (ADS)

Aquino Neto, S.; Almeida, T. S.; Palma, L. M.; Minteer, S. D.; de Andrade, A. R.

2014-08-01

We report the preparation of hybrid nanostructured bioanodes containing the enzyme alcohol dehydrogenase (ADH) with either Au, Pt, or Pt0.75Sn0.25 nanoparticles for use in ethanol/O2 hybrid biofuel cells. We describe two different methodologies for the preparation of the bioanodes: in a first case, multi walled carbon nanotubes (MWCNTs) were employed as a support for the metallic nanoparticles and TBAB-modified Nafion® aided enzyme immobilization. In the second case, we immobilized the enzymes using dendrimers-encapsulated nanoparticles as the agent for enzyme anchoring. The biofuel cell tests showed that the addition of metallic nanoparticles to the bioanode structure enhanced the overall biofuel cell performance. The bioelectrode containing Au nanoparticles displaying the best performance, with an open circuit potential of 0.61 ± 0.05 V and a maximum power density of 155 ± 11 μW cm-2. NADH cyclic voltammetric experiments indicated that Au nanoparticles behaved as a catalyst toward NADH oxidation. Comparing the two protocols we used to synthetized nanoparticles, the sample containing the Au nanoparticles supported on MWCNTs furnished fourfold higher values. Therefore, from the satisfactory results obtained, it can be inferred that the combination of small amounts of metallic nanoparticles with enzymes improve bioanode performance.

Organic/Inorganic Nano-hybrids with High Dielectric Constant for Organic Thin Film Transistor Applications

NASA Astrophysics Data System (ADS)

Yu, Yang-Yen; Jiang, Ai-Hua; Lee, Wen-Ya

2016-11-01

The organic material soluble polyimide (PI) and organic-inorganic hybrid PI-barium titanate (BaTiO3) nanoparticle dielectric materials (IBX, where X is the concentration of BaTiO3 nanoparticles in a PI matrix) were successfully synthesized through a sol-gel process. The effects of various BaTiO3 contents on the hybrid film performance and performance optimization were investigated. Furthermore, pentacene-based organic thin film transistors (OTFTs) with PI-BaTiO3/polymethylmethacrylate or cyclic olefin copolymer (COC)-modified gate dielectrics were fabricated and examined. The hybrid materials showed effective dispersion of BaTiO3 nanoparticles in the PI matrix and favorable thermal properties. X-ray diffraction patterns revealed that the BaTiO3 nanoparticles had a perovskite structure. The hybrid films exhibited high formability and planarity. The IBX hybrid dielectric films exhibited tunable insulating properties such as the dielectric constant value and capacitance in ranges of 4.0-8.6 and 9.2-17.5 nF cm-2, respectively. Adding the modified layer caused the decrease of dielectric constant values and capacitances. The modified dielectric layer without cross-linking displayed a hydrophobic surface. The electrical characteristics of the pentacene-based OTFTs were enhanced after the surface modification. The optimal condition for the dielectric layer was 10 wt% hybrid film with the COC-modified layer; moreover, the device exhibited a threshold voltage of 0.12 V, field-effect mobility of 4.32 × 10-1 cm2 V-1 s-1, and on/off current of 8.4 × 107.

Stretchable transistors with buckled carbon nanotube films as conducting channels

DOEpatents

Arnold, Michael S; Xu, Feng

2015-03-24

Thin-film transistors comprising buckled films comprising carbon nanotubes as the conductive channel are provided. Also provided are methods of fabricating the transistors. The transistors, which are highly stretchable and bendable, exhibit stable performance even when operated under high tensile strains.

Npn double heterostructure bipolar transistor with ingaasn base region

DOEpatents

Chang, Ping-Chih; Baca, Albert G.; Li, Nein-Yi; Hou, Hong Q.; Ashby, Carol I. H.

2004-07-20

An NPN double heterostructure bipolar transistor (DHBT) is disclosed with a base region comprising a layer of p-type-doped indium gallium arsenide nitride (InGaAsN) sandwiched between n-type-doped collector and emitter regions. The use of InGaAsN for the base region lowers the transistor turn-on voltage, V.sub.on, thereby reducing power dissipation within the device. The NPN transistor, which has applications for forming low-power electronic circuitry, is formed on a gallium arsenide (GaAs) substrate and can be fabricated at commercial GaAs foundries. Methods for fabricating the NPN transistor are also disclosed.

Organic field effect transistor with ultra high amplification

NASA Astrophysics Data System (ADS)

Torricelli, Fabrizio

2016-09-01

High-gain transistors are essential for the large-scale circuit integration, high-sensitivity sensors and signal amplification in sensing systems. Unfortunately, organic field-effect transistors show limited gain, usually of the order of tens, because of the large contact resistance and channel-length modulation. Here we show organic transistors fabricated on plastic foils enabling unipolar amplifiers with ultra-gain. The proposed approach is general and opens up new opportunities for ultra-large signal amplification in organic circuits and sensors.

Behaving as or behaving as if? Children's conceptions of personified robots and the emergence of a new ontological category.

PubMed

Severson, Rachel L; Carlson, Stephanie M

2010-01-01

Imagining another's perspective is an achievement in social cognition and underlies empathic concern and moral regard. Imagination is also within the realm of fantasy, and may take the form of imaginary play in children and imaginative production in adults. Yet, an interesting and provocative question emerges in the case of personified robots: How do people conceive of life-like robots? Do people imagine about robots' experiences? If so, do these imaginings reflect their actual or pretend beliefs about robots? The answers to these questions bear on the possibility that personified robots represent the emergence of a new ontological category. We draw on simulation theory as a framework for imagining others' internal states as well as a means for imaginative play. We then turn to the literature on people's and, in particular, children's conceptions of personified technologies and raise the question of the veracity of children's beliefs about personified robots (i.e., are they behaving as or behaving as if?). Finally, we consider the suggestion that such personified technologies represent the emergence of a new ontological category and offer some suggestions for future research in this important emerging area of social cognition. Copyright © 2010. Published by Elsevier Ltd.

Influence of natural organic matter (NOM) coatings on nanoparticle adsorption onto supported lipid bilayers.

PubMed

Bo, Zhang; Avsar, Saziye Yorulmaz; Corliss, Michael K; Chung, Minsub; Cho, Nam-Joon

2017-10-05

As the worldwide usage of nanoparticles in commercial products continues to increase, there is growing concern about the environmental risks that nanoparticles pose to biological systems, including potential damage to cellular membranes. A detailed understanding of how different types of nanoparticles behave in environmentally relevant conditions is imperative for predicting and mitigating potential membrane-associated toxicities. Herein, we investigated the adsorption of two popular nanoparticles (silver and buckminsterfullerene) onto biomimetic supported lipid bilayers of varying membrane charge (positive and negative). The quartz crystal microbalance-dissipation (QCM-D) measurement technique was employed to track the adsorption kinetics. Particular attention was focused on understanding how natural organic matter (NOM) coatings affect nanoparticle-bilayer interactions. Both types of nanoparticles preferentially adsorbed onto the positively charged bilayers, although NOM coatings on the nanoparticle and lipid bilayer surfaces could either inhibit or promote adsorption in certain electrolyte conditions. While past findings showed that NOM coatings inhibit membrane adhesion, our findings demonstrate that the effects of NOM coatings are more nuanced depending on the type of nanoparticle and electrolyte condition. Taken together, the results demonstrate that NOM coatings can modulate the lipid membrane interactions of various nanoparticles, suggesting a possible way to improve the environmental safety of nanoparticles. Copyright © 2017 Elsevier B.V. All rights reserved.

Carrier mobility in organic field-effect transistors

NASA Astrophysics Data System (ADS)

Xu, Yong; Benwadih, Mohamed; Gwoziecki, Romain; Coppard, Romain; Minari, Takeo; Liu, Chuan; Tsukagoshi, Kazuhito; Chroboczek, Jan; Balestra, Francis; Ghibaudo, Gerard

2011-11-01

A study of carrier transport in top-gate and bottom-contact TIPS-pentacene organic field-effect transistors (OFETs) based on mobility is presented. Among three mobilities extracted by different methods, the low-field mobility obtained by the Y function exhibits the best reliability and ease for use, whereas the widely applied field-effect mobility is not reliable, particularly in short-channel transistors and at low temperatures. A detailed study of contact transport reveals its strong impact on short-channel transistors, suggesting that a more intrinsic transport analysis is better implemented in relatively longer-channel devices. The observed temperature dependences of mobility are well explained by a transport model with Gaussian-like diffusivity band tails, different from diffusion in localized states band tails. This model explicitly interprets the non-zero constant mobility at low temperatures and clearly demonstrates the effects of disorder and hopping transport on temperature and carrier density dependences of mobility in organic transistors.

Theory of Magnetic Bipolar Transistors

NASA Astrophysics Data System (ADS)

Zutic, Igor; Fabian, Jaroslav; Das Sarma, S.

2003-03-01

We introduce the concept of a magnetic bipolar transistor (MBT) (J. Fabian, I. Zutic, S. Das Sarma, cond-mat/0211639.), which can be realized using already available materials. The transistor has at least one magnetic region (emitter, base, or collector) characterized by spin-splitting of the carrier bands. In addition, nonequilibrium (source) spin in MBTs can be induced by external means (electrically or optically). The theory of ideal MBTs is developed and discussed in the forward active regime where the transistors can amplify signals. It is shown that source spin can be injected from the emitter to the collector. It is predicted that electrical current gain (amplification) can be controlled effectively by magnetic field and source spin. If a base is a ferromagnetic semiconductor we suggest several methods for using spin-polarized bipolar transport (I. Zutic, J. Fabian, S. Das Sarma, Phys. Rev. Lett. f 88, 066603 (2002); J. Fabian, I. Zutic, S. Das Sarma, Phys. Rev. B f 66, 165301 (2002).) to manipulate semiconductor ferromagnetism.

Validation of BEHAVE fire behavior predictions in oak savannas using five fuel models

Treesearch

Keith Grabner; John Dwyer; Bruce Cutter

1997-01-01

Prescribed fire is a valuable tool in the restoration and management of oak savannas. BEHAVE, a fire behavior prediction system developed by the United States Forest Service, can be a useful tool when managing oak savannas with prescribed fire. BEHAVE predictions of fire rate-of-spread and flame length were validated using four standardized fuel models: Fuel Model 1 (...

A steep-slope transistor based on abrupt electronic phase transition

NASA Astrophysics Data System (ADS)

Shukla, Nikhil; Thathachary, Arun V.; Agrawal, Ashish; Paik, Hanjong; Aziz, Ahmedullah; Schlom, Darrell G.; Gupta, Sumeet Kumar; Engel-Herbert, Roman; Datta, Suman

2015-08-01

Collective interactions in functional materials can enable novel macroscopic properties like insulator-to-metal transitions. While implementing such materials into field-effect-transistor technology can potentially augment current state-of-the-art devices by providing unique routes to overcome their conventional limits, attempts to harness the insulator-to-metal transition for high-performance transistors have experienced little success. Here, we demonstrate a pathway for harnessing the abrupt resistivity transformation across the insulator-to-metal transition in vanadium dioxide (VO2), to design a hybrid-phase-transition field-effect transistor that exhibits gate controlled steep (`sub-kT/q') and reversible switching at room temperature. The transistor design, wherein VO2 is implemented in series with the field-effect transistor's source rather than into the channel, exploits negative differential resistance induced across the VO2 to create an internal amplifier that facilitates enhanced performance over a conventional field-effect transistor. Our approach enables low-voltage complementary n-type and p-type transistor operation as demonstrated here, and is applicable to other insulator-to-metal transition materials, offering tantalizing possibilities for energy-efficient logic and memory applications.

A steep-slope transistor based on abrupt electronic phase transition.

PubMed

Shukla, Nikhil; Thathachary, Arun V; Agrawal, Ashish; Paik, Hanjong; Aziz, Ahmedullah; Schlom, Darrell G; Gupta, Sumeet Kumar; Engel-Herbert, Roman; Datta, Suman

2015-08-07

Collective interactions in functional materials can enable novel macroscopic properties like insulator-to-metal transitions. While implementing such materials into field-effect-transistor technology can potentially augment current state-of-the-art devices by providing unique routes to overcome their conventional limits, attempts to harness the insulator-to-metal transition for high-performance transistors have experienced little success. Here, we demonstrate a pathway for harnessing the abrupt resistivity transformation across the insulator-to-metal transition in vanadium dioxide (VO2), to design a hybrid-phase-transition field-effect transistor that exhibits gate controlled steep ('sub-kT/q') and reversible switching at room temperature. The transistor design, wherein VO2 is implemented in series with the field-effect transistor's source rather than into the channel, exploits negative differential resistance induced across the VO2 to create an internal amplifier that facilitates enhanced performance over a conventional field-effect transistor. Our approach enables low-voltage complementary n-type and p-type transistor operation as demonstrated here, and is applicable to other insulator-to-metal transition materials, offering tantalizing possibilities for energy-efficient logic and memory applications.

Enhanced transconductance in a double-gate graphene field-effect transistor

NASA Astrophysics Data System (ADS)

Hwang, Byeong-Woon; Yeom, Hye-In; Kim, Daewon; Kim, Choong-Ki; Lee, Dongil; Choi, Yang-Kyu

2018-03-01

Multi-gate transistors, such as double-gate, tri-gate and gate-all-around transistors are the most advanced Si transistor structure today. Here, a genuine double-gate transistor with a graphene channel is experimentally demonstrated. The top and bottom gates of the double-gate graphene field-effect transistor (DG GFET) are electrically connected so that the conductivity of the graphene channel can be modulated simultaneously by both the top and bottom gate. A single-gate graphene field-effect transistor (SG GFET) with only the top gate is also fabricated as a control device. For systematical analysis, the transfer characteristics of both GFETs were measured and compared. Whereas the maximum transconductance of the SG GFET was 17.1 μS/μm, that of the DG GFET was 25.7 μS/μm, which is approximately a 50% enhancement. The enhancement of the transconductance was reproduced and comprehensively explained by a physics-based compact model for GFETs. The investigation of the enhanced transfer characteristics of the DG GFET in this work shows the possibility of a multi-gate architecture for high-performance graphene transistor technology.

Modeling of charge transport in ion bipolar junction transistors.

PubMed

Volkov, Anton V; Tybrandt, Klas; Berggren, Magnus; Zozoulenko, Igor V

2014-06-17

Spatiotemporal control of the complex chemical microenvironment is of great importance to many fields within life science. One way to facilitate such control is to construct delivery circuits, comprising arrays of dispensing outlets, for ions and charged biomolecules based on ionic transistors. This allows for addressability of ionic signals, which opens up for spatiotemporally controlled delivery in a highly complex manner. One class of ionic transistors, the ion bipolar junction transistors (IBJTs), is especially attractive for these applications because these transistors are functional at physiological conditions and have been employed to modulate the delivery of neurotransmitters to regulate signaling in neuronal cells. Further, the first integrated complementary ionic circuits were recently developed on the basis of these ionic transistors. However, a detailed understanding of the device physics of these transistors is still lacking and hampers further development of components and circuits. Here, we report on the modeling of IBJTs using Poisson's and Nernst-Planck equations and the finite element method. A two-dimensional model of the device is employed that successfully reproduces the main characteristics of the measurement data. On the basis of the detailed concentration and potential profiles provided by the model, the different modes of operation of the transistor are analyzed as well as the transitions between the different modes. The model correctly predicts the measured threshold voltage, which is explained in terms of membrane potentials. All in all, the results provide the basis for a detailed understanding of IBJT operation. This new knowledge is employed to discuss potential improvements of ion bipolar junction transistors in terms of miniaturization and device parameters.

Development and fabrication of improved power transistor switches

NASA Technical Reports Server (NTRS)

Hower, P. L.; Chu, C. K.

1979-01-01

A new class of high-voltage power transistors was achieved by adapting present interdigitated thyristor processing techniques to the fabrication of npn Si transistors. Present devices are 2.3 cm in diameter and have V sub CEO (sus) in the range of 400 to 600V. V sub CEO (sus) = 450V devices were made with an (h sub FE)(I sub C) product of 900A at V sub CE = 2.5V. The electrical performance obtained was consistent with the predictions of an optimum design theory specifically developed for power switching transistors. The device design, wafer processing, and assembly techniques are described. Experimental measurements of the dc characteristics, forward SOA, and switching times are included. A new method of characterizing the switching performance of power transistors is proposed.

Large scale electromechanical transistor with application in mass sensing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin, Leisheng; Li, Lijie, E-mail: L.Li@swansea.ac.uk

Nanomechanical transistor (NMT) has evolved from the single electron transistor, a device that operates by shuttling electrons with a self-excited central conductor. The unfavoured aspects of the NMT are the complexity of the fabrication process and its signal processing unit, which could potentially be overcome by designing much larger devices. This paper reports a new design of large scale electromechanical transistor (LSEMT), still taking advantage of the principle of shuttling electrons. However, because of the large size, nonlinear electrostatic forces induced by the transistor itself are not sufficient to drive the mechanical member into vibration—an external force has to bemore » used. In this paper, a LSEMT device is modelled, and its new application in mass sensing is postulated using two coupled mechanical cantilevers, with one of them being embedded in the transistor. The sensor is capable of detecting added mass using the eigenstate shifts method by reading the change of electrical current from the transistor, which has much higher sensitivity than conventional eigenfrequency shift approach used in classical cantilever based mass sensors. Numerical simulations are conducted to investigate the performance of the mass sensor.« less

Ideal Channel Field Effect Transistors

DTIC Science & Technology

2010-03-01

well as on /?-GaAs/w-GaAs homojunctions grown by molecular beam epitaxy (MBE). The diode I-Vs at reverse bias are plotted below. The measured breakdown...transistors and composite channel InAlAs/InGaAs/lnP/InAlAs high electron mobility transistors ( HEMTs ), which have taken the full advantage of the matched...result in a large number of dislocations in GaAs films epitaxially grown on wurtzite GaN. In this work, we have successfully integrated GaAs with GaN

Organic transistors manufactured using inkjet technology with subfemtoliter accuracy

PubMed Central

Sekitani, Tsuyoshi; Noguchi, Yoshiaki; Zschieschang, Ute; Klauk, Hagen; Someya, Takao

2008-01-01

A major obstacle to the development of organic transistors for large-area sensor, display, and circuit applications is the fundamental compromise between manufacturing efficiency, transistor performance, and power consumption. In the past, improving the manufacturing efficiency through the use of printing techniques has inevitably resulted in significantly lower performance and increased power consumption, while attempts to improve performance or reduce power have led to higher process temperatures and increased manufacturing cost. Here, we lift this fundamental limitation by demonstrating subfemtoliter inkjet printing to define metal contacts with single-micrometer resolution on the surface of high-mobility organic semiconductors to create high-performance p-channel and n-channel transistors and low-power complementary circuits. The transistors employ an ultrathin low-temperature gate dielectric based on a self-assembled monolayer that allows transistors and circuits on rigid and flexible substrates to operate with very low voltages. PMID:18362348

Transistors using crystalline silicon devices on glass

DOEpatents

McCarthy, Anthony M.

1995-01-01

A method for fabricating transistors using single-crystal silicon devices on glass. This method overcomes the potential damage that may be caused to the device during high voltage bonding and employs a metal layer which may be incorporated as part of the transistor. This is accomplished such that when the bonding of the silicon wafer or substrate to the glass substrate is performed, the voltage and current pass through areas where transistors will not be fabricated. After removal of the silicon substrate, further metal may be deposited to form electrical contact or add functionality to the devices. By this method both single and gate-all-around devices may be formed.

Field-effect transistors (2nd revised and enlarged edition)

NASA Astrophysics Data System (ADS)

Bocharov, L. N.

The design, principle of operation, and principal technical characteristics of field-effect transistors produced in the USSR are described. Problems related to the use of field-effect transistors in various radioelectronic devices are examined, and tables of parameters and mean statistical characteristics are presented for the main types of field-effect transistors. Methods for calculating various circuit components are discussed and illustrated by numerical examples.

Three dimensional-stacked complementary thin-film transistors using n-type Al:ZnO and p-type NiO thin-film transistors.

PubMed

Lee, Ching-Ting; Chen, Chia-Chi; Lee, Hsin-Ying

2018-03-05

The three dimensional inverters were fabricated using novel complementary structure of stacked bottom n-type aluminum-doped zinc oxide (Al:ZnO) thin-film transistor and top p-type nickel oxide (NiO) thin-film transistor. When the inverter operated at the direct voltage (V DD ) of 10 V and the input voltage from 0 V to 10 V, the obtained high performances included the output swing of 9.9 V, the high noise margin of 2.7 V, and the low noise margin of 2.2 V. Furthermore, the high performances of unskenwed inverter were demonstrated by using the novel complementary structure of the stacked n-type Al:ZnO thin-film transistor and p-type nickel oxide (NiO) thin-film transistor.

A PWM transistor inverter for an ac electric vehicle drive

NASA Technical Reports Server (NTRS)

Slicker, J. M.

1981-01-01

A prototype system consisting of closely integrated motor, inverter, and transaxle has been built in order to demonstrate the feasibility of a three-phase ac transistorized inverter for electric vehicle applications. The microprocessor-controlled inverter employs monolithic power transistors to drive an oil-cooled, three-phase induction traction motor at a peak output power of 30 kW from a 144 V battery pack. Transistor safe switching requirements are discussed, and a circuit is presented for recovering trapped snubber inductor energy at transistor turn-off.

Switching Transistor

NASA Technical Reports Server (NTRS)

1981-01-01

Westinghouse Electric Corporation's D60T transistors are used primarily as switching devices for controlling high power in electrical circuits. It enables reduction in the number and size of circuit components and promotes more efficient use of energy. Wide range of application from a popcorn popper to a radio frequency generator for solar cell production.

Programmable, automated transistor test system

NASA Technical Reports Server (NTRS)

Truong, L. V.; Sundburg, G. R.

1986-01-01

A programmable, automated transistor test system was built to supply experimental data on new and advanced power semiconductors. The data will be used for analytical models and by engineers in designing space and aircraft electric power systems. A pulsed power technique was used at low duty cycles in a nondestructive test to examine the dynamic switching characteristic curves of power transistors in the 500 to 1000 V, 10 to 100 A range. Data collection, manipulation, storage, and output are operator interactive but are guided and controlled by the system software.

I-V Characteristics of a Ferroelectric Field Effect Transistor

NASA Technical Reports Server (NTRS)

MacLeod, Todd C.; Ho, Fat Duen

1999-01-01

There are many possible uses for ferroelectric field effect transistors.To understand their application, a fundamental knowledge of their basic characteristics must first be found. In this research, the current and voltage characteristics of a field effect transistor are described. The effective gate capacitance and charge are derived from experimental data on an actual FFET. The general equation for a MOSFET is used to derive the internal characteristics of the transistor: This equation is modified slightly to describe the FFET characteristics. Experimental data derived from a Radiant Technologies FFET is used to calculate the internal transistor characteristics using fundamental MOSFET equations. The drain current was measured under several different gate and drain voltages and with different initial polarizations on the ferroelectric material in the transistor. Two different polarization conditions were used. One with the gate ferroelectric material polarized with a +9.0 volt write pulse and one with a -9.0 volt pulse.

Theory and Device Modeling for Nano-Structured Transistor Channels

DTIC Science & Technology

2011-06-01

zinc oxide ( ZnO ) thin film transistors ( TFTs ) that contain nanocrystalline grains on the order of ~20nm. The authors of ref. 1 present results...problem in order to determine the threshold voltage. 15. SUBJECT TERMS nano-structured transistor , mesoscopic, zinc oxide , ZnO , field-effect...and R. Neidhard, “Microwave ZnO Thin - Film Transistors ”, IEEE Electron Dev. Lett. 29, 1024 (2008); doi: 10.1109/LED.2008.2001635.

AlGaSb Buffer Layers for Sb-Based Transistors

DTIC Science & Technology

2010-01-01

transistor ( HEMT ), molecular beam epitaxy (MBE), field-effect transistor (FET), buffer layer INTRODUCTION High-electron-mobility transistors ( HEMTs ) with InAs...monolayers/s. The use of thinner buffer layers reduces molecular beam epitaxial growth time and source consumption. The buffer layers also exhibit...source. In addition, some of the flux from an Sb cell in a molecular beam epitaxy (MBE) system will deposit near the mouth of the cell, eventually

Sensing Reversible Protein–Ligand Interactions with Single-Walled Carbon Nanotube Field-Effect Transistors

PubMed Central

2015-01-01

We report on the reversible detection of CaptAvidin, a tyrosine modified avidin, with single-walled carbon nanotube (SWNT) field-effect transistors (FETs) noncovalently functionalized with biotin moieties using 1-pyrenebutyric acid as a linker. Binding affinities at different pH values were quantified, and the sensor’s response at various ionic strengths was analyzed. Furthermore, protein “fingerprints” of NeutrAvidin and streptavidin were obtained by monitoring their adsorption at several pH values. Moreover, gold nanoparticle decorated SWNT FETs were functionalized with biotin using 1-pyrenebutyric acid as a linker for the CNT surface and (±)-α-lipoic acid linkers for the gold surface, and reversible CaptAvidin binding is shown, paving the way for potential dual mode measurements with the addition of surface enhanced Raman spectroscopy (SERS). PMID:25126155

Mixed protonic and electronic conductors hybrid oxide synaptic transistors

NASA Astrophysics Data System (ADS)

Fu, Yang Ming; Zhu, Li Qiang; Wen, Juan; Xiao, Hui; Liu, Rui

2017-05-01

Mixed ionic and electronic conductor hybrid devices have attracted widespread attention in the field of brain-inspired neuromorphic systems. Here, mixed protonic and electronic conductor (MPEC) hybrid indium-tungsten-oxide (IWO) synaptic transistors gated by nanogranular phosphorosilicate glass (PSG) based electrolytes were obtained. Unique field-configurable proton self-modulation behaviors were observed on the MPEC hybrid transistor with extremely strong interfacial electric-double-layer effects. Temporally coupled synaptic plasticities were demonstrated on the MPEC hybrid IWO synaptic transistor, including depolarization/hyperpolarization, synaptic facilitation and depression, facilitation-stead/depression-stead behaviors, spiking rate dependent plasticity, and high-pass/low-pass synaptic filtering behaviors. MPEC hybrid synaptic transistors may find potential applications in neuron-inspired platforms.

Scalable fabrication of self-aligned graphene transistors and circuits on glass.

PubMed

Liao, Lei; Bai, Jingwei; Cheng, Rui; Zhou, Hailong; Liu, Lixin; Liu, Yuan; Huang, Yu; Duan, Xiangfeng

2012-06-13

Graphene transistors are of considerable interest for radio frequency (rf) applications. High-frequency graphene transistors with the intrinsic cutoff frequency up to 300 GHz have been demonstrated. However, the graphene transistors reported to date only exhibit a limited extrinsic cutoff frequency up to about 10 GHz, and functional graphene circuits demonstrated so far can merely operate in the tens of megahertz regime, far from the potential the graphene transistors could offer. Here we report a scalable approach to fabricate self-aligned graphene transistors with the extrinsic cutoff frequency exceeding 50 GHz and graphene circuits that can operate in the 1-10 GHz regime. The devices are fabricated on a glass substrate through a self-aligned process by using chemical vapor deposition (CVD) grown graphene and a dielectrophoretic assembled nanowire gate array. The self-aligned process allows the achievement of unprecedented performance in CVD graphene transistors with a highest transconductance of 0.36 mS/μm. The use of an insulating substrate minimizes the parasitic capacitance and has therefore enabled graphene transistors with a record-high extrinsic cutoff frequency (> 50 GHz) achieved to date. The excellent extrinsic cutoff frequency readily allows configuring the graphene transistors into frequency doubling or mixing circuits functioning in the 1-10 GHz regime, a significant advancement over previous reports (∼20 MHz). The studies open a pathway to scalable fabrication of high-speed graphene transistors and functional circuits and represent a significant step forward to graphene based radio frequency devices.

Transistors using crystalline silicon devices on glass

DOEpatents

McCarthy, A.M.

1995-05-09

A method is disclosed for fabricating transistors using single-crystal silicon devices on glass. This method overcomes the potential damage that may be caused to the device during high voltage bonding and employs a metal layer which may be incorporated as part of the transistor. This is accomplished such that when the bonding of the silicon wafer or substrate to the glass substrate is performed, the voltage and current pass through areas where transistors will not be fabricated. After removal of the silicon substrate, further metal may be deposited to form electrical contact or add functionality to the devices. By this method both single and gate-all-around devices may be formed. 13 figs.

Eco-Friendly and Biodegradable Biopolymer Chitosan/Y₂O₃ Composite Materials in Flexible Organic Thin-Film Transistors.

PubMed

Du, Bo-Wei; Hu, Shao-Ying; Singh, Ranjodh; Tsai, Tsung-Tso; Lin, Ching-Chang; Ko, Fu-Hsiang

2017-09-03

The waste from semiconductor manufacturing processes causes serious pollution to the environment. In this work, a non-toxic material was developed under room temperature conditions for the fabrication of green electronics. Flexible organic thin-film transistors (OTFTs) on plastic substrates are increasingly in demand due to their high visible transmission and small size for use as displays and wearable devices. This work investigates and analyzes the structured formation of aqueous solutions of the non-toxic and biodegradable biopolymer, chitosan, blended with high-k-value, non-toxic, and biocompatible Y₂O₃ nanoparticles. Chitosan thin films blended with Y₂O₃ nanoparticles were adopted as the gate dielectric thin film in OTFTs, and an improvement in the dielectric properties and pinholes was observed. Meanwhile, the on/off current ratio was increased by 100 times, and a low leakage current was observed. In general, the blended chitosan/Y₂O₃ thin films used as the gate dielectric of OTFTs are non-toxic, environmentally friendly, and operate at low voltages. These OTFTs can be used on surfaces with different curvature radii because of their flexibility.

Low-temperature solution-processed zinc oxide field effect transistor by blending zinc hydroxide and zinc oxide nanoparticle in aqueous solutions

NASA Astrophysics Data System (ADS)

Shin, Hyeonwoo; Kang, Chan-mo; Baek, Kyu-Ha; Kim, Jun Young; Do, Lee-Mi; Lee, Changhee

2018-05-01

We present a novel methods of fabricating low-temperature (180 °C), solution-processed zinc oxide (ZnO) transistors using a ZnO precursor that is blended with zinc hydroxide [Zn(OH)2] and zinc oxide hydrate (ZnO • H2O) in an ammonium solution. By using the proposed method, we successfully improved the electrical performance of the transistor in terms of the mobility (μ), on/off current ratio (I on/I off), sub-threshold swing (SS), and operational stability. Our new approach to forming a ZnO film was systematically compared with previously proposed methods. An atomic forced microscopic (AFM) image and an X-ray photoelectron spectroscopy (XPS) analysis showed that our method increases the ZnO crystallite size with less OH‑ impurities. Thus, we attribute the improved electrical performance to the better ZnO film formation using the blending methods.

Well behaved parametric class of relativistic charged fluid ball in general relativity

NASA Astrophysics Data System (ADS)

Pant, Neeraj

2011-04-01

The paper presents a class of interior solutions of Einstein-Maxwell field equations of general relativity for a static, spherically symmetric distribution of the charged fluid. This class of solutions describes well behaved charged fluid balls. The class of solutions gives us wide range of parameter K (0≤ K≤42) for which the solution is well behaved hence, suitable for modeling of super dense star. For this solution the mass of a star is maximized with all degree of suitability and by assuming the surface density ρ b =2×1014 g/cm3. Corresponding to K=2 and X=0.30, the maximum mass of the star comes out to be 4.96 M Θ with linear dimension 34.16 km and central redshift and surface redshift 2.1033 and 0.683 respectively. In absence of the charge we are left behind with the well behaved fourth model of Durgapal (J. Phys., A, Math. Gen. 15:2637, 1982).

Controlled n-Type Doping of Carbon Nanotube Transistors by an Organorhodium Dimer.

PubMed

Geier, Michael L; Moudgil, Karttikay; Barlow, Stephen; Marder, Seth R; Hersam, Mark C

2016-07-13

Single-walled carbon nanotube (SWCNT) transistors are among the most developed nanoelectronic devices for high-performance computing applications. While p-type SWCNT transistors are easily achieved through adventitious adsorption of atmospheric oxygen, n-type SWCNT transistors require extrinsic doping schemes. Existing n-type doping strategies for SWCNT transistors suffer from one or more issues including environmental instability, limited carrier concentration modulation, undesirable threshold voltage control, and/or poor morphology. In particular, commonly employed benzyl viologen n-type doping layers possess large thicknesses, which preclude top-gate transistor designs that underlie high-density integrated circuit layouts. To overcome these limitations, we report here the controlled n-type doping of SWCNT thin-film transistors with a solution-processed pentamethylrhodocene dimer. The charge transport properties of organorhodium-treated SWCNT thin films show consistent n-type behavior when characterized in both Hall effect and thin-film transistor geometries. Due to the molecular-scale thickness of the organorhodium adlayer, large-area arrays of top-gated, n-type SWCNT transistors are fabricated with high yield. This work will thus facilitate ongoing efforts to realize high-density SWCNT integrated circuits.

Organic transistors making use of room temperature ionic liquids as gating medium

NASA Astrophysics Data System (ADS)

Hoyos, Jonathan Javier Sayago

The ability to couple ionic and electronic transport in organic transistors, based on pi conjugated organic materials for the transistor channel, can be particularly interesting to achieve low voltage transistor operation, i.e. below 1 V. The operation voltage in typical organic transistors based on conventional dielectrics (200 nm thick SiO2) is commonly higher than 10 V. Electrolyte-gated (EG) transistors, i.e. employing an electrolyte as the gating medium, permit current modulations of several orders of magnitude at relatively low gate voltages thanks to the exceptionally high capacitance at the electrolyte/transistor channel interface, in turn due to the low thickness (ca. 3 nm) of the electrical double layers forming at the electrolyte/semiconductor interface. Electrolytes based on room temperature ionic liquids (RTILs) are promising in EG transistor applications for their high electrochemical stability and good ionic conductivity. The main motivation behind this work is to achieve low voltage operation in organic transistors by making use of RTILs as gating medium. First we demonstrate the importance of the gate electrode material in the EG transistor performance. The use of high surface area carbon gate electrodes limits undesirable electrochemical processes and renders unnecessary the presence of a reference electrode to monitor the channel potential. This was demonstrated using activated carbon as gate electrode, the electronic conducting polymer MEH-PPV, poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene vinylene] channel material, and the ionic liquid [EMIM][TFSI] (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide), as gating medium. Using high surface area gate electrodes resulted in sub-1 V operation and charge carrier mobilities of (1.0 +/- 0.5) x 10-2 cm2V -1s-1. A challenge in the field of EG transistors is to decrease their response time, a consequence of the slow ion redistribution in the transistor channel upon application of electric

Organic electrochemical transistors

NASA Astrophysics Data System (ADS)

Rivnay, Jonathan; Inal, Sahika; Salleo, Alberto; Owens, Róisín M.; Berggren, Magnus; Malliaras, George G.

2018-02-01

Organic electrochemical transistors (OECTs) make effective use of ion injection from an electrolyte to modulate the bulk conductivity of an organic semiconductor channel. The coupling between ionic and electronic charges within the entire volume of the channel endows OECTs with high transconductance compared with that of field-effect transistors, but also limits their response time. The synthetic tunability, facile deposition and biocompatibility of organic materials make OECTs particularly suitable for applications in biological interfacing, printed logic circuitry and neuromorphic devices. In this Review, we discuss the physics and the mechanism of operation of OECTs, focusing on their identifying characteristics. We highlight organic materials that are currently being used in OECTs and survey the history of OECT technology. In addition, form factors, fabrication technologies and applications such as bioelectronics, circuits and memory devices are examined. Finally, we take a critical look at the future of OECT research and development.

Magnetophoretic transistors in a tri-axial magnetic field.

PubMed

Abedini-Nassab, Roozbeh; Joh, Daniel Y; Albarghouthi, Faris; Chilkoti, Ashutosh; Murdoch, David M; Yellen, Benjamin B

2016-10-18

The ability to direct and sort individual biological and non-biological particles into spatially addressable locations is fundamentally important to the emerging field of single cell biology. Towards this goal, we demonstrate a new class of magnetophoretic transistors, which can switch single magnetically labeled cells and magnetic beads between different paths in a microfluidic chamber. Compared with prior work on magnetophoretic transistors driven by a two-dimensional in-plane rotating field, the addition of a vertical magnetic field bias provides significant advantages in preventing the formation of particle clumps and in better replicating the operating principles of circuits in general. However, the three-dimensional driving field requires a complete redesign of the magnetic track geometry and switching electrodes. We have solved this problem by developing several types of transistor geometries which can switch particles between two different tracks by either presenting a local energy barrier or by repelling magnetic objects away from a given track, hereby denoted as "barrier" and "repulsion" transistors, respectively. For both types of transistors, we observe complete switching of magnetic objects with currents of ∼40 mA, which is consistent over a range of particle sizes (8-15 μm). The switching efficiency was also tested at various magnetic field strengths (50-90 Oe) and driving frequencies (0.1-0.6 Hz); however, we again found that the device performance only weakly depended on these parameters. These findings support the use of these novel transistor geometries to form circuit architectures in which cells can be placed in defined locations and retrieved on demand.

Tunable organic transistors that use microfluidic source and drain electrodes

NASA Astrophysics Data System (ADS)

Maltezos, George; Nortrup, Robert; Jeon, Seokwoo; Zaumseil, Jana; Rogers, John A.

2003-09-01

This letter describes a type of transistor that uses conducting fluidic source and drain electrodes of mercury which flow on top of a thin film of the organic semiconductor pentacene. Pumping the mercury through suitably designed microchannels changes the width of the transistor channel and, therefore, the electrical characteristics of the device. Measurements on transistors with a range of channel lengths reveal low contact resistances between mercury and pentacene. Data collected before, during, and after pumping the mercury through the microchannels demonstrate reversible and systematic tuning of the devices. This unusual type of organic transistor has the potential to be useful in plastic microfluidic devices that require active elements for pumps, sensors, or other components. It also represents a noninvasive way to build transistor test structures that incorporate certain classes of chemically and mechanically fragile organic semiconductors.

Dual-gated MoS2/WSe2 van der Waals tunnel diodes and transistors.

PubMed

Roy, Tania; Tosun, Mahmut; Cao, Xi; Fang, Hui; Lien, Der-Hsien; Zhao, Peida; Chen, Yu-Ze; Chueh, Yu-Lun; Guo, Jing; Javey, Ali

2015-02-24

Two-dimensional layered semiconductors present a promising material platform for band-to-band-tunneling devices given their homogeneous band edge steepness due to their atomically flat thickness. Here, we experimentally demonstrate interlayer band-to-band tunneling in vertical MoS2/WSe2 van der Waals (vdW) heterostructures using a dual-gate device architecture. The electric potential and carrier concentration of MoS2 and WSe2 layers are independently controlled by the two symmetric gates. The same device can be gate modulated to behave as either an Esaki diode with negative differential resistance, a backward diode with large reverse bias tunneling current, or a forward rectifying diode with low reverse bias current. Notably, a high gate coupling efficiency of ∼80% is obtained for tuning the interlayer band alignments, arising from weak electrostatic screening by the atomically thin layers. This work presents an advance in the fundamental understanding of the interlayer coupling and electron tunneling in semiconductor vdW heterostructures with important implications toward the design of atomically thin tunnel transistors.

X-band T/R switch with body-floating multi-gate PDSOI NMOS transistors

NASA Astrophysics Data System (ADS)

Park, Mingyo; Min, Byung-Wook

2018-03-01

This paper presents an X-band transmit/receive switch using multi-gate NMOS transistors in a silicon-on-insulator CMOS process. For low loss and high power handling capability, floating body multi-gate NMOS transistors are adopted instead of conventional stacked NMOS transistors, resulting in 53% reduction of transistor area. Comparing to the stacked NMOS transistors, the multi gate transistor shares the source and drain region between stacked transistors, resulting in reduced chip area and parasitics. The impedance between bodies of gates in multi-gate NMOS transistors is assumed to be very large during design and confirmed after measurement. The measured input 1 dB compression point is 34 dBm. The measured insertion losses of TX and RX modes are respectively 1.7 dB and 2.0 dB at 11 GHz, and the measured isolations of TX and RX modes are >27 dB and >20 dB in X-band, respectively. The chip size is 0.086 mm2 without pads, which is 25% smaller than the T/R switch with stacked transistors.

A Klein-tunneling transistor with ballistic graphene

NASA Astrophysics Data System (ADS)

Wilmart, Quentin; Berrada, Salim; Torrin, David; Nguyen, V. Hung; Fève, Gwendal; Berroir, Jean-Marc; Dollfus, Philippe; Plaçais, Bernard

2014-06-01

Today, the availability of high mobility graphene up to room temperature makes ballistic transport in nanodevices achievable. In particular, p-n-p transistors in the ballistic regime give access to Klein tunneling physics and allow the realization of devices exploiting the optics-like behavior of Dirac Fermions (DFs) as in the Veselago lens or the Fabry-Pérot cavity. Here we propose a Klein tunneling transistor based on the geometrical optics of DFs. We consider the case of a prismatic active region delimited by a triangular gate, where total internal reflection may occur, which leads to the tunable suppression of transistor transmission. We calculate the transmission and the current by means of scattering theory and the finite bias properties using non-equilibrium Green's function (NEGF) simulation.

Top-gated chemical vapor deposition grown graphene transistors with current saturation.

PubMed

Bai, Jingwei; Liao, Lei; Zhou, Hailong; Cheng, Rui; Liu, Lixin; Huang, Yu; Duan, Xiangfeng

2011-06-08

Graphene transistors are of considerable interest for radio frequency (rf) applications. In general, transistors with large transconductance and drain current saturation are desirable for rf performance, which is however nontrivial to achieve in graphene transistors. Here we report high-performance top-gated graphene transistors based on chemical vapor deposition (CVD) grown graphene with large transconductance and drain current saturation. The graphene transistors were fabricated with evaporated high dielectric constant material (HfO(2)) as the top-gate dielectrics. Length scaling studies of the transistors with channel length from 5.6 μm to 100 nm show that complete current saturation can be achieved in 5.6 μm devices and the saturation characteristics degrade as the channel length shrinks down to the 100-300 nm regime. The drain current saturation was primarily attributed to drain bias induced shift of the Dirac points. With the selective deposition of HfO(2) gate dielectrics, we have further demonstrated a simple scheme to realize a 300 nm channel length graphene transistors with self-aligned source-drain electrodes to achieve the highest transconductance of 250 μS/μm reported in CVD graphene to date.

Duplex-imprinted nano well arrays for promising nanoparticle assembly

NASA Astrophysics Data System (ADS)

Li, Xiangping; Manz, Andreas

2018-02-01

A large area nano-duplex-imprint technique is presented in this contribution using natural cicada wings as stamps. The glassy wings of the cicada, which are abundant in nature, exhibit strikingly interesting nanopillar structures over their membrane. This technique, with excellent performance despite the nonplanar surface of the wings, combines both top-down and bottom-up nanofabrication techniques. It transitions micro-nanofabrication from a cleanroom environment to the bench. Two different materials, dicing tape with an acrylic layer and a UV optical adhesive, are used to make replications at the same time, thus achieving duplex imprinting. The promise of a large volume of commercial manufacturing of these nanostructure elements can be envisaged through this contribution to speeding up the fabrication process and achieving a higher throughput. The contact angle of the replicated nanowell arrays before and after oxygen plasma was measured. Gold nanoparticles (50 nm) were used to test how the nanoparticles behaved on the untreated and plasma-treated replica surface. The experiments show that promising nanoparticle self-assembly can be obtained.

Tunneling modulation of a quantum-well transistor laser

NASA Astrophysics Data System (ADS)

Feng, M.; Qiu, J.; Wang, C. Y.; Holonyak, N.

2016-11-01

Different than the Bardeen and Brattain transistor (1947) with the current gain depending on the ratio of the base carrier spontaneous recombination lifetime to the emitter-collector transit time, the Feng and Holonyak transistor laser current gain depends upon the base electron-hole (e-h) stimulated recombination, the base dielectric relaxation transport, and the collector stimulated tunneling. For the n-p-n transistor laser tunneling operation, the electron-hole pairs are generated at the collector junction under the influence of intra-cavity photon-assisted tunneling, with electrons drifting to the collector and holes drifting to the base. The excess charge in the base lowers the emitter junction energy barrier, allowing emitter electron injection into the base and satisfying charge neutrality via base dielectric relaxation transport (˜femtoseconds). The excess electrons near the collector junction undergo stimulated recombination at the base quantum-well or transport to the collector, thus supporting tunneling current amplification and optical modulation of the transistor laser.

Development and fabrication of an augmented power transistor

NASA Technical Reports Server (NTRS)

Geisler, M. J.; Hill, F. E.; Ostop, J. A.

1983-01-01

The development of device design and processing techniques for the fabrication of an augmented power transistor capable of fast switching and high voltage power conversion is discussed. The major device goals sustaining voltages in the range of 800 to 1000 V at 80 A and 50 A, respectively, at a gain of 14. The transistor switching rise and fall times were both to have been less than 0.5 microseconds. The development of a passivating glass technique to shield the device high voltage junction from moisture and ionic contaminants is discussed as well as the development of an isolated package that separates the thermal and electrical interfaces. A new method was found to alloy the transistors to the molybdenum disc at a relatively low temperature. The measured electrical performance compares well with the predicted optimum design specified in the original proposed design. A 40 mm diameter transistor was fabricated with seven times the emitter area of the earlier 23 mm diameter device.

Enhanced Amplification and Fan-Out Operation in an All-Magnetic Transistor

PubMed Central

Barman, Saswati; Saha, Susmita; Mondal, Sucheta; Kumar, Dheeraj; Barman, Anjan

2016-01-01

Development of all-magnetic transistor with favorable properties is an important step towards a new paradigm of all-magnetic computation. Recently, we showed such possibility in a Magnetic Vortex Transistor (MVT). Here, we demonstrate enhanced amplification in MVT achieved by introducing geometrical asymmetry in a three vortex sequence. The resulting asymmetry in core to core distance in the three vortex sequence led to enhanced amplification of the MVT output. A cascade of antivortices travelling in different trajectories including a nearly elliptical trajectory through the dynamic stray field is found to be responsible for this amplification. This asymmetric vortex transistor is further used for a successful fan-out operation, which gives large and nearly equal gains in two output branches. This large amplification in magnetic vortex gyration in magnetic vortex transistor is proposed to be maintained for a network of vortex transistor. The above observations promote the magnetic vortex transistors to be used in complex circuits and logic operations. PMID:27624662

In-situ high-pressure x-ray diffraction study of zinc ferrite nanoparticles

DOE PAGES

Ferrari, S.; Kumar, R. S.; Grinblat, F.; ...

2016-04-23

We have studied the high-pressure structural behavior of zinc ferrite (ZnFe 2O 4) nanoparticles by powder X-ray diffraction measurements up to 47 GPa. We found that the cubic spinel structure of ZnFe 2O 4 remains up to 33 GPa and a phase transition is induced beyond this pressure. The high-pressure phase is indexed to an orthorhombic CaMn 2O 4-type structure. Upon decompression the low- and high-pressure phases coexist. The compressibility of both structures was also investigated. We have observed that the lattice parameters of the high-pressure phase behave anisotropically upon compression. Further, we predict possible phase transition around 55 GPa.more » For comparison, we also studied the compression behavior of magnetite (Fe 3O 4) nanoparticles by X-ray diffraction up to 23 GPa. Spinel-type ZnFe 2O 4 and Fe 3O 4 nanoparticles have a bulk modulus of 172 (20) GPa and 152 (9) GPa, respectively. Lastly, this indicates that in both cases the nanoparticles do not undergo a Hall-Petch strengthening.« less

In-situ high-pressure x-ray diffraction study of zinc ferrite nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferrari, S.; Kumar, R. S.; Grinblat, F.

We have studied the high-pressure structural behavior of zinc ferrite (ZnFe 2O 4) nanoparticles by powder X-ray diffraction measurements up to 47 GPa. We found that the cubic spinel structure of ZnFe 2O 4 remains up to 33 GPa and a phase transition is induced beyond this pressure. The high-pressure phase is indexed to an orthorhombic CaMn 2O 4-type structure. Upon decompression the low- and high-pressure phases coexist. The compressibility of both structures was also investigated. We have observed that the lattice parameters of the high-pressure phase behave anisotropically upon compression. Further, we predict possible phase transition around 55 GPa.more » For comparison, we also studied the compression behavior of magnetite (Fe 3O 4) nanoparticles by X-ray diffraction up to 23 GPa. Spinel-type ZnFe 2O 4 and Fe 3O 4 nanoparticles have a bulk modulus of 172 (20) GPa and 152 (9) GPa, respectively. Lastly, this indicates that in both cases the nanoparticles do not undergo a Hall-Petch strengthening.« less

A Flush Toilet Model for the Transistor

NASA Astrophysics Data System (ADS)

Organtini, Giovanni

2012-04-01

In introductory physics textbooks, diodes working principles are usually well described in a relatively simple manner. According to our experience, they are well understood by students. Even when no formal derivation of the physics laws governing the current flow through a diode is given, the use of this device as a check valve is easily accepted. This is not true for transistors. In most textbooks the behavior of a transistor is given without formal explanation. When the amplification is computed, for some reason, students have difficulties in identifying the basic physical mechanisms that give rise to such an effect. In this paper we give a simple and captivating illustration of the working principles of a transistor as an amplifier, tailored to high school students even with almost no background in electronics nor in modern physics. We assume that the target audience is familiar with the idea that a diode works as a check valve for currents. The lecture emphasis is on the illustration of physics principles governing the behavior of a transistor, rather than on a formal description of the processes leading to amplification.

PH-Sensitive WO(3)-Based Microelectrochemical Transistors.

DTIC Science & Technology

1986-09-22

electronics, microelectrochemistry, microelectrodes, surface L- modification, molecuale based transistors, polyaniline , poly-3-methylthiophene Chemical...polymer, as in the cases of polypyrrole,8 poly(N-methyl pyrrole), 8b polyaniline , 9 or poly(3-methylthiophene),1 0 the polymer- % .4_. connected...Polypyrrole, 8 polyaniline , 9 and poly(3-methylthiophene) I0 are similar in that they are conducting when oxidized, and transistors based on these materials

Thin Film Transistors On Plastic Substrates

DOEpatents

Carey, Paul G.; Smith, Patrick M.; Sigmon, Thomas W.; Aceves, Randy C.

2004-01-20

A process for formation of thin film transistors (TFTs) on plastic substrates replaces standard thin film transistor fabrication techniques, and uses sufficiently lower processing temperatures so that inexpensive plastic substrates may be used in place of standard glass, quartz, and silicon wafer-based substrates. The silicon based thin film transistor produced by the process includes a low temperature substrate incapable of withstanding sustained processing temperatures greater than about 250.degree. C., an insulating layer on the substrate, a layer of silicon on the insulating layer having sections of doped silicon, undoped silicon, and poly-silicon, a gate dielectric layer on the layer of silicon, a layer of gate metal on the dielectric layer, a layer of oxide on sections of the layer of silicon and the layer of gate metal, and metal contacts on sections of the layer of silicon and layer of gate metal defining source, gate, and drain contacts, and interconnects.

Micellar Electrolytes in Organic Electrochemical Transistors

NASA Astrophysics Data System (ADS)

Cicoira, Fabio; Giuseppe, Tarabella; Nanda, Gaurav; Iannotta, Salvatore; Santato, Clara

2012-02-01

Organic electrochemical transistors (OECTs) are promising for applications in sensing and bioelectronics. OECTs consist of a conducting polymer film (transistor channel) in contact with an electrolyte. A gate electrode immersed in the electrolyte controls the doping/dedoping level of the conducting polymer. OECTs can be operated in aqueous electrolytes, making possible the implementation of organic electronic materials at the interface with biology. The inherent signal amplification of OECTs has the potential to yield sensors with low detection limits and high sensitivity. In this talk we will present recent studies on OECTs using ionic surfactants (such as hexadecyl-trimethyl-ammonium bromide) as electrolytes. As the conducting polymer we used PEDOT:PSS, i.e. (Poly,3-4 ethylenedioxythiopene) doped with Poly(styrene sulphonate). Interestingly, ionic surfactant electrolytes result in large transistor current modulation, especially beyond the critical micellar concentration (CMC). Since micelles play a primary role in biological processes and drug-delivery systems, the use for micellar electrolytes opens new exciting opportunities for the use of OECTs in bioelectronics.

A gallium phosphide high-temperature bipolar junction transistor

NASA Technical Reports Server (NTRS)

Zipperian, T. E.; Dawson, L. R.; Chaffin, R. J.

1981-01-01

Preliminary results are reported on the development of a high temperature (350 C) gallium phosphide bipolar junction transistor (BJT) for geothermal and other energy applications. This four-layer p(+)n(-)pp(+) structure was formed by liquid phase epitaxy using a supercooling technique to insure uniform nucleation of the thin layers. Magnesium was used as the p-type dopant to avoid excessive out-diffusion into the lightly doped base. By appropriate choice of electrodes, the device may also be driven as an n-channel junction field-effect transistor. The initial design suffers from a series resistance problem which limits the transistor's usefulness at high temperatures.

A novel paraplegia model in awake behaving macaques.

PubMed

Krucoff, Max O; Zhuang, Katie; MacLeod, David; Yin, Allen; Byun, Yoon Woo; Manson, Roberto Jose; Turner, Dennis A; Oliveira, Laura; Lebedev, Mikhail A

2017-09-01

Lower limb paralysis from spinal cord injury (SCI) or neurological disease carries a poor prognosis for recovery and remains a large societal burden. Neurophysiological and neuroprosthetic research have the potential to improve quality of life for these patients; however, the lack of an ethical and sustainable nonhuman primate model for paraplegia hinders their advancement. Therefore, our multidisciplinary team developed a way to induce temporary paralysis in awake behaving macaques by creating a fully implantable lumbar epidural catheter-subcutaneous port system that enables easy and reliable targeted drug delivery for sensorimotor blockade. During treadmill walking, aliquots of 1.5% lidocaine with 1:200,000 epinephrine were percutaneously injected into the ports of three rhesus macaques while surface electromyography (EMG) recorded muscle activity from their quadriceps and gastrocnemii. Diminution of EMG amplitude, loss of voluntary leg movement, and inability to bear weight were achieved for 60-90 min in each animal, followed by a complete recovery of function. The monkeys remained alert and cooperative during the paralysis trials and continued to take food rewards, and the ports remained functional after several months. This technique will enable recording from the cortex and/or spinal cord in awake behaving nonhuman primates during the onset, maintenance, and resolution of paraplegia for the first time, thus opening the door to answering basic neurophysiological questions about the acute neurological response to spinal cord injury and recovery. It will also negate the need to permanently injure otherwise high-value research animals for certain experimental paradigms aimed at developing and testing neural interface decoding algorithms for patients with lower extremity dysfunction. NEW & NOTEWORTHY A novel implantable lumbar epidural catheter-subcutaneous port system enables targeted drug delivery and induction of temporary paraplegia in awake, behaving nonhuman

A charged anisotropic well-behaved Adler-Finch-Skea solution satisfying Karmarkar condition

NASA Astrophysics Data System (ADS)

Bhar, Piyali; Singh, Ksh. Newton; Rahaman, Farook; Pant, Neeraj; Banerjee, Sumita

In the present paper, we discover a new well-behaved charged anisotropic solution of Einstein-Maxwell’s field equations. We ansatz the metric potential g00 of the form given by Maurya et al. (Eur. Phys. J. C 76(12) (2016) 693) with n = 2. In their paper, it is mentioned that for n = 2, the solution is not well-behaved for neutral configuration as the speed of sound is nondecreasing radially outward. However, the solution can represent a physically possible configuration with the inclusion of some net electric charge, i.e. the solution can become a well-behaved solution with decreasing sound speed radially outward for a charged configuration. Due to the inclusion of electric charge, the solution leads to a very stiff equation-of-state (EoS) with the velocity of sound at the center vr02 = 0.819, vt02 = 0.923 and the compactness parameter u = 0.823 is close to the Buchdahl limit 0.889. This stiff EoS support a compact star configuration of mass 5.418M⊙ and radius of 10.1km.

Transport Mechanisms in Organic Thin-Film Transistors

NASA Astrophysics Data System (ADS)

Fung, A. W. P.

1996-03-01

Recent success in fabricating field-effect transistors with polycrystalline α-sexithiophene (α-6T) has allowed us to study charge transport in this organic semiconductor. The appealing structural property that the oligomer chains are seated almost perpendicular to the substrate provides a model π-conjugated system which we find exhibits band transport at low temperatures. We observe a behavioral transition around 50K which is consistent with the metal-insulator transition in Holstein's small-polaron theory. The fact that we can observe intrinsic behavior means that the ambient-temperature mobility obtained in these transistors is optimal for α-6T. Agreement with the Holstein theory provides us with a prescription for rational design of materials for organic transistor applications. Work done in collaboration with L. Torsi, A. Dodabalapur, L. J. Rothberg and H. E. Katz.

Reprogrammable read only variable threshold transistor memory with isolated addressing buffer

DOEpatents

Lodi, Robert J.

1976-01-01

A monolithic integrated circuit, fully decoded memory comprises a rectangular array of variable threshold field effect transistors organized into a plurality of multi-bit words. Binary address inputs to the memory are decoded by a field effect transistor decoder into a plurality of word selection lines each of which activates an address buffer circuit. Each address buffer circuit, in turn, drives a word line of the memory array. In accordance with the word line selected by the decoder the activated buffer circuit directs reading or writing voltages to the transistors comprising the memory words. All of the buffer circuits additionally are connected to a common terminal for clearing all of the memory transistors to a predetermined state by the application to the common terminal of a large magnitude voltage of a predetermined polarity. The address decoder, the buffer and the memory array, as well as control and input/output control and buffer field effect transistor circuits, are fabricated on a common substrate with means provided to isolate the substrate of the address buffer transistors from the remainder of the substrate so that the bulk clearing function of simultaneously placing all of the memory transistors into a predetermined state can be performed.

Ion bipolar junction transistors

PubMed Central

Tybrandt, Klas; Larsson, Karin C.; Richter-Dahlfors, Agneta; Berggren, Magnus

2010-01-01

Dynamic control of chemical microenvironments is essential for continued development in numerous fields of life sciences. Such control could be achieved with active chemical circuits for delivery of ions and biomolecules. As the basis for such circuitry, we report a solid-state ion bipolar junction transistor (IBJT) based on conducting polymers and thin films of anion- and cation-selective membranes. The IBJT is the ionic analogue to the conventional semiconductor BJT and is manufactured using standard microfabrication techniques. Transistor characteristics along with a model describing the principle of operation, in which an anionic base current amplifies a cationic collector current, are presented. By employing the IBJT as a bioelectronic circuit element for delivery of the neurotransmitter acetylcholine, its efficacy in modulating neuronal cell signaling is demonstrated. PMID:20479274

Structure and Hydration of Highly-Branched, Monodisperse Phytoglycogen Nanoparticles

DOE PAGES

Nickels, Jonathan D.; Atkinson, John; Papp-Szabo, Erzsebet; ...

2016-01-30

Phytoglycogen is a naturally occurring polysaccharide nanoparticle made up of extensively branched glucose monomers. It has a number of unusual and advantageous properties, such as high water retention, low viscosity, and high stability in water, which make this biomaterial a promising candidate for a wide variety of applications. For this paper, we have characterized the structure and hydration of aqueous dispersions of phytoglycogen nanoparticles using neutron scattering. Small angle neutron scattering results suggest that the phytoglycogen nanoparticles behave similar to hard sphere colloids and are hydrated by a large number of water molecules (each nanoparticle contains between 250% and 285%more » of its mass in water). This suggests that phytoglycogen is an ideal sample in which to study the dynamics of hydration water. To this end, we used quasielastic neutron scattering (QENS) to provide an independent and consistent measure of the hydration number, and to estimate the retardation factor (or degree of water slow-down) for hydration water translational motions. These data demonstrate a length-scale dependence in the measured retardation factors that clarifies the origin of discrepancies between retardation factor values reported for hydration water using different experimental techniques. Finally, the present approach can be generalized to other systems containing nanoconfined water.« less

Failure rates for accelerated acceptance testing of silicon transistors

NASA Technical Reports Server (NTRS)

Toye, C. R.

1968-01-01

Extrapolation tables for the control of silicon transistor product reliability have been compiled. The tables are based on a version of the Arrhenius statistical relation and are intended to be used for low- and medium-power silicon transistors.

T-gate aligned nanotube radio frequency transistors and circuits with superior performance.

PubMed

Che, Yuchi; Lin, Yung-Chen; Kim, Pyojae; Zhou, Chongwu

2013-05-28

In this paper, we applied self-aligned T-gate design to aligned carbon nanotube array transistors and achieved an extrinsic current-gain cutoff frequency (ft) of 25 GHz, which is the best on-chip performance for nanotube radio frequency (RF) transistors reported to date. Meanwhile, an intrinsic current-gain cutoff frequency up to 102 GHz is obtained, comparable to the best value reported for nanotube RF transistors. Armed with the excellent extrinsic RF performance, we performed both single-tone and two-tone measurements for aligned nanotube transistors at a frequency up to 8 GHz. Furthermore, we utilized T-gate aligned nanotube transistors to construct mixing and frequency doubling analog circuits operated in gigahertz frequency regime. Our results confirm the great potential of nanotube-based circuit applications and indicate that nanotube transistors are promising building blocks in high-frequency electronics.

The strain and thermal induced tunable charging phenomenon in low power flexible memory arrays with a gold nanoparticle monolayer.

PubMed

Zhou, Ye; Han, Su-Ting; Xu, Zong-Xiang; Roy, V A L

2013-03-07

The strain and temperature dependent memory effect of organic memory transistors on plastic substrates has been investigated under ambient conditions. The gold (Au) nanoparticle monolayer was prepared and embedded in an atomic layer deposited aluminum oxide (Al(2)O(3)) as the charge trapping layer. The devices exhibited low operation voltage, reliable memory characteristics and long data retention time. Experimental analysis of the programming and erasing behavior at various bending states showed the relationship between strain and charging capacity. Thermal-induced effects on these memory devices have also been analyzed. The mobility shows ~200% rise and the memory window increases from 1.48 V to 1.8 V when the temperature rises from 20 °C to 80 °C due to thermally activated transport. The retention capability of the devices decreases with the increased working temperature. Our findings provide a better understanding of flexible organic memory transistors under various operating temperatures and validate their applications in various areas such as temperature sensors, temperature memory or advanced electronic circuits. Furthermore, the low temperature processing procedures of the key elements (Au nanoparticle monolayer and Al(2)O(3) dielectric layer) could be potentially integrated with large area flexible electronics.

AlN/GaN heterostructures for normally-off transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhuravlev, K. S., E-mail: zhur@isp.nsc.ru; Malin, T. V.; Mansurov, V. G.

The structure of AlN/GaN heterostructures with an ultrathin AlN barrier is calculated for normally-off transistors. The molecular-beam epitaxy technology of in situ passivated SiN/AlN/GaN heterostructures with a two-dimensional electron gas is developed. Normally-off transistors with a maximum current density of ~1 A/mm, a saturation voltage of 1 V, a transconductance of 350 mS/mm, and a breakdown voltage of more than 60 V are demonstrated. Gate lag and drain lag effects are almost lacking in these transistors.

BEHAVE: fire behavior prediction and fuel modeling system--FUEL subsystem

Treesearch

Robert E. Burgan; Richard C. Rothermel

1984-01-01

This manual documents the fuel modeling procedures of BEHAVE--a state-of-the-art wildland fire behavior prediction system. Described are procedures for collecting fuel data, using the data with the program, and testing and adjusting the fuel model.

Photolithographically Patterned TiO2 Films for Electrolyte-Gated Transistors.

PubMed

Valitova, Irina; Kumar, Prajwal; Meng, Xiang; Soavi, Francesca; Santato, Clara; Cicoira, Fabio

2016-06-15

Metal oxides constitute a class of materials whose properties cover the entire range from insulators to semiconductors to metals. Most metal oxides are abundant and accessible at moderate cost. Metal oxides are widely investigated as channel materials in transistors, including electrolyte-gated transistors, where the charge carrier density can be modulated by orders of magnitude upon application of relatively low electrical bias (2 V). Electrolyte gating offers the opportunity to envisage new applications in flexible and printed electronics as well as to improve our current understanding of fundamental processes in electronic materials, e.g. insulator/metal transitions. In this work, we employ photolithographically patterned TiO2 films as channels for electrolyte-gated transistors. TiO2 stands out for its biocompatibility and wide use in sensing, electrochromics, photovoltaics and photocatalysis. We fabricated TiO2 electrolyte-gated transistors using an original unconventional parylene-based patterning technique. By using a combination of electrochemical and charge carrier transport measurements we demonstrated that patterning improves the performance of electrolyte-gated TiO2 transistors with respect to their unpatterned counterparts. Patterned electrolyte-gated (EG) TiO2 transistors show threshold voltages of about 0.9 V, ON/OFF ratios as high as 1 × 10(5), and electron mobility above 1 cm(2)/(V s).

The Chemical Composition and Structure of Supported Sulfated Zirconia with Regulated Size Nanoparticles

NASA Astrophysics Data System (ADS)

Kanazhevskiy, V. V.; Shmachkova, V. P.; Kotsarenko, N. S.; Kochubey, D. I.; Vedrine, J. C.

2007-02-01

A set of model skeletal isomerization catalysts — sulfated zirconia nanoparticles of controlled thickness anchored on different supports — was prepared using colloidal solutions of Zr salt on titania as support. The nanoparticles of zirconia (1-5 nm) are epitaxially connected to the support surface, with S/Zr ratio equals to 1.3-1.5. It was shown by EXAFS that nanoparticles of non-stoichiometric zirconium sulfate Zr(SO4)1+x, where x<0.5, are formed on the support surface. Its structure looks like half-period shifted counterdirected chains built-up by zirconium atoms linked by triangle pyramids of sulfate groups. Considering catalytic data of skeletal n-butane isomerisation at 150°C, one can suggest that these species behave as the active component of sulfated zirconia. They are formed in subsurface layers as zirconium hydroxide undergoes sulfation followed by thermal treatment.

Investigation of the Ligand-Nanoparticle Interface: A Cryogenic Approach for Preserving Surface Chemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karakoti, Ajay S.; Yang, Ping; Wang, Weina

2018-02-15

Ligand functionalized nanoparticles have replaced bare nanoparticles from most biological applications. These applications require tight control over size and stability of nanoparticles in aqueous medium. Understanding the mechanism of interaction of nanoparticle surfaces with functional groups of different organic ligands such as carboxylic acids is confounding despite the two decades of research on nanoparticles because of the inability to characterize their surfaces in their immediate environment. Often the surface interaction is understood by correlating the information available, in a piecemeal approach, from surface sensitive spectroscopic information of ligands and the bulk and surface information of nanoparticles. In present study wemore » report the direct interaction of 5-7 nm cerium oxide nanoparticles surface with acetic acid. In-situ XPS study was carried out by freezing the aqueous solution of nanoparticles to liquid nitrogen temperatures. Analysis of data collected concurrently from the ligands as well as functionalized frozen cerium oxide nanoparticles show that the acetic acid binds to the ceria surface in both dissociated and molecular state with equal population over the surface. The cerium oxide surface was populated predominantly with Ce4+ ions consistent with the thermal hydrolysis synthesis. DFT calculations reveal that the acetate ions bind more strongly to the cerium oxide nanoparticles as compared to the water and can replace the hydration sphere of nanoparticles resulting in high acetate/acetic surface coverage. These findings reveal molecular level interaction between the nanoparticle surfaces and ligands giving a better understanding of how materials behave in their immediate aqueous environment. This study also proposes a simple and elegant methodology to directly study the surface functional groups attached to nanoparticles in their immediate aqueous environment.« less

Investigation of the Ligand–Nanoparticle Interface: A Cryogenic Approach for Preserving Surface Chemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karakoti, Ajay S.; Yang, Ping; Wang, Weina

Ligand functionalized nanoparticles have replaced bare nanoparticles from most biological applications. These applications require tight control over size and stability of nanoparticles in aqueous medium. Understanding the mechanism of interaction of nanoparticle surfaces with functional groups of different organic ligands such as carboxylic acids is confounding despite the two decades of research on nanoparticles because of the inability to characterize their surfaces in their immediate environment. Often the surface interaction is understood by correlating the information available, in a piecemeal approach, from surface sensitive spectroscopic information of ligands and the bulk and surface information of nanoparticles. In present study wemore » report the direct interaction of 5-7 nm cerium oxide nanoparticles surface with acetic acid. In-situ XPS study was carried out by freezing the aqueous solution of nanoparticles to liquid nitrogen temperatures. Analysis of data collected concurrently from the ligands as well as functionalized frozen cerium oxide nanoparticles show that the acetic acid binds to the ceria surface in both dissociated and molecular state with equal population over the surface. The cerium oxide surface was populated predominantly with Ce4+ ions consistent with the thermal hydrolysis synthesis. DFT calculations reveal that the acetate ions bind more strongly to the cerium oxide nanoparticles as compared to the water and can replace the hydration sphere of nanoparticles resulting in high acetate/acetic surface coverage. These findings reveal molecular level interaction between the nanoparticle surfaces and ligands giving a better understanding of how materials behave in their immediate aqueous environment. This study also proposes a simple and elegant methodology to directly study the surface functional groups attached to nanoparticles in their immediate aqueous environment.« less

Synthesis of Environmentally Friendly Highly Dispersed Magnetite Nanoparticles Based on Rosin Cationic Surfactants as Thin Film Coatings of Steel

PubMed Central

Atta, Ayman M.; El-Mahdy, Gamal A.; Al-Lohedan, Hamad A.; Al-Hussain, Sami A.

2014-01-01

This work presents a new method to prepare monodisperse magnetite nanoparticles capping with new cationic surfactants based on rosin. Core/shell type magnetite nanoparticles were synthesized using bis-N-(3-levopimaric maleic acid adduct-2-hydroxy) propyl-triethyl ammonium chloride (LPMQA) as capping agent. Fourier transform infrared spectroscopy (FTIR) was employed to characterize the nanoparticles chemical structure. Transmittance electron microscopies (TEM) and X-ray powder diffraction (XRD) were used to examine the morphology of the modified magnetite nanoparticles. The magnetite dispersed aqueous acid solution was evaluated as an effective anticorrosion behavior of a hydrophobic surface on steel. The inhibition effect of magnetite nanoparticles on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Results obtained from both potentiodynamic polarisation and EIS measurements reveal that the magnetite nanoparticle is an effective inhibitor for the corrosion of steel in 1.0 M HCl solution. Polarization data show that magnetite nanoparticles behave as a mixed type inhibitor. The inhibition efficiencies obtained from potentiodynamic polarization and EIS methods are in good agreement. PMID:24758936

Synthesis of environmentally friendly highly dispersed magnetite nanoparticles based on rosin cationic surfactants as thin film coatings of steel.

PubMed

Atta, Ayman M; El-Mahdy, Gamal A; Al-Lohedan, Hamad A; Al-Hussain, Sami A

2014-04-22

This work presents a new method to prepare monodisperse magnetite nanoparticles capping with new cationic surfactants based on rosin. Core/shell type magnetite nanoparticles were synthesized using bis-N-(3-levopimaric maleic acid adduct-2-hydroxy) propyl-triethyl ammonium chloride (LPMQA) as capping agent. Fourier transform infrared spectroscopy (FTIR) was employed to characterize the nanoparticles chemical structure. Transmittance electron microscopies (TEM) and X-ray powder diffraction (XRD) were used to examine the morphology of the modified magnetite nanoparticles. The magnetite dispersed aqueous acid solution was evaluated as an effective anticorrosion behavior of a hydrophobic surface on steel. The inhibition effect of magnetite nanoparticles on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Results obtained from both potentiodynamic polarisation and EIS measurements reveal that the magnetite nanoparticle is an effective inhibitor for the corrosion of steel in 1.0 M HCl solution. Polarization data show that magnetite nanoparticles behave as a mixed type inhibitor. The inhibition efficiencies obtained from potentiodynamic polarization and EIS methods are in good agreement.

Metal Oxide Silicon /MOS/ transistors protected from destructive damage by wire

NASA Technical Reports Server (NTRS)

Deboo, G. J.; Devine, E. J.

1966-01-01

Loop of flexible, small diameter, nickel wire protects metal oxide silicon /MOS/ transistors from a damaging electrostatic potential. The wire is attached to a music-wire spring, slipped over the MOS transistor case, and released so the spring tensions the wire loop around all the transistor leads, shorting them together. This allows handling without danger of damage.

Switching Characteristics of Ferroelectric Transistor Inverters

NASA Technical Reports Server (NTRS)

Laws, Crystal; Mitchell, Coey; MacLeod, Todd C.; Ho, Fat D.

2010-01-01

This paper presents the switching characteristics of an inverter circuit using a ferroelectric field effect transistor, FeFET. The propagation delay time characteristics, phl and plh are presented along with the output voltage rise and fall times, rise and fall. The propagation delay is the time-delay between the V50% transitions of the input and output voltages. The rise and fall times are the times required for the output voltages to transition between the voltage levels V10% and V90%. Comparisons are made between the MOSFET inverter and the ferroelectric transistor inverter.

Current-Induced Transistor Sensorics with Electrogenic Cells

PubMed Central

Fromherz, Peter

2016-01-01

The concepts of transistor recording of electroactive cells are considered, when the response is determined by a current-induced voltage in the electrolyte due to cellular activity. The relationship to traditional transistor recording, with an interface-induced response due to interactions with the open gate oxide, is addressed. For the geometry of a cell-substrate junction, the theory of a planar core-coat conductor is described with a one-compartment approximation. The fast electrical relaxation of the junction and the slow change of ion concentrations are pointed out. On that basis, various recording situations are considered and documented by experiments. For voltage-gated ion channels under voltage clamp, the effects of a changing extracellular ion concentration and the enhancement/depletion of ion conductances in the adherent membrane are addressed. Inhomogeneous ion conductances are crucial for transistor recording of neuronal action potentials. For a propagating action potential, the effects of an axon-substrate junction and the surrounding volume conductor are distinguished. Finally, a receptor-transistor-sensor is described, where the inhomogeneity of a ligand–activated ion conductance is achieved by diffusion of the agonist and inactivation of the conductance. Problems with regard to a development of reliable biosensors are mentioned. PMID:27120627

Free-Standing Self-Assemblies of Gallium Nitride Nanoparticles: A Review

DOE PAGES

Lan, Yucheng; Li, Jianye; Wong-Ng, Winnie; ...

2016-08-23

Gallium nitride (GaN) is an III-V semiconductor with a direct band-gap of 3.4eV . GaN has important potentials in white light-emitting diodes, blue lasers, and field effect transistors because of its super thermal stability and excellent optical properties, playing main roles in future lighting to reduce energy cost and sensors to resist radiations. GaN nanomaterials inherit bulk properties of the compound while possess novel photoelectric properties of nanomaterials. The review focuses on self-assemblies of GaN nanoparticles without templates, growth mechanisms of self-assemblies, and potential applications of the assembled nanostructures on renewable energy.

Low-frequency switching in a transistor amplifier.

PubMed

Carroll, T L

2003-04-01

It is known from extensive work with the diode resonator that the nonlinear properties of a P-N junction can lead to period doubling, chaos, and other complicated behaviors in a driven circuit. There has been very little work on what happens when more than one P-N junction is present. In this work, the first step towards multiple P-N junction circuits is taken by doing both experiments and simulations with a single-transistor amplifier using a bipolar transistor. Period doubling and chaos are seen when the amplifier is driven with signals between 100 kHz and 1 MHz, and they coincide with a very low frequency switching between different period doubled (or chaotic) wave forms. The switching frequencies are between 5 and 10 Hz. The switching behavior was confirmed in a simplified model of the transistor amplifier.

Molecular thermal transistor: Dimension analysis and mechanism

NASA Astrophysics Data System (ADS)

Behnia, S.; Panahinia, R.

2018-04-01

Recently, large challenge has been spent to realize high efficient thermal transistors. Outstanding properties of DNA make it as an excellent nano material in future technologies. In this paper, we introduced a high efficient DNA based thermal transistor. The thermal transistor operates when the system shows an increase in the thermal flux despite of decreasing temperature gradient. This is what called as negative differential thermal resistance (NDTR). Based on multifractal analysis, we could distinguish regions with NDTR state from non-NDTR state. Moreover, Based on dimension spectrum of the system, it is detected that NDTR state is accompanied by ballistic transport regime. The generalized correlation sum (analogous to specific heat) shows that an irregular decrease in the specific heat induces an increase in the mean free path (mfp) of phonons. This leads to the occurrence of NDTR.

Thermal transistor behavior of a harmonic chain

NASA Astrophysics Data System (ADS)

Kim, Sangrak

2017-09-01

Thermal transistor behavior of a harmonic chain with three heat reservoirs is explicitly analyzed. Temperature profile and heat currents of the rather general system are formulated and then heat currents for the simplest system are exactly calculated. The matrix connecting the three temperatures of the reservoirs and those of the particles comprises a stochastic matrix. The ratios R 1 and R 2 between heat currents, characterizing thermal signals can be expressed in terms of two external variables and two material parameters. It is shown that the ratios R 1 and R 2 can have wide range of real values. The thermal system shows a thermal transistor behavior such as the amplification of heat current by appropriately controlling the two variables and two parameters. We explicitly demonstrate the characteristics and mechanisms of thermal transistor with the simplest model.

A III-V nanowire channel on silicon for high-performance vertical transistors.

PubMed

Tomioka, Katsuhiro; Yoshimura, Masatoshi; Fukui, Takashi

2012-08-09

Silicon transistors are expected to have new gate architectures, channel materials and switching mechanisms in ten years' time. The trend in transistor scaling has already led to a change in gate structure from two dimensions to three, used in fin field-effect transistors, to avoid problems inherent in miniaturization such as high off-state leakage current and the short-channel effect. At present, planar and fin architectures using III-V materials, specifically InGaAs, are being explored as alternative fast channels on silicon because of their high electron mobility and high-quality interface with gate dielectrics. The idea of surrounding-gate transistors, in which the gate is wrapped around a nanowire channel to provide the best possible electrostatic gate control, using InGaAs channels on silicon, however, has been less well investigated because of difficulties in integrating free-standing InGaAs nanostructures on silicon. Here we report the position-controlled growth of vertical InGaAs nanowires on silicon without any buffering technique and demonstrate surrounding-gate transistors using InGaAs nanowires and InGaAs/InP/InAlAs/InGaAs core-multishell nanowires as channels. Surrounding-gate transistors using core-multishell nanowire channels with a six-sided, high-electron-mobility transistor structure greatly enhance the on-state current and transconductance while keeping good gate controllability. These devices provide a route to making vertically oriented transistors for the next generation of field-effect transistors and may be useful as building blocks for wireless networks on silicon platforms.

Development and Experimental Evaluation of an Automated Multi-Media Course on Transistors.

ERIC Educational Resources Information Center

Whitted, J.H., Jr.; And Others

A completely automated multi-media self-study program for teaching a portion of electronic solid-state fundamentals was developed. The subject matter areas included were fundamental theory of transistors, transistor amplifier fundamentals, and simple mathematical analysis of transistors including equivalent circuits, parameters, and characteristic…

PH Sensitive WO3-Based Microelectrochemical Transistors.

DTIC Science & Technology

1986-09-22

molecular electronics, microelectrochemistr microelectrodes, sur ace modtfication, molecule-based transistors, .... " polyaniline , poly-3-methylthiophene...polypyrrole,8 poly(N-methyl pyrrole),8b polyaniline , 9 or poly(3-methylthiophene),1 0 the polymer- ’-p2 ’ -p " ; , Q ’ , : ’ ’ ’ ... , , ’ i connected...VD. Polypyrrole, 8 polyaniline , 9 and poly(3-methylthiophene)1 0 are similar in that they are conducting when oxidized, and transistors based on these

Lifetime prediction of InGaZnO thin film transistor for the application of display device and BEOL-transistors

NASA Astrophysics Data System (ADS)

Kim, Sang Min; Cho, Won Ju; Yu, Chong Gun; Park, Jong Tae

2018-04-01

In this work, the lifetime prediction models of amorphous InGaZnO thin film transistors (a-IGZO TFTs) were suggested for the application of display device and BEOL (Back End Of line) transistors with embedded a-IGZO TFTs. Four different types of test devices according to the active layer thickness, source/drain electrode materials and thermal treatments have been used to verify the suggested model. The device lifetimes under high gate bias stress and hot carrier stress were extracted through fittings of the stretched-exponential equation for threshold voltage shifts and the current estimation method for drain current degradations. Our suggested lifetime prediction models could be used in any kinds of structures of a-IGZO TFTs for the application of display device and BEOL transistors. The a-IGZO TFTs with embedded ITO local conducting layer under source/drain is better for BEOL transistor application and a-IGZO TFTs with InGaZnO thin film as source/drain electrodes may be better for the application of display devices. From 1983 to 1985, he was a Researcher at Gold-Star Semiconductor, Inc., Korea, where he worked on the development of SRAM. He joined the Department of Electronics Engineering, University of Incheon, Incheon, Korea, in 1987, where he is a Professor. As a visiting scientist at Massachusetts Institute of Technology, Cambridge, in 1991, he conducted research in hot carrier reliability of CMOS. As a visiting scholar at University of California, Davis, in 2001, he conducted research on the device structure of Nano-scale SOI CMOS. His recent interests are device structure and reliability of Nano-scale CMOS devices, flash memory, and thin film transistors.

Scaling of Device Variability and Subthreshold Swing in Ballistic Carbon Nanotube Transistors

NASA Astrophysics Data System (ADS)

Cao, Qing; Tersoff, Jerry; Han, Shu-Jen; Penumatcha, Ashish V.

2015-08-01

In field-effect transistors, the inherent randomness of dopants and other charges is a major cause of device-to-device variability. For a quasi-one-dimensional device such as carbon nanotube transistors, even a single charge can drastically change the performance, making this a critical issue for their adoption as a practical technology. Here we calculate the effect of the random charges at the gate-oxide surface in ballistic carbon nanotube transistors, finding good agreement with the variability statistics in recent experiments. A combination of experimental and simulation results further reveals that these random charges are also a major factor limiting the subthreshold swing for nanotube transistors fabricated on thin gate dielectrics. We then establish that the scaling of the nanotube device uniformity with the gate dielectric, fixed-charge density, and device dimension is qualitatively different from conventional silicon transistors, reflecting the very different device physics of a ballistic transistor with a quasi-one-dimensional channel. The combination of gate-oxide scaling and improved control of fixed-charge density should provide the uniformity needed for large-scale integration of such novel one-dimensional transistors even at extremely scaled device dimensions.

Pseudo 2-transistor active pixel sensor using an n-well/gate-tied p-channel metal oxide semiconductor field eeffect transistor-type photodetector with built-in transfer gate

NASA Astrophysics Data System (ADS)

Seo, Sang-Ho; Seo, Min-Woong; Kong, Jae-Sung; Shin, Jang-Kyoo; Choi, Pyung

2008-11-01

In this paper, a pseudo 2-transistor active pixel sensor (APS) has been designed and fabricated by using an n-well/gate-tied p-channel metal oxide semiconductor field effect transistor (PMOSFET)-type photodetector with built-in transfer gate. The proposed sensor has been fabricated using a 0.35 μm 2-poly 4-metal standard complementary metal oxide semiconductor (CMOS) logic process. The pseudo 2-transistor APS consists of two NMOSFETs and one photodetector which can amplify the generated photocurrent. The area of the pseudo 2-transistor APS is 7.1 × 6.2 μm2. The sensitivity of the proposed pixel is 49 lux/(V·s). By using this pixel, a smaller pixel area and a higher level of sensitivity can be realized when compared with a conventional 3-transistor APS which uses a pn junction photodiode.

Laser direct writing and inkjet printing for a sub-2 μm channel length MoS2 transistor with high-resolution electrodes

NASA Astrophysics Data System (ADS)

Kwon, Hyuk-Jun; Chung, Seungjun; Jang, Jaewon; Grigoropoulos, Costas P.

2016-10-01

Patterns formed by the laser direct writing (LDW) lithography process are used either as channels or barriers for MoS2 transistors fabricated via inkjet printing. Silver (Ag) nanoparticle ink is printed over patterns formed on top of the MoS2 flakes in order to construct high-resolution source/drain (S/D) electrodes. When positive photoresist is used, the produced grooves are filled with inkjetted Ag ink by capillary forces. On the other hand, in the case of negative photoresist, convex barrier-like patterns are written on the MoS2 flakes and patterns, dividing the printed Ag ink into the S/D electrodes by self-alignment. LDW lithography combined with inkjet printing is applied to MoS2 thin-film transistors that exhibit moderate electrical performance such as mobility and subthreshold swing. However, especially in the linear operation regime, their features are limited by the contact effect. The Y-function method can exclude the contact effect and allow proper evaluation of the maximum available mobility and contact resistance. The presented fabrication methods may facilitate the development of cost-effective fabrication processes.

Radio-frequency Bloch-transistor electrometer.

PubMed

Zorin, A B

2001-04-09

A quantum electrometer is proposed which is based on charge modulation of the Josephson supercurrent in the Bloch transistor inserted in a superconducting ring. As this ring is inductively coupled to a high- Q resonance tank circuit, the variations of the charge on the transistor island are converted into variations of amplitude and phase of oscillations in the tank. These variations are amplified and then detected. At sufficiently low temperature of the tank the device sensitivity is determined by the energy resolution of the amplifier, that can be reduced down to the standard quantum limit of 1 / 2Planck's over 2pi. A "back-action-evading" scheme of subquantum limit measurements is proposed.

Monolithic acoustic graphene transistors based on lithium niobate thin film

NASA Astrophysics Data System (ADS)

Liang, J.; Liu, B.-H.; Zhang, H.-X.; Zhang, H.; Zhang, M.-L.; Zhang, D.-H.; Pang, W.

2018-05-01

This paper introduces an on-chip acoustic graphene transistor based on lithium niobate thin film. The graphene transistor is embedded in a microelectromechanical systems (MEMS) acoustic wave device, and surface acoustic waves generated by the resonator induce a macroscopic current in the graphene due to the acousto-electric (AE) effect. The acoustic resonator and the graphene share the lithium niobate film, and a gate voltage is applied through the back side of the silicon substrate. The AE current induced by the Rayleigh and Sezawa modes was investigated, and the transistor outputs a larger current in the Rayleigh mode because of a larger coupling to velocity ratio. The output current increases linearly with the input radiofrequency power and can be effectively modulated by the gate voltage. The acoustic graphene transistor realized a five-fold enhancement in the output current at an optimum gate voltage, outperforming its counterpart with a DC input. The acoustic graphene transistor demonstrates a paradigm for more-than-Moore technology. By combining the benefits of MEMS and graphene circuits, it opens an avenue for various system-on-chip applications.

DEVICE TECHNOLOGY. Nanomaterials in transistors: From high-performance to thin-film applications.

PubMed

Franklin, Aaron D

2015-08-14

For more than 50 years, silicon transistors have been continuously shrunk to meet the projections of Moore's law but are now reaching fundamental limits on speed and power use. With these limits at hand, nanomaterials offer great promise for improving transistor performance and adding new applications through the coming decades. With different transistors needed in everything from high-performance servers to thin-film display backplanes, it is important to understand the targeted application needs when considering new material options. Here the distinction between high-performance and thin-film transistors is reviewed, along with the benefits and challenges to using nanomaterials in such transistors. In particular, progress on carbon nanotubes, as well as graphene and related materials (including transition metal dichalcogenides and X-enes), outlines the advances and further research needed to enable their use in transistors for high-performance computing, thin films, or completely new technologies such as flexible and transparent devices. Copyright © 2015, American Association for the Advancement of Science.

Dual-mode operation of 2D material-base hot electron transistors

PubMed Central

Lan, Yann-Wen; Torres, Jr., Carlos M.; Zhu, Xiaodan; Qasem, Hussam; Adleman, James R.; Lerner, Mitchell B.; Tsai, Shin-Hung; Shi, Yumeng; Li, Lain-Jong; Yeh, Wen-Kuan; Wang, Kang L.

2016-01-01

Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (VCB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (VCB < 0). That is, our 2D material-base hot electron transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications. PMID:27581550

Dual-mode operation of 2D material-base hot electron transistors.

PubMed

Lan, Yann-Wen; Torres, Carlos M; Zhu, Xiaodan; Qasem, Hussam; Adleman, James R; Lerner, Mitchell B; Tsai, Shin-Hung; Shi, Yumeng; Li, Lain-Jong; Yeh, Wen-Kuan; Wang, Kang L

2016-09-01

Vertical hot electron transistors incorporating atomically-thin 2D materials, such as graphene or MoS2, in the base region have been proposed and demonstrated in the development of electronic and optoelectronic applications. To the best of our knowledge, all previous 2D material-base hot electron transistors only considered applying a positive collector-base potential (VCB > 0) as is necessary for the typical unipolar hot-electron transistor behavior. Here we demonstrate a novel functionality, specifically a dual-mode operation, in our 2D material-base hot electron transistors (e.g. with either graphene or MoS2 in the base region) with the application of a negative collector-base potential (VCB < 0). That is, our 2D material-base hot electron transistors can operate in either a hot-electron or a reverse-current dominating mode depending upon the particular polarity of VCB. Furthermore, these devices operate at room temperature and their current gains can be dynamically tuned by varying VCB. We anticipate our multi-functional dual-mode transistors will pave the way towards the realization of novel flexible 2D material-based high-density and low-energy hot-carrier electronic applications.

Back bias induced dynamic and steep subthreshold swing in junctionless transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parihar, Mukta Singh; Kranti, Abhinav, E-mail: akranti@iiti.ac.in

In this work, we analyze back bias induced steep and dynamic subthreshold swing in junctionless double gate transistors operated in the asymmetric mode. This impact ionization induced dynamic subthreshold swing is explained in terms of the ratio between minimum hole concentration and peak electron concentration, and the dynamic change in the location of the conduction channel with applied front gate voltage. The reason for the occurrence of impact ionization at sub-bandgap drain voltages in silicon junctionless transistors is also accounted for. The optimum junctionless transistor operating at a back gate bias of −0.9 V, achieves over 5 orders of change inmore » drain current at a gate overdrive of 200 mV and drain bias of 1 V. These results for junctionless transistors are significantly better than those exhibited by silicon tunnel field effect transistors operating at the same drain bias.« less

High-performance carbon nanotube thin-film transistors on flexible paper substrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Na; Yun, Ki Nam; Yu, Hyun-Yong

Single-walled carbon nanotubes (SWCNTs) are promising materials as active channels for flexible transistors owing to their excellent electrical and mechanical properties. However, flexible SWCNT transistors have never been realized on paper substrates, which are widely used, inexpensive, and recyclable. In this study, we fabricated SWCNT thin-film transistors on photo paper substrates. The devices exhibited a high on/off current ratio of more than 10{sup 6} and a field-effect mobility of approximately 3 cm{sup 2}/V·s. The proof-of-concept demonstration indicates that SWCNT transistors on flexible paper substrates could be applied as low-cost and recyclable flexible electronics.

Ferroelectric field-effect transistors based on solution-processed electrochemically exfoliated graphene

NASA Astrophysics Data System (ADS)

Heidler, Jonas; Yang, Sheng; Feng, Xinliang; Müllen, Klaus; Asadi, Kamal

2018-06-01

Memories based on graphene that could be mass produced using low-cost methods have not yet received much attention. Here we demonstrate graphene ferroelectric (dual-gate) field effect transistors. The graphene has been obtained using electrochemical exfoliation of graphite. Field-effect transistors are realized using a monolayer of graphene flakes deposited by the Langmuir-Blodgett protocol. Ferroelectric field effect transistor memories are realized using a random ferroelectric copolymer poly(vinylidenefluoride-co-trifluoroethylene) in a top gated geometry. The memory transistors reveal ambipolar behaviour with both electron and hole accumulation channels. We show that the non-ferroelectric bottom gate can be advantageously used to tune the on/off ratio.

Floating gate transistors as biosensors (Conference Presentation)

NASA Astrophysics Data System (ADS)

Frisbie, C. Daniel

2016-11-01

Electrolyte gated transistors (EGTs) are a sub-class of thin film transistors that are extremely promising for biological sensing applications. These devices employ a solid electrolyte as the gate insulator; the very large capacitance of the electrolyte results in low voltage operation and high transconductance or gain. This talk will describe the fabrication of floating gate EGTs and their use as ricin sensors. The critical performance metrics for EGTs compared with other types of TFTs will also be reviewed.

Transistor Laser Optical NOR Gate for High Speed Optical Logic Processors

DTIC Science & Technology

2017-03-20

proposes an optical bistable latch can be built with two universal photonic NOR gate circuits, which are implemented by the three-port tunneling ... Tunneling Junction Transistor Laser (TJ-TL); Optical NOR Gate. Introduction To fulfill the future national security and intelligence needs in this...two-terminal diode lasers. Three-Port Transistor Laser – an Integration of Quantum-Wells into Heterojunction Bipolar Transistor Different than

Transport spectroscopy of coupled donors in silicon nano-transistors

PubMed Central

Moraru, Daniel; Samanta, Arup; Anh, Le The; Mizuno, Takeshi; Mizuta, Hiroshi; Tabe, Michiharu

2014-01-01

The impact of dopant atoms in transistor functionality has significantly changed over the past few decades. In downscaled transistors, discrete dopants with uncontrolled positions and number induce fluctuations in device operation. On the other hand, by gaining access to tunneling through individual dopants, a new type of devices is developed: dopant-atom-based transistors. So far, most studies report transport through dopants randomly located in the channel. However, for practical applications, it is critical to control the location of the donors with simple techniques. Here, we fabricate silicon transistors with selectively nanoscale-doped channels using nano-lithography and thermal-diffusion doping processes. Coupled phosphorus donors form a quantum dot with the ground state split into a number of levels practically equal to the number of coupled donors, when the number of donors is small. Tunneling-transport spectroscopy reveals fine features which can be correlated with the different numbers of donors inside the quantum dot, as also suggested by first-principles simulation results. PMID:25164032

Interactions between suspension characteristics and physicochemical properties of silver and copper oxide nanoparticles: a case study for optimizing nanoparticle stock suspensions using a central composite design.

PubMed

Son, Jino; Vavra, Janna; Li, Yusong; Seymour, Megan; Forbes, Valery

2015-04-01

The preparation of a stable nanoparticle stock suspension is the first step in nanotoxicological studies, but how different preparation methods influence the physicochemical properties of nanoparticles in a solution, even in Milli-Q water, is often under-appreciated. In this study, a systematic approach using a central composite design (CCD) was employed to investigate the effects of sonication time and suspension concentration on the physicochemical properties (i.e. hydrodynamic diameter, zeta potential and ion dissolution) of silver (Ag) and copper oxide (CuO) nanoparticles (NPs) and to identify optimal conditions for suspension preparation in Milli-Q water; defined as giving the smallest particle sizes, highest suspension stability and lowest ion dissolution. Indeed, all the physicochemical properties of AgNPs and CuONPs varied dramatically depending on how the stock suspensions were prepared and differed profoundly between nanoparticle types, indicating the importance of suspension preparation. Moreover, the physicochemical properties of AgNPs and CuONPs, at least in simple media (Milli-Q water), behaved in predictable ways as a function of sonication time and suspension concentration, confirming the validity of our models. Overall, the approach allows systematic assessment of the influence of various factors on key properties of nanoparticle suspensions, which will facilitate optimization of the preparation of nanoparticle stock suspensions and improve the reproducibility of nanotoxicological results. We recommend that further attention be given to details of stock suspension preparation before conducting nanotoxicological studies as these can have an important influence on the behavior and subsequent toxicity of nanoparticles. Copyright © 2014 Elsevier Ltd. All rights reserved.

Magnon transistor for all-magnon data processing.

PubMed

Chumak, Andrii V; Serga, Alexander A; Hillebrands, Burkard

2014-08-21

An attractive direction in next-generation information processing is the development of systems employing particles or quasiparticles other than electrons--ideally with low dissipation--as information carriers. One such candidate is the magnon: the quasiparticle associated with the eigen-excitations of magnetic materials known as spin waves. The realization of single-chip all-magnon information systems demands the development of circuits in which magnon currents can be manipulated by magnons themselves. Using a magnonic crystal--an artificial magnetic material--to enhance nonlinear magnon-magnon interactions, we have succeeded in the realization of magnon-by-magnon control, and the development of a magnon transistor. We present a proof of concept three-terminal device fabricated from an electrically insulating magnetic material. We demonstrate that the density of magnons flowing from the transistor's source to its drain can be decreased three orders of magnitude by the injection of magnons into the transistor's gate.

Transistor-based filter for inhibiting load noise from entering a power supply

DOEpatents

Taubman, Matthew S

2013-07-02

A transistor-based filter for inhibiting load noise from entering a power supply is disclosed. The filter includes a first transistor having an emitter coupled to a power supply, a collector coupled to a load, and a base. The filter also includes a first capacitor coupled between the base of the first transistor and a ground terminal. The filter further includes an impedance coupled between the base and a node between the collector and the load, or a second transistor and second capacitor. The impedance can be a resistor or an inductor.

Transistor-based filter for inhibiting load noise from entering a power supply

DOEpatents

Taubman, Matthew S

2015-02-24

A transistor-based filter for inhibiting load noise from entering a power supply is disclosed. The filter includes a first transistor having an emitter coupled to a power supply, a collector coupled to a load, and a base. The filter also includes a first capacitor coupled between the base of the first transistor and a ground terminal The filter further includes an impedance coupled between the base and a node between the collector and the load, or a second transistor and second capacitor. The impedance can be a resistor or an inductor.

Study of static and dynamic magnetic properties of Fe nanoparticles composited with activated carbon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pal, Satyendra Prakash, E-mail: sppal85@gmail.com; Department of Physical Sciences, Indian Institute of Science Education and Research, Mohali, Knowledge city, Sector81, SAS Nagar, Manauli-140306, Punjab; Kaur, Guratinder

2016-05-23

Nanocomposite of Fe nanoparticles with activated carbon has been synthesized to alter the magnetic spin-spin interaction and hence study the dilution effect on the static and dynamic magnetic properties of the Fe nanoparticle system. Transmission electron microscopic (TEM) image shows the spherical Fe nanoparticles dispersed in carbon matrix with 13.8 nm particle size. Temperature dependent magnetization measurement does not show any blocking temperature at all, right up to the room temperature. Magnetic hysteresis curve, taken at 300 K, shows small value of the coercivity and this small hysteresis indicates the presence of an energy barrier and inherent magnetization dynamics. Langevinmore » function fitting of the hysteresis curve gives almost similar value of particle size as obtained from TEM analysis. Magnetic relaxation data, taken at a temperature of 100 K, were fitted with a combination of two exponentially decaying function. This diluted form of nanoparticle system, which has particles size in the superparamagnetic limit, behaves like a dilute ensemble of superspins with large value of the magnetic anisotropic barrier.« less

Analogy of transistor function with modulating photonic band gap in electromagnetically induced grating

PubMed Central

Wang, Zhiguo; Ullah, Zakir; Gao, Mengqin; Zhang, Dan; Zhang, Yiqi; Gao, Hong; Zhang, Yanpeng

2015-01-01

Optical transistor is a device used to amplify and switch optical signals. Many researchers focus on replacing current computer components with optical equivalents, resulting in an optical digital computer system processing binary data. Electronic transistor is the fundamental building block of modern electronic devices. To replace electronic components with optical ones, an equivalent optical transistor is required. Here we compare the behavior of an optical transistor with the reflection from a photonic band gap structure in an electromagnetically induced transparency medium. A control signal is used to modulate the photonic band gap structure. Power variation of the control signal is used to provide an analogy between the reflection behavior caused by modulating the photonic band gap structure and the shifting of Q-point (Operation point) as well as amplification function of optical transistor. By means of the control signal, the switching function of optical transistor has also been realized. Such experimental schemes could have potential applications in making optical diode and optical transistor used in quantum information processing. PMID:26349444

Analogy of transistor function with modulating photonic band gap in electromagnetically induced grating

NASA Astrophysics Data System (ADS)

Wang, Zhiguo; Ullah, Zakir; Gao, Mengqin; Zhang, Dan; Zhang, Yiqi; Gao, Hong; Zhang, Yanpeng

2015-09-01

Optical transistor is a device used to amplify and switch optical signals. Many researchers focus on replacing current computer components with optical equivalents, resulting in an optical digital computer system processing binary data. Electronic transistor is the fundamental building block of modern electronic devices. To replace electronic components with optical ones, an equivalent optical transistor is required. Here we compare the behavior of an optical transistor with the reflection from a photonic band gap structure in an electromagnetically induced transparency medium. A control signal is used to modulate the photonic band gap structure. Power variation of the control signal is used to provide an analogy between the reflection behavior caused by modulating the photonic band gap structure and the shifting of Q-point (Operation point) as well as amplification function of optical transistor. By means of the control signal, the switching function of optical transistor has also been realized. Such experimental schemes could have potential applications in making optical diode and optical transistor used in quantum information processing.

Transistor analogs of emergent iono-neuronal dynamics.

PubMed

Rachmuth, Guy; Poon, Chi-Sang

2008-06-01

Neuromorphic analog metal-oxide-silicon (MOS) transistor circuits promise compact, low-power, and high-speed emulations of iono-neuronal dynamics orders-of-magnitude faster than digital simulation. However, their inherently limited input voltage dynamic range vs power consumption and silicon die area tradeoffs makes them highly sensitive to transistor mismatch due to fabrication inaccuracy, device noise, and other nonidealities. This limitation precludes robust analog very-large-scale-integration (aVLSI) circuits implementation of emergent iono-neuronal dynamics computations beyond simple spiking with limited ion channel dynamics. Here we present versatile neuromorphic analog building-block circuits that afford near-maximum voltage dynamic range operating within the low-power MOS transistor weak-inversion regime which is ideal for aVLSI implementation or implantable biomimetic device applications. The fabricated microchip allowed robust realization of dynamic iono-neuronal computations such as coincidence detection of presynaptic spikes or pre- and postsynaptic activities. As a critical performance benchmark, the high-speed and highly interactive iono-neuronal simulation capability on-chip enabled our prompt discovery of a minimal model of chaotic pacemaker bursting, an emergent iono-neuronal behavior of fundamental biological significance which has hitherto defied experimental testing or computational exploration via conventional digital or analog simulations. These compact and power-efficient transistor analogs of emergent iono-neuronal dynamics open new avenues for next-generation neuromorphic, neuroprosthetic, and brain-machine interface applications.

Ultrathin strain-gated field effect transistor based on In-doped ZnO nanobelts

NASA Astrophysics Data System (ADS)

Zhang, Zheng; Du, Junli; Li, Bing; Zhang, Shuhao; Hong, Mengyu; Zhang, Xiaomei; Liao, Qingliang; Zhang, Yue

2017-08-01

In this work, we fabricated a strain-gated piezoelectric transistor based on single In-doped ZnO nanobelt with ±(0001) top/bottom polar surfaces. In the vertical structured transistor, the Pt tip of the AFM and Au film are used as source and drain electrode. The electrical transport performance of the transistor is gated by compressive strains. The working mechanism is attributed to the Schottky barrier height changed under the coupling effect of piezoresistive and piezoelectric. Uniquely, the transistor turns off under the compressive stress of 806 nN. The strain-gated transistor is likely to have important applications in high resolution mapping device and MEMS devices.

A Novel Metal-Ferroelectric-Semiconductor Field-Effect Transistor Memory Cell Design

NASA Technical Reports Server (NTRS)

Phillips, Thomas A.; Bailey, Mark; Ho, Fat Duen

2004-01-01

The use of a Metal-Ferroelectric-Semiconductor Field-Effect Transistor (MFSFET) in a resistive-load SRAM memory cell has been investigated A typical two-transistor resistive-load SRAM memory cell architecture is modified by replacing one of the NMOS transistors with an n-channel MFSFET. The gate of the MFSFET is connected to a polling voltage pulse instead of the other NMOS transistor drain. The polling voltage pulses are of sufficient magnitude to saturate the ferroelectric gate material and force the MFSFET into a particular logic state. The memory cell circuit is further modified by the addition of a PMOS transistor and a load resistor in order to improve the retention characteristics of the memory cell. The retention characteristics of both the "1" and "0" logic states are simulated. The simulations show that the MFSFET memory cell design can maintain both the "1" and "0" logic states for a long period of time.

Osteoblastic cells trigger gate currents on nanocrystalline diamond transistor.

PubMed

Izak, Tibor; Krátká, Marie; Kromka, Alexander; Rezek, Bohuslav

2015-05-01

We show the influence of osteoblastic SAOS-2 cells on the transfer characteristics of nanocrystalline diamond solution-gated field-effect transistors (SGFET) prepared on glass substrates. Channels of these fully transparent SGFETs are realized by hydrogen termination of undoped diamond film. After cell cultivation, the transistors exhibit about 100× increased leakage currents (up to 10nA). During and after the cell delamination, the transistors return to original gate currents. We propose a mechanism where this triggering effect is attributed to ions released from adhered cells, which depends on the cell adhesion morphology, and could be used for cell culture monitoring. Copyright © 2015 Elsevier B.V. All rights reserved.

Controlling charge current through a DNA based molecular transistor

NASA Astrophysics Data System (ADS)

Behnia, S.; Fathizadeh, S.; Ziaei, J.

2017-01-01

Molecular electronics is complementary to silicon-based electronics and may induce electronic functions which are difficult to obtain with conventional technology. We have considered a DNA based molecular transistor and study its transport properties. The appropriate DNA sequence as a central chain in molecular transistor and the functional interval for applied voltages is obtained. I-V characteristic diagram shows the rectifier behavior as well as the negative differential resistance phenomenon of DNA transistor. We have observed the nearly periodic behavior in the current flowing through DNA. It is reported that there is a critical gate voltage for each applied bias which above it, the electrical current is always positive.

Acoustic transistor: Amplification and switch of sound by sound

NASA Astrophysics Data System (ADS)

Liang, Bin; Kan, Wei-wei; Zou, Xin-ye; Yin, Lei-lei; Cheng, Jian-chun

2014-08-01

We designed an acoustic transistor to manipulate sound in a manner similar to the manipulation of electric current by its electrical counterpart. The acoustic transistor is a three-terminal device with the essential ability to use a small monochromatic acoustic signal to control a much larger output signal within a broad frequency range. The output and controlling signals have the same frequency, suggesting the possibility of cascading the structure to amplify an acoustic signal. Capable of amplifying and switching sound by sound, acoustic transistors have various potential applications and may open the way to the design of conceptual devices such as acoustic logic gates.

Enhanced stability of Janus nanoparticles by covalent cross-linking of surface ligands.

PubMed

Song, Yang; Klivansky, Liana M; Liu, Yi; Chen, Shaowei

2011-12-06

A mercapto derivative of diacetylene was used as the hydrophilic ligand to prepare Janus nanoparticles by using hydrophobic hexanethiolate-protected gold (AuC6, diameter 5 nm) nanoparticles as the starting materials. The amphiphilic surface characters of the Janus nanoparticles were verified by contact angle measurements, as compared to those of the bulk-exchange counterparts where the two types of ligands were distributed rather homogeneously on the nanoparticle surface. Dynamic light scattering studies showed that the Janus nanoparticles formed stable superstructures in various solvent media that were significantly larger than those by the bulk-exchange counterparts. This was ascribed to the amphiphilic characters of the Janus nanoparticles that rendered the particles to behave analogously to conventional surfactant molecules. Notably, because of the close proximity of the diacetylene moieties on the Janus nanoparticle surface, exposure to UV irradiation led to effective covalent cross-linking between the diacetylene moieties of neighboring ligands, as manifested in UV-vis and fluorescence measurements where the emission characteristics of dimers and trimers of diacetylene were rather well-defined, in addition to the monomeric emission. In contrast, for bulk-exchange nanoparticles, no trimer emission could be identified, and the intensity of dimer emission was markedly lower (though the intensity increased with increasing diacetylene coverage on the particle surface) under the otherwise identical experimental conditions. This is largely because the diacetylene ligands were distributed on the entire particle surface, and it was difficult to find a large number of ligands situated closely so that the stringent topochemical principles for the polymerization of diacetylene derivatives could be met. Importantly, the cross-linked Janus nanoparticles were found to exhibit marked enhancement of the structural integrity, which was attributable to the impeded surface

Balancing Hole and Electron Conduction in Ambipolar Split-Gate Thin-Film Transistors.

PubMed

Yoo, Hocheon; Ghittorelli, Matteo; Lee, Dong-Kyu; Smits, Edsger C P; Gelinck, Gerwin H; Ahn, Hyungju; Lee, Han-Koo; Torricelli, Fabrizio; Kim, Jae-Joon

2017-07-10

Complementary organic electronics is a key enabling technology for the development of new applications including smart ubiquitous sensors, wearable electronics, and healthcare devices. High-performance, high-functionality and reliable complementary circuits require n- and p-type thin-film transistors with balanced characteristics. Recent advancements in ambipolar organic transistors in terms of semiconductor and device engineering demonstrate the great potential of this route but, unfortunately, the actual development of ambipolar organic complementary electronics is currently hampered by the uneven electron (n-type) and hole (p-type) conduction in ambipolar organic transistors. Here we show ambipolar organic thin-film transistors with balanced n-type and p-type operation. By manipulating air exposure and vacuum annealing conditions, we show that well-balanced electron and hole transport properties can be easily obtained. The method is used to control hole and electron conductions in split-gate transistors based on a solution-processed donor-acceptor semiconducting polymer. Complementary logic inverters with balanced charging and discharging characteristics are demonstrated. These findings may open up new opportunities for the rational design of complementary electronics based on ambipolar organic transistors.

A VLSI Neural Monitoring System With Ultra-Wideband Telemetry for Awake Behaving Subjects.

PubMed

Greenwald, E; Mollazadeh, M; Hu, C; Wei Tang; Culurciello, E; Thakor, V

2011-04-01

Long-term monitoring of neuronal activity in awake behaving subjects can provide fundamental information about brain dynamics for neuroscience and neuroengineering applications. Here, we present a miniature, lightweight, and low-power recording system for monitoring neural activity in awake behaving animals. The system integrates two custom designed very-large-scale integrated chips, a neural interface module fabricated in 0.5 μm complementary metal-oxide semiconductor technology and an ultra-wideband transmitter module fabricated in a 0.5 μm silicon-on-sapphire (SOS) technology. The system amplifies, filters, digitizes, and transmits 16 channels of neural data at a rate of 1 Mb/s. The entire system, which includes the VLSI circuits, a digital interface board, a battery, and a custom housing, is small and lightweight (24 g) and, thus, can be chronically mounted on small animals. The system consumes 4.8 mA and records continuously for up to 40 h powered by a 3.7-V, 200-mAh rechargeable lithium-ion battery. Experimental benchtop characterizations as well as in vivo multichannel neural recordings from awake behaving rats are presented here.

Transistorized PWM inverter-induction motor drive system

NASA Technical Reports Server (NTRS)

Peak, S. C.; Plunkett, A. B.

1982-01-01

This paper describes the development of a transistorized PWM inverter-induction motor traction drive system. A vehicle performance analysis was performed to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of inverter and motor specifications. The inverter was a transistorized three-phase bridge using General Electric power Darlington transistors. The description of the design and development of this inverter is the principal object of this paper. The high-speed induction motor is a design which is optimized for use with an inverter power source. The primary feedback control is a torque angle control with voltage and torque outer loop controls. A current-controlled PWM technique is used to control the motor voltage. The drive has a constant torque output with PWM operation to base motor speed and a constant horsepower output with square wave operation to maximum speed. The drive system was dynamometer tested and the results are presented.

Integrated logic circuits using single-atom transistors

PubMed Central

Mol, J. A.; Verduijn, J.; Levine, R. D.; Remacle, F.

2011-01-01

Scaling down the size of computing circuits is about to reach the limitations imposed by the discrete atomic structure of matter. Reducing the power requirements and thereby dissipation of integrated circuits is also essential. New paradigms are needed to sustain the rate of progress that society has become used to. Single-atom transistors, SATs, cascaded in a circuit are proposed as a promising route that is compatible with existing technology. We demonstrate the use of quantum degrees of freedom to perform logic operations in a complementary-metal–oxide–semiconductor device. Each SAT performs multilevel logic by electrically addressing the electronic states of a dopant atom. A single electron transistor decodes the physical multivalued output into the conventional binary output. A robust scalable circuit of two concatenated full adders is reported, where by utilizing charge and quantum degrees of freedom, the functionality of the transistor is pushed far beyond that of a simple switch. PMID:21808050

Local bipolar-transistor gain measurement for VLSI devices

NASA Astrophysics Data System (ADS)

Bonnaud, O.; Chante, J. P.

1981-08-01

A method is proposed for measuring the gain of a bipolar transistor region as small as possible. The measurement then allows the evaluation particularly of the effect of the emitter-base junction edge and the technology-process influence of VLSI-technology devices. The technique consists in the generation of charge carriers in the transistor base layer by a focused laser beam in order to bias the device in as small a region as possible. To reduce the size of the conducting area, a transversal reverse base current is forced through the base layer resistance in order to pinch in the emitter current in the illuminated region. Transistor gain is deduced from small signal measurements. A model associated with this technique is developed, and this is in agreement with the first experimental results.

High-frequency noise characterization of graphene field effect transistors on SiC substrates

NASA Astrophysics Data System (ADS)

Yu, C.; He, Z. Z.; Song, X. B.; Liu, Q. B.; Dun, S. B.; Han, T. T.; Wang, J. J.; Zhou, C. J.; Guo, J. C.; Lv, Y. J.; Cai, S. J.; Feng, Z. H.

2017-07-01

Considering its high carrier mobility and high saturation velocity, a low-noise amplifier is thought of as being the most attractive analogue application of graphene field-effect transistors. The noise performance of graphene field-effect transistors at frequencies in the K-band remains unknown. In this work, the noise parameters of a graphene transistor are measured from 10 to 26 GHz and noise models are built with the data. The extrinsic minimum noise figure for a graphene transistor reached 1.5 dB, and the intrinsic minimum noise figure was as low as 0.8 dB at a frequency of 10 GHz, which were comparable with the results from tests on Si CMOS and started to approach those for GaAs and InP transistors. Considering the short development time, the current results are a significant step forward for graphene transistors and show their application potential in high-frequency electronics.

Electrical coupling of single cardiac rat myocytes to field-effect and bipolar transistors.

PubMed

Kind, Thomas; Issing, Matthias; Arnold, Rüdiger; Müller, Bernt

2002-12-01

A novel bipolar transistor for extracellular recording the electrical activity of biological cells is presented, and the electrical behavior compared with the field-effect transistor (FET). Electrical coupling is examined between single cells separated from the heart of adults rats (cardiac myocytes) and both types of transistors. To initiate a local extracellular voltage, the cells are periodically stimulated by a patch pipette in voltage clamp and current clamp mode. The local extracellular voltage is measured by the planar integrated electronic sensors: the bipolar and the FET. The small signal transistor currents correspond to the local extracellular voltage. The two types of sensor transistors used here were developed and manufactured in the laboratory of our institute. The manufacturing process and the interfaces between myocytes and transistors are described. The recordings are interpreted by way of simulation based on the point-contact model and the single cardiac myocyte model.

Pentacene Organic Thin-Film Transistors on Flexible Paper and Glass Substrates

DTIC Science & Technology

2014-02-12

FEB 2014 2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Pentacene organic thin - film transistors on flexible...Nanotechnology 25 (2014) 094005 (7pp) doi:10.1088/0957-4484/25/9/094005 Pentacene organic thin - film transistors on flexible paper and glass substrates Adam T...organic thin - film transistors (OTFTs) were fabricated on several types of flexible substrate: commercial photo paper, ultra-smooth specialty paper and

Multiplexing of Radio-Frequency Single Electron Transistors

NASA Technical Reports Server (NTRS)

Stevenson, Thomas R.; Pellerano, F. A.; Stahle, C. M.; Aidala, K.; Schoelkopf, R. J.; Krebs, Carolyn (Technical Monitor)

2001-01-01

We present results on wavelength division multiplexing of radio-frequency single electron transistors. We use a network of resonant impedance matching circuits to direct applied rf carrier waves to different transistors depending on carrier frequency. A two-channel demonstration of this concept using discrete components successfully reconstructed input signals with small levels of cross coupling. A lithographic version of the rf circuits had measured parameters in agreement with electromagnetic modeling, with reduced cross capacitance and inductance, and should allow 20 to 50 channels to be multiplexed.

Plasmonic efficiencies of nanoparticles made of metal nitrides (TiN, ZrN) compared with gold

PubMed Central

Lalisse, Adrien; Tessier, Gilles; Plain, Jérome; Baffou, Guillaume

2016-01-01

Metal nitrides have been proposed to replace noble metals in plasmonics for some specific applications. In particular, while titanium nitride (TiN) and zirconium nitride (ZrN) possess localized plasmon resonances very similar to gold in magnitude and wavelength, they benefit from a much higher sustainability to temperature. For this reason, they are foreseen as ideal candidates for applications in nanoplasmonics that require high material temperature under operation, such as heat assisted magnetic recording (HAMR) or thermophotovoltaics. This article presents a detailed investigation of the plasmonic properties of TiN and ZrN nanoparticles in comparison with gold nanoparticles, as a function of the nanoparticle morphology. As a main result, metal nitrides are shown to be poor near-field enhancers compared to gold, no matter the nanoparticle morphology and wavelength. The best efficiencies of metal nitrides as compared to gold in term of near-field enhancement are obtained for small and spherical nanoparticles, and they do not exceed 60%. Nanoparticle enlargements or asymmetries are detrimental. These results mitigate the utility of metal nitrides for high-temperature applications such as HAMR, despite their high temperature sustainability. Nevertheless, at resonance, metal nitrides behave as efficient nanosources of heat and could be relevant for applications in thermoplasmonics, where heat generation is not detrimental but desired. PMID:27934890

Plasmonic efficiencies of nanoparticles made of metal nitrides (TiN, ZrN) compared with gold.

PubMed

Lalisse, Adrien; Tessier, Gilles; Plain, Jérome; Baffou, Guillaume

2016-12-09

Metal nitrides have been proposed to replace noble metals in plasmonics for some specific applications. In particular, while titanium nitride (TiN) and zirconium nitride (ZrN) possess localized plasmon resonances very similar to gold in magnitude and wavelength, they benefit from a much higher sustainability to temperature. For this reason, they are foreseen as ideal candidates for applications in nanoplasmonics that require high material temperature under operation, such as heat assisted magnetic recording (HAMR) or thermophotovoltaics. This article presents a detailed investigation of the plasmonic properties of TiN and ZrN nanoparticles in comparison with gold nanoparticles, as a function of the nanoparticle morphology. As a main result, metal nitrides are shown to be poor near-field enhancers compared to gold, no matter the nanoparticle morphology and wavelength. The best efficiencies of metal nitrides as compared to gold in term of near-field enhancement are obtained for small and spherical nanoparticles, and they do not exceed 60%. Nanoparticle enlargements or asymmetries are detrimental. These results mitigate the utility of metal nitrides for high-temperature applications such as HAMR, despite their high temperature sustainability. Nevertheless, at resonance, metal nitrides behave as efficient nanosources of heat and could be relevant for applications in thermoplasmonics, where heat generation is not detrimental but desired.

Going ballistic: Graphene hot electron transistors

NASA Astrophysics Data System (ADS)

Vaziri, S.; Smith, A. D.; Östling, M.; Lupina, G.; Dabrowski, J.; Lippert, G.; Mehr, W.; Driussi, F.; Venica, S.; Di Lecce, V.; Gnudi, A.; König, M.; Ruhl, G.; Belete, M.; Lemme, M. C.

2015-12-01

This paper reviews the experimental and theoretical state of the art in ballistic hot electron transistors that utilize two-dimensional base contacts made from graphene, i.e. graphene base transistors (GBTs). Early performance predictions that indicated potential for THz operation still hold true today, even with improved models that take non-idealities into account. Experimental results clearly demonstrate the basic functionality, with on/off current switching over several orders of magnitude, but further developments are required to exploit the full potential of the GBT device family. In particular, interfaces between graphene and semiconductors or dielectrics are far from perfect and thus limit experimental device integrity, reliability and performance.

Tin Dioxide Electrolyte-Gated Transistors Working in Depletion and Enhancement Modes.

PubMed

Valitova, Irina; Natile, Marta Maria; Soavi, Francesca; Santato, Clara; Cicoira, Fabio

2017-10-25

Metal oxide semiconductors are interesting for next-generation flexible and transparent electronics because of their performance and reliability. Tin dioxide (SnO 2 ) is a very promising material that has already found applications in sensing, photovoltaics, optoelectronics, and batteries. In this work, we report on electrolyte-gated, solution-processed polycrystalline SnO 2 transistors on both rigid and flexible substrates. For the transistor channel, we used both unpatterned and patterned SnO 2 films. Since decreasing the SnO 2  area in contact with the electrolyte increases the charge-carrier density, patterned transistors operate in the depletion mode, whereas unpatterned ones operate in the enhancement mode. We also fabricated flexible SnO 2 transistors that operate in the enhancement mode that can withstand moderate mechanical bending.

Bottom-Up Tri-gate Transistors and Submicrosecond Photodetectors from Guided CdS Nanowalls.

PubMed

Xu, Jinyou; Oksenberg, Eitan; Popovitz-Biro, Ronit; Rechav, Katya; Joselevich, Ernesto

2017-11-08

Tri-gate transistors offer better performance than planar transistors by exerting additional gate control over a channel from two lateral sides of semiconductor nanowalls (or "fins"). Here we report the bottom-up assembly of aligned CdS nanowalls by a simultaneous combination of horizontal catalytic vapor-liquid-solid growth and vertical facet-selective noncatalytic vapor-solid growth and their parallel integration into tri-gate transistors and photodetectors at wafer scale (cm 2 ) without postgrowth transfer or alignment steps. These tri-gate transistors act as enhancement-mode transistors with an on/off current ratio on the order of 10 8 , 4 orders of magnitude higher than the best results ever reported for planar enhancement-mode CdS transistors. The response time of the photodetector is reduced to the submicrosecond level, 1 order of magnitude shorter than the best results ever reported for photodetectors made of bottom-up semiconductor nanostructures. Guided semiconductor nanowalls open new opportunities for high-performance 3D nanodevices assembled from the bottom up.

Light programmable organic transistor memory device based on hybrid dielectric

NASA Astrophysics Data System (ADS)

Ren, Xiaochen; Chan, Paddy K. L.

2013-09-01

We have fabricated the transistor memory devices based on SiO2 and polystyrene (PS) hybrid dielectric. The trap states densities with different semiconductors have been investigated and a maximum 160V memory window between programming and erasing is realized. For DNTT based transistor, the trapped electron density is limited by the number of mobile electrons in semiconductor. The charge transport mechanism is verified by light induced Vth shift effect. Furthermore, in order to meet the low operating power requirement of portable electronic devices, we fabricated the organic memory transistor based on AlOx/self-assembly monolayer (SAM)/PS hybrid dielectric, the effective capacitance of hybrid dielectric is 210 nF cm-2 and the transistor can reach saturation state at -3V gate bias. The memory window in transfer I-V curve is around 1V under +/-5V programming and erasing bias.

Comparison studies of rheological and thermal behaviors of ionic liquids and nanoparticle ionic liquids.

PubMed

Xu, Yiting; Zheng, Qiang; Song, Yihu

2015-08-14

Novel nanoparticle ionic liquids (NILs) are prepared by grafting modified nanoparticles with long-chain ionic liquids (ILs). The NIL behaves like a liquid at ambient temperature. We studied the rheological behavior of the IL and NIL over the range of 10-55 °C and found an extraordinary difference between the IL and NIL: a small content of nanosilica (7%) moderately improves the crystallinity by 7% of the poly(ethylene glycol) (PEG) segment in the IL, and it improves the dynamic moduli significantly (by 5 times at room temperature). It retards the decay temperature (by 10 °C) of the dynamic moduli during heating as well. The thermal rheological hysteresis observed during heating-cooling temperature sweeps is ascribed to the melting-recrystallization of the PEG segments. Meanwhile, the IL and NIL express accelerated crystallization behavior in comparison with the oligomeric anion. For the first time, we find that ILs and NILs are able to form nanoparticle-containing spherulites at room temperature after long time aging.

Method for double-sided processing of thin film transistors

DOEpatents

Yuan, Hao-Chih; Wang, Guogong; Eriksson, Mark A.; Evans, Paul G.; Lagally, Max G.; Ma, Zhenqiang

2008-04-08

This invention provides methods for fabricating thin film electronic devices with both front- and backside processing capabilities. Using these methods, high temperature processing steps may be carried out during both frontside and backside processing. The methods are well-suited for fabricating back-gate and double-gate field effect transistors, double-sided bipolar transistors and 3D integrated circuits.

Flexible and low-voltage integrated circuits constructed from high-performance nanocrystal transistors.

PubMed

Kim, David K; Lai, Yuming; Diroll, Benjamin T; Murray, Christopher B; Kagan, Cherie R

2012-01-01

Colloidal semiconductor nanocrystals are emerging as a new class of solution-processable materials for low-cost, flexible, thin-film electronics. Although these colloidal inks have been shown to form single, thin-film field-effect transistors with impressive characteristics, the use of multiple high-performance nanocrystal field-effect transistors in large-area integrated circuits has not been shown. This is needed to understand and demonstrate the applicability of these discrete nanocrystal field-effect transistors for advanced electronic technologies. Here we report solution-deposited nanocrystal integrated circuits, showing nanocrystal integrated circuit inverters, amplifiers and ring oscillators, constructed from high-performance, low-voltage, low-hysteresis CdSe nanocrystal field-effect transistors with electron mobilities of up to 22 cm(2) V(-1) s(-1), current modulation >10(6) and subthreshold swing of 0.28 V dec(-1). We fabricated the nanocrystal field-effect transistors and nanocrystal integrated circuits from colloidal inks on flexible plastic substrates and scaled the devices to operate at low voltages. We demonstrate that colloidal nanocrystal field-effect transistors can be used as building blocks to construct complex integrated circuits, promising a viable material for low-cost, flexible, large-area electronics.

Silicon switching transistor with high power and low saturation voltage

NASA Technical Reports Server (NTRS)

Stonebraker, E.; Stoneburner, D.; Ferree, H.

1973-01-01

Assembly of two individually encapsulated silicon-chip transistors produces silicon power-transistor that has low electrical resistance and low thermal impedance. Electrical resistance and thermal impedance are low because of short lead lengths, and external contact surfaces are plated to reduce resistance at interfaces.

All diamond self-aligned thin film transistor

DOEpatents

Gerbi, Jennifer [Champaign, IL

2008-07-01

A substantially all diamond transistor with an electrically insulating substrate, an electrically conductive diamond layer on the substrate, and a source and a drain contact on the electrically conductive diamond layer. An electrically insulating diamond layer is in contact with the electrically conductive diamond layer, and a gate contact is on the electrically insulating diamond layer. The diamond layers may be homoepitaxial, polycrystalline, nanocrystalline or ultrananocrystalline in various combinations.A method of making a substantially all diamond self-aligned gate transistor is disclosed in which seeding and patterning can be avoided or minimized, if desired.

VHDL simulation with access to transistor models

NASA Technical Reports Server (NTRS)

Gibson, J.

1991-01-01

Hardware description languages such as VHDL have evolved to aid in the design of systems with large numbers of elements and a wide range of electronic and logical abstractions. For high performance circuits, behavioral models may not be able to efficiently include enough detail to give designers confidence in a simulation's accuracy. One option is to provide a link between the VHDL environment and a transistor level simulation environment. The coupling of the Vantage Analysis Systems VHDL simulator and the NOVA simulator provides the combination of VHDL modeling and transistor modeling.

Electron transporting water-gated thin film transistors

NASA Astrophysics Data System (ADS)

Al Naim, Abdullah; Grell, Martin

2012-10-01

We demonstrate an electron-transporting water-gated thin film transistor, using thermally converted precursor-route zinc-oxide (ZnO) intrinsic semiconductors with hexamethyldisilazene (HMDS) hydrophobic surface modification. Water gated HMDS-ZnO thin film transistors (TFT) display low threshold and high electron mobility. ZnO films constitute an attractive alternative to organic semiconductors for TFT transducers in sensor applications for waterborne analytes. Despite the use of an electrolyte as gate medium, the gate geometry (shape of gate electrode and distance between gate electrode and TFT channel) is relevant for optimum performance of water-gated TFTs.

Static Characteristics of the Ferroelectric Transistor Inverter

NASA Technical Reports Server (NTRS)

Mitchell, Cody; Laws, crystal; MacLeond, Todd C.; Ho, Fat D.

2010-01-01

The inverter is one of the most fundamental building blocks of digital logic, and it can be used as the foundation for understanding more complex logic gates and circuits. This paper presents the characteristics of an inverter circuit using a ferroelectric field-effect transistor. The voltage transfer characteristics are analyzed with respect to varying parameters such as supply voltage, input voltage, and load resistance. The effects of the ferroelectric layer between the gate and semiconductor are examined, and comparisons are made between the inverters using ferroelectric transistors and those using traditional MOSFETs.

Fabrication of eco-friendly PNP transistor using RF magnetron sputtering

NASA Astrophysics Data System (ADS)

Kumar, B. Santhosh; Harinee, N.; Purvaja, K.; Shanker, N. Praveen; Manikandan, M.; Aparnadevi, N.; Mukilraj, T.; Venkateswaran, C.

2018-05-01

An effort has been made to fabricate a thin film transistor using eco-friendly oxide semiconductor materials. Oxide semiconductor materials are cost - effective, thermally and chemically stable with high electron/hole mobility. Copper (II) oxide is a p-type semiconductor and zinc oxide is an n-type semiconductor. A pnp thin film transistor was fabricated using RF magnetron sputtering. The films deposited have been subjected to structural characterization using AFM. I-V characterization of the fabricated device, Ag/CuO/ZnO/CuO/Ag, confirms transistor behaviour. The mechanism of electron/hole transport of the device is discussed below.

Quantum Optical Transistor and Other Devices Based on Nanostructures

NASA Astrophysics Data System (ADS)

Li, Jin-Jin; Zhu, Ka-Di

Laser and strong coupling can coexist in a single quantum dot (QD) coupled to nanostructures. This provides an important clue toward the realization of quantum optical devices, such as quantum optical transistor, slow light device, fast light device, or light storage device. In contrast to conventional electronic transistor, a quantum optical transistor uses photons as signal carriers rather than electrons, which has a faster and more powerful transfer efficiency. Under the radiation of a strong pump laser, a signal laser can be amplified or attenuated via passing through a single quantum dot coupled to a photonic crystal (PC) nanocavity system. Such a switching and amplifying behavior can really implement the quantum optical transistor. By simply turning on or off the input pump laser, the amplified or attenuated signal laser can be obtained immediately. Based on this transistor, we further propose a method to measure the vacuum Rabi splitting of exciton in all-optical domain. Besides, we study the light propagation in a coupled QD and nanomechanical resonator (NR) system. We demonstrate that it is possible to achieve the slow light, fast light, and quantum memory for light on demand, which is based on the mechanically induced coherent population oscillation (MICPO) and exciton polaritons. These QD devices offer a route toward the use of all-optical technique to investigate the coupled QD systems and will make contributions to quantum internets and quantum computers.

Study on the Hydrogenated ZnO-Based Thin Film Transistors. Part 1

DTIC Science & Technology

2011-04-30

IGZO film on the performance of thin film transistors 5 Chapter 2. Hydrogenation of a- IGZO channel layer in the thin film transistors 12...effect of substrate temperature during the deposition of a- IGZO film on the performance of thin film transistors Introduction The effect of substrate...temperature during depositing IGZO channel layer on the performance of amorphous indium-gallium-zinc oxide (a- IGZO

Feasibility Study of Extended-Gate-Type Silicon Nanowire Field-Effect Transistors for Neural Recording

PubMed Central

Kang, Hongki; Kim, Jee-Yeon; Choi, Yang-Kyu; Nam, Yoonkey

2017-01-01

In this research, a high performance silicon nanowire field-effect transistor (transconductance as high as 34 µS and sensitivity as 84 nS/mV) is extensively studied and directly compared with planar passive microelectrode arrays for neural recording application. Electrical and electrochemical characteristics are carefully characterized in a very well-controlled manner. We especially focused on the signal amplification capability and intrinsic noise of the transistors. A neural recording system using both silicon nanowire field-effect transistor-based active-type microelectrode array and platinum black microelectrode-based passive-type microelectrode array are implemented and compared. An artificial neural spike signal is supplied as input to both arrays through a buffer solution and recorded simultaneously. Recorded signal intensity by the silicon nanowire transistor was precisely determined by an electrical characteristic of the transistor, transconductance. Signal-to-noise ratio was found to be strongly dependent upon the intrinsic 1/f noise of the silicon nanowire transistor. We found how signal strength is determined and how intrinsic noise of the transistor determines signal-to-noise ratio of the recorded neural signals. This study provides in-depth understanding of the overall neural recording mechanism using silicon nanowire transistors and solid design guideline for further improvement and development. PMID:28350370

Feasibility Study of Extended-Gate-Type Silicon Nanowire Field-Effect Transistors for Neural Recording.

PubMed

Kang, Hongki; Kim, Jee-Yeon; Choi, Yang-Kyu; Nam, Yoonkey

2017-03-28

In this research, a high performance silicon nanowire field-effect transistor (transconductance as high as 34 µS and sensitivity as 84 nS/mV) is extensively studied and directly compared with planar passive microelectrode arrays for neural recording application. Electrical and electrochemical characteristics are carefully characterized in a very well-controlled manner. We especially focused on the signal amplification capability and intrinsic noise of the transistors. A neural recording system using both silicon nanowire field-effect transistor-based active-type microelectrode array and platinum black microelectrode-based passive-type microelectrode array are implemented and compared. An artificial neural spike signal is supplied as input to both arrays through a buffer solution and recorded simultaneously. Recorded signal intensity by the silicon nanowire transistor was precisely determined by an electrical characteristic of the transistor, transconductance. Signal-to-noise ratio was found to be strongly dependent upon the intrinsic 1/f noise of the silicon nanowire transistor. We found how signal strength is determined and how intrinsic noise of the transistor determines signal-to-noise ratio of the recorded neural signals. This study provides in-depth understanding of the overall neural recording mechanism using silicon nanowire transistors and solid design guideline for further improvement and development.

Capillary electrophoresis with gold nanoparticles enhanced electrochemiluminescence for the detection of roxithromycin.

PubMed

Wang, Jingwu; Yang, Zhiming; Wang, Xiaoxia; Yang, Nianjun

2008-06-30

Tris(2,2'-bipyridyl) ruthenium(II) (Ru(bpy)(3)(2+))-roxithromycin based electrochemiluminescence (ECL) was enhanced greatly by gold nanoparticles 10 nm in diameter. Capillary electrophoresis (CE) was coupled with the resultant ECL system as a detector for roxithromycin. This ECL emission is explained by the coreactant mechanism where roxithromycin behaves as a coreactant to generate strong reducing species and gold nanoparticles act as "floating nanoelectrodes". The reaction of Ru(bpy)(3)(3+) with the generated strong reducing species on the Pt working electrode as well as on "floating nanoelectrodes" releases Ru(bpy)(3)(2+*), resulting in enhancement of ECL emission. The selectivity of this detection system towards roxithromycin was examined by CE. Under the optimized conditions, the intensity of ECL emission varies linearly with the concentration of roxithromycin from 24 nM to 0.24 mM. The detection limit is 8.4 nM, while without adding gold nanoparticles it is only 84 nM. The detection of roxithromycin in pharmaceutical and urine samples was also performed by the proposed CE-ECL method.

Printing Semiconductor-Insulator Polymer Bilayers for High-Performance Coplanar Field-Effect Transistors.

PubMed

Bu, Laju; Hu, Mengxing; Lu, Wanlong; Wang, Ziyu; Lu, Guanghao

2018-01-01

Source-semiconductor-drain coplanar transistors with an organic semiconductor layer located within the same plane of source/drain electrodes are attractive for next-generation electronics, because they could be used to reduce material consumption, minimize parasitic leakage current, avoid cross-talk among different devices, and simplify the fabrication process of circuits. Here, a one-step, drop-casting-like printing method to realize a coplanar transistor using a model semiconductor/insulator [poly(3-hexylthiophene) (P3HT)/polystyrene (PS)] blend is developed. By manipulating the solution dewetting dynamics on the metal electrode and SiO 2 dielectric, the solution within the channel region is selectively confined, and thus make the top surface of source/drain electrodes completely free of polymers. Subsequently, during solvent evaporation, vertical phase separation between P3HT and PS leads to a semiconductor-insulator bilayer structure, contributing to an improved transistor performance. Moreover, this coplanar transistor with semiconductor-insulator bilayer structure is an ideal system for injecting charges into the insulator via gate-stress, and the thus-formed PS electret layer acts as a "nonuniform floating gate" to tune the threshold voltage and effective mobility of the transistors. Effective field-effect mobility higher than 1 cm 2 V -1 s -1 with an on/off ratio > 10 7 is realized, and the performances are comparable to those of commercial amorphous silicon transistors. This coplanar transistor simplifies the fabrication process of corresponding circuits. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Theoretical and experimental characterization of the DUal-BAse transistor (DUBAT)

NASA Astrophysics Data System (ADS)

Wu, Chung-Yu; Wu, Ching-Yuan

1980-11-01

A new A-type integrated voltage controlled differential negative resistance device using an extra effective base region to form a lateral pnp (npn) bipolar transistor beside the original base region of a vertical npn (pnp) bipolar junction transistor, and so called the DUal BAse Transistor (DUBAT), is studied both experimentally and theoretically, The DUBAT has three terminals and is fully comparible with the existing bipolar integrated circuits technologies. Based upon the equivalent circuit of the DUBAT, a simple first-order analytical theory is developed, and important device parameters, such as: the I-V characteristic, the differential negative resistance, and the peak and valley points, are also characterized. One of the proposed integrated structures of the DUBAT, which is similar in structure to I 2L but with similar high density and a normally operated vertical npn transistor, has been successfully fabricated and studied. Comparisons between the experimental data and theoretical analyses are made, and show in satisfactory agreements.

High-frequency self-aligned graphene transistors with transferred gate stacks

PubMed Central

Cheng, Rui; Bai, Jingwei; Liao, Lei; Zhou, Hailong; Chen, Yu; Liu, Lixin; Lin, Yung-Chen; Jiang, Shan; Huang, Yu; Duan, Xiangfeng

2012-01-01

Graphene has attracted enormous attention for radio-frequency transistor applications because of its exceptional high carrier mobility, high carrier saturation velocity, and large critical current density. Herein we report a new approach for the scalable fabrication of high-performance graphene transistors with transferred gate stacks. Specifically, arrays of gate stacks are first patterned on a sacrificial substrate, and then transferred onto arbitrary substrates with graphene on top. A self-aligned process, enabled by the unique structure of the transferred gate stacks, is then used to position precisely the source and drain electrodes with minimized access resistance or parasitic capacitance. This process has therefore enabled scalable fabrication of self-aligned graphene transistors with unprecedented performance including a record-high cutoff frequency up to 427 GHz. Our study defines a unique pathway to large-scale fabrication of high-performance graphene transistors, and holds significant potential for future application of graphene-based devices in ultra–high-frequency circuits. PMID:22753503

High-frequency self-aligned graphene transistors with transferred gate stacks.

PubMed

Cheng, Rui; Bai, Jingwei; Liao, Lei; Zhou, Hailong; Chen, Yu; Liu, Lixin; Lin, Yung-Chen; Jiang, Shan; Huang, Yu; Duan, Xiangfeng

2012-07-17

Graphene has attracted enormous attention for radio-frequency transistor applications because of its exceptional high carrier mobility, high carrier saturation velocity, and large critical current density. Herein we report a new approach for the scalable fabrication of high-performance graphene transistors with transferred gate stacks. Specifically, arrays of gate stacks are first patterned on a sacrificial substrate, and then transferred onto arbitrary substrates with graphene on top. A self-aligned process, enabled by the unique structure of the transferred gate stacks, is then used to position precisely the source and drain electrodes with minimized access resistance or parasitic capacitance. This process has therefore enabled scalable fabrication of self-aligned graphene transistors with unprecedented performance including a record-high cutoff frequency up to 427 GHz. Our study defines a unique pathway to large-scale fabrication of high-performance graphene transistors, and holds significant potential for future application of graphene-based devices in ultra-high-frequency circuits.

A Vertical Organic Transistor Architecture for Fast Nonvolatile Memory.

PubMed

She, Xiao-Jian; Gustafsson, David; Sirringhaus, Henning

2017-02-01

A new device architecture for fast organic transistor memory is developed, based on a vertical organic transistor configuration incorporating high-performance ambipolar conjugated polymers and unipolar small molecules as the transport layers, to achieve reliable and fast programming and erasing of the threshold voltage shift in less than 200 ns. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Small-Angle Neutron Scattering Study of Interplay of Attractive and Repulsive Interactions in Nanoparticle-Polymer System.

PubMed

Kumar, Sugam; Aswal, Vinod K; Kohlbrecher, Joachim

2016-02-16

The phase behavior of nanoparticle (silica)-polymer (polyethylene glycol) system without and with an electrolyte (NaCl) has been studied. It is observed that nanoparticle-polymer system behaves very differently in the presence of electrolyte. In the absence of electrolyte, the nanoparticle-polymer system remains in one-phase even at very high polymer concentrations. On the other hand, a re-entrant phase behavior is found in the presence of electrolyte, where one-phase (individual) system undergoes two-phase (nanoparticle aggregation) and then back to one-phase with increasing polymer concentration. The regime of two-phase system has been tuned by varying the electrolyte concentration. The polymer concentration range over which the two-phase system exists is significantly enhanced with the increase in the electrolyte concentration. These systems have been characterized by small-angle neutron scattering (SANS) experiments of contrast-marching the polymer to the solvent. The data are modeled using a two-Yukawa potential accounting for both attractive and repulsive parts of the interaction between nanoparticles. The phase behavior of nanoparticle-polymer system is explained by interplay of attractive (polymer-induced attractive depletion between nanoparticles) and repulsive (nanoparticle-nanoparticle electrostatic repulsion and polymer-polymer repulsion) interactions present in the system. In the absence of electrolyte, the strong electrostatic repulsion between nanoparticles dominates over the polymer-induced depletion attraction and the nanoparticle system remains in one-phase. With addition of electrolyte, depletion attraction overcomes electrostatic repulsion at some polymer concentration, resulting into nanoparticle aggregation and two-phase system. Further addition of polymer increases the polymer-polymer repulsion which eventually reduces the strength of depletion and hence re-entrant phase behavior. The effects of varying electrolyte concentration on the phase

Organic Electrochemical Transistors for the Detection of Cell Surface Glycans.

PubMed

Chen, Lizhen; Fu, Ying; Wang, Naixiang; Yang, Anneng; Li, Yuanzhe; Wu, Jie; Ju, Huangxian; Yan, Feng

2018-05-23

Cell surface glycans play critical roles in diverse biological processes, such as cell-cell communication, immunity, infection, development, and differentiation. Their expressions are closely related to cancer growth and metastasis. This work demonstrates an organic electrochemical transistor (OECT)-based biosensor for the detection of glycan expression on living cancer cells. Herein, mannose on human breast cancer cells (MCF-7) as the target glycan model, poly dimethyl diallyl ammonium chloride-multiwall carbon nanotubes (PDDA-MWCNTs) as the loading interface, concanavalin A (Con A) with active mannose binding sites, aptamer and horseradish peroxidase co-immobilized gold nanoparticles (HRP-aptamer-Au NPs) as specific nanoprobes are used to fabricate the OECT biosensor. In this strategy, PDDA-MWCNT interfaces can enhance the loading of Con A, and the target cells can be captured through Con A via active mannose binding sites. Thus, the expression of cell surface can be reflected by the amount of cells captured on the gate. Specific nanoprobes are introduced to the captured cells to produce an OECT signal because of the reduction of hydrogen peroxide catalyzed by HRP conjugated on Au nanoparticles, while the aptamer on nanoprobes can selectively recognize the MCF-7 cells. It is reasonable that more target cells are captured on the gate electrode, more HRP-nanoprobes are loaded thus a larger signal response. The device shows an obvious response to MCF-7 cells down to 10 cells/μL and can be used to selectively monitor the change of mannose expression on cell surfaces upon a treatment with the N-glycan inhibitor. The OECT-based biosensor is promising for the analysis of glycan expressions on the surfaces of different types of cells.

High Stability Pentacene Transistors Using Polymeric Dielectric Surface Modifier.

PubMed

Wang, Xiaohong; Lin, Guangqing; Li, Peng; Lv, Guoqiang; Qiu, Longzhen; Ding, Yunsheng

2015-08-01

1,6-bis(trichlorosilyl)hexane (C6Cl), polystyrene (PS), and cross-linked polystyrene (CPS) were investigated as gate dielectric modified layers for high performance organic transistors. The influence of the surface energy, roughness and morphology on the charge transport of the organic thin-film transistors (OTFTs) was investigated. The surface energy and roughness both affect the grain size of the pentacene films which will control the charge carrier mobility of the devices. Pentacene thin-film transistors fabricated on the CPS modified dielectric layers exhibited charge carrier mobility as high as 1.11 cm2 V-1 s-1. The bias stress stability for the CPS devices shows that the drain current only decays 1% after 1530 s and the mobility never decreases until 13530 s.

P-channel transparent thin-film transistor using physical-vapor-deposited NiO layer

NASA Astrophysics Data System (ADS)

Lin, Chiung-Wei; Chung, Wei-Chieh; Zhang, Zhao-De; Hsu, Ming-Chih

2018-01-01

The effect of oxygen (O) content on the electrical properties of physical-vapor-deposited nickel oxide (PVD-NiO) was studied. When the NiO target was sputtered, introducing O2 can lead to the formation of Ni3+ ions in the deposited film. These Ni3+ ions can act as acceptors. However, there were too many Ni3+ ions that were obtained following the introduction of O atoms. It resulted in intensive p-type conduction and made the O2-introduced PVD-NiO behave as a conductor. Thus, it was possible to reduce the O content of PVD-NiO to obtain a p-type semiconductor. In this study, a transparent PVD-NiO film with a carrier concentration of 1.62 × 1017 cm-3 and a resistivity of 3.74 Ω cm was sputter-deposited within pure argon plasma. The thin-film transistor (TFT) employing this proposed PVD-NiO can result in good current switching, and even operated at very low drain-source voltage. The ON/OFF current ratio, field-effect carrier mobility, and threshold voltage of the proposed NiO TFT were 3.61 × 104, 1.09 cm2 V-1 s-1 and -3.31 V, respectively.

Organic field-effect transistors using single crystals.

PubMed

Hasegawa, Tatsuo; Takeya, Jun

2009-04-01

Organic field-effect transistors using small-molecule organic single crystals are developed to investigate fundamental aspects of organic thin-film transistors that have been widely studied for possible future markets for 'plastic electronics'. In reviewing the physics and chemistry of single-crystal organic field-effect transistors (SC-OFETs), the nature of intrinsic charge dynamics is elucidated for the carriers induced at the single crystal surfaces of molecular semiconductors. Materials for SC-OFETs are first reviewed with descriptions of the fabrication methods and the field-effect characteristics. In particular, a benchmark carrier mobility of 20-40 cm 2 Vs -1 , achieved with thin platelets of rubrene single crystals, demonstrates the significance of the SC-OFETs and clarifies material limitations for organic devices. In the latter part of this review, we discuss the physics of microscopic charge transport by using SC-OFETs at metal/semiconductor contacts and along semiconductor/insulator interfaces. Most importantly, Hall effect and electron spin resonance (ESR) measurements reveal that interface charge transport in molecular semiconductors is properly described in terms of band transport and localization by charge traps.

Coulomb-coupled quantum-dot thermal transistors

NASA Astrophysics Data System (ADS)

Zhang, Yanchao; Yang, Zhimin; Zhang, Xin; Lin, Bihong; Lin, Guoxing; Chen, Jincan

2018-04-01

A quantum-dot thermal transistor consisting of three Coulomb-coupled quantum dots coupled to the respective electronic reservoirs by tunnel contacts is established. The heat flows through the collector and emitter can be controlled by the temperature of the base. It is found that a small change in the base heat flow can induce a large heat flow change in the collector and emitter. The huge amplification factor can be obtained by optimizing the Coulomb interaction between the collector and the emitter or by decreasing the tunneling rate at the base. The proposed quantum-dot thermal transistor may open up potential applications in low-temperature solid-state thermal circuits at the nanoscale.

BehavePlus fire modeling system, version 4.0: User's Guide

Treesearch

Patricia L. Andrews; Collin D. Bevins; Robert C. Seli

2005-01-01

The BehavePlus fire modeling system is a program for personal computers that is a collection of mathematical models that describe fire and the fire environment. It is a flexible system that produces tables, graphs, and simple diagrams. It can be used for a multitude of fire management applications including projecting the behavior of an ongoing fire, planning...

Quantum structures for recombination control in the light-emitting transistor

NASA Astrophysics Data System (ADS)

Chen, Kanuo; Hsiao, Fu-Chen; Joy, Brittany; Dallesasse, John M.

2017-02-01

Recombination of carriers in the direct-bandgap base of a transistor-injected quantum cascade laser (TI-QCL) is shown to be controllable through the field applied across the quantum cascade region located in the transistor's base-collector junction. The influence of the electric field on the quantum states in the cascade region's superlattice allows free flow of electrons out of the transistor base only for field values near the design field that provides optimal QCL gain. Quantum modulation of base recombination in the light-emitting transistor is therefore observed. In a GaAs-based light-emitting transistor, a periodic superlattice is grown between the p-type base and the n-type collector. Under different base-collector biasing conditions the distribution of quantum states, and as a consequence transition probabilities through the wells and barriers forming the cascade region, leads to strong field-dependent mobility for electrons in transit through the base-collector junction. The radiative base recombination, which is influenced by minority carrier transition lifetime, can be modulated through the quantum states alignment in the superlattice. A GaAs-based transistor-injected quantum cascade laser with AlGaAs/GaAs superlattice is designed and fabricated. Radiative base recombination is measured under both common-emitter and common-base configuration. In both configurations the optical output from the base is proportional to the emitter injection. When the quantum states in the superlattice are aligned the optical output in the base is reduced as electrons encounter less impedance entering the collector; when the quantum states are misaligned electrons have longer lifetime in the base and the radiative base recombination process is enhanced.

'Soft' amplifier circuits based on field-effect ionic transistors.

PubMed

Boon, Niels; Olvera de la Cruz, Monica

2015-06-28

Soft materials can be used as the building blocks for electronic devices with extraordinary properties. We introduce a theoretical model for a field-effect transistor in which ions are the gated species instead of electrons. Our model incorporates readily-available soft materials, such as conductive porous membranes and polymer-electrolytes to represent a device that regulates ion currents and can be integrated as a component in larger circuits. By means of Nernst-Planck numerical simulations as well as an analytical description of the steady-state current we find that the responses of the system to various input voltages can be categorized into ohmic, sub-threshold, and active modes. This is fully analogous to what is known for the electronic field-effect transistor (FET). Pivotal FET properties such as the threshold voltage and the transconductance crucially depend on the half-cell redox potentials of the source and drain electrodes as well as on the polyelectrolyte charge density and the gate material work function. We confirm the analogy with the electronic FETs through numerical simulations of elementary amplifier circuits in which we successfully substitute the electronic transistor by an ionic transistor.

Flexible black phosphorus ambipolar transistors, circuits and AM demodulator.

PubMed

Zhu, Weinan; Yogeesh, Maruthi N; Yang, Shixuan; Aldave, Sandra H; Kim, Joon-Seok; Sonde, Sushant; Tao, Li; Lu, Nanshu; Akinwande, Deji

2015-03-11

High-mobility two-dimensional (2D) semiconductors are desirable for high-performance mechanically flexible nanoelectronics. In this work, we report the first flexible black phosphorus (BP) field-effect transistors (FETs) with electron and hole mobilities superior to what has been previously achieved with other more studied flexible layered semiconducting transistors such as MoS2 and WSe2. Encapsulated bottom-gated BP ambipolar FETs on flexible polyimide afforded maximum carrier mobility of about 310 cm(2)/V·s with field-effect current modulation exceeding 3 orders of magnitude. The device ambipolar functionality and high-mobility were employed to realize essential circuits of electronic systems for flexible technology including ambipolar digital inverter, frequency doubler, and analog amplifiers featuring voltage gain higher than other reported layered semiconductor flexible amplifiers. In addition, we demonstrate the first flexible BP amplitude-modulated (AM) demodulator, an active stage useful for radio receivers, based on a single ambipolar BP transistor, which results in audible signals when connected to a loudspeaker or earphone. Moreover, the BP transistors feature mechanical robustness up to 2% uniaxial tensile strain and up to 5000 bending cycles.

Method for fabricating transistors using crystalline silicon devices on glass

DOEpatents

McCarthy, Anthony M.

1997-01-01

A method for fabricating transistors using single-crystal silicon devices on glass. This method overcomes the potential damage that may be caused to the device during high voltage bonding and employs a metal layer which may be incorporated as part of the transistor. This is accomplished such that when the bonding of the silicon wafer or substrate to the glass substrate is performed, the voltage and current pass through areas where transistors will not be fabricated. After removal of the silicon substrate, further metal may be deposited to form electrical contact or add functionality to the devices. By this method both single and gate-all-around devices may be formed.

Pushing the Performance Limit of Sub-100 nm Molybdenum Disulfide Transistors.

PubMed

Liu, Yuan; Guo, Jian; Wu, Yecun; Zhu, Enbo; Weiss, Nathan O; He, Qiyuan; Wu, Hao; Cheng, Hung-Chieh; Xu, Yang; Shakir, Imran; Huang, Yu; Duan, Xiangfeng

2016-10-12

Two-dimensional semiconductors (2DSCs) such as molybdenum disulfide (MoS 2 ) have attracted intense interest as an alternative electronic material in the postsilicon era. However, the ON-current density achieved in 2DSC transistors to date is considerably lower than that of silicon devices, and it remains an open question whether 2DSC transistors can offer competitive performance. A high current device requires simultaneous minimization of the contact resistance and channel length, which is a nontrivial challenge for atomically thin 2DSCs, since the typical low contact resistance approaches for 2DSCs either degrade the electronic properties of the channel or are incompatible with the fabrication process for short channel devices. Here, we report a new approach toward high-performance MoS 2 transistors by using a physically assembled nanowire as a lift-off mask to create ultrashort channel devices with pristine MoS 2 channel and self-aligned low resistance metal/graphene hybrid contact. With the optimized contact in short channel devices, we demonstrate sub-100 nm MoS 2 transistor delivering a record high ON-current of 0.83 mA/μm at 300 K and 1.48 mA/μm at 20 K, which compares well with that of silicon devices. Our study, for the first time, demonstrates that the 2DSC transistors can offer comparable performance to the 2017 target for silicon transistors in International Technology Roadmap for Semiconductors (ITRS), marking an important milestone in 2DSC electronics.

Measurement and Analysis of a Ferroelectric Field-Effect Transistor NAND Gate

NASA Technical Reports Server (NTRS)

Phillips, Thomas A.; MacLeond, Todd C.; Sayyah, Rana; Ho, Fat Duen

2009-01-01

Previous research investigated expanding the use of Ferroelectric Field-Effect Transistors (FFET) to other electronic devices beyond memory circuits. Ferroelectric based transistors possess unique characteris tics that give them interesting and useful properties in digital logic circuits. The NAND gate was chosen for investigation as it is one of the fundamental building blocks of digital electronic circuits. In t his paper, NAND gate circuits were constructed utilizing individual F FETs. N-channel FFETs with positive polarization were used for the standard CMOS NAND gate n-channel transistors and n-channel FFETs with n egative polarization were used for the standard CMOS NAND gate p-chan nel transistors. The voltage transfer curves were obtained for the NA ND gate. Comparisons were made between the actual device data and the previous modeled data. These results are compared to standard MOS logic circuits. The circuits analyzed are not intended to be fully opera tional circuits that would interface with existing logic circuits, bu t as a research tool to look into the possibility of using ferroelectric transistors in future logic circuits. Possible applications for th ese devices are presented, and their potential benefits and drawbacks are discussed.

Metal-Ferroelectric-Semiconductor Field-Effect Transistor NAND Gate Switching Time Analysis

NASA Technical Reports Server (NTRS)

Phillips, Thomas A.; Macleod, Todd C.; Ho, Fat D.

2006-01-01

Previous research investigated the modeling of a N Wga te constructed of Metal-Ferroelectric- Semiconductor Field-Effect Transistors (MFSFETs) to obtain voltage transfer curves. The NAND gate was modeled using n-channel MFSFETs with positive polarization for the standard CMOS n-channel transistors and n-channel MFSFETs with negative polarization for the standard CMOS p-channel transistors. This paper investigates the MFSFET NAND gate switching time propagation delay, which is one of the other important parameters required to characterize the performance of a logic gate. Initially, the switching time of an inverter circuit was analyzed. The low-to-high and high-to-low propagation time delays were calculated. During the low-to-high transition, the negatively polarized transistor pulls up the output voltage, and during the high-to-low transition, the positively polarized transistor pulls down the output voltage. The MFSFETs were simulated by using a previously developed model which utilized a partitioned ferroelectric layer. Then the switching time of a 2-input NAND gate was analyzed similarly to the inverter gate. Extension of this technique to more complicated logic gates using MFSFETs will be studied.

Magnetic properties of ferritin and akaganeite nanoparticles in aqueous suspension

NASA Astrophysics Data System (ADS)

Koralewski, Marceli; Pochylski, Mikołaj; Gierszewski, Jacek

2013-09-01

We have studied the magnetically induced optical birefringence Δ n of horse spleen ferritin (HSF) and aqueous suspensions of several different-sized iron oxyhydroxide nanoparticles coated with different polysaccharides mimicking ferritin. The structure and dimensions of the akaganeite mineral core were characterized by XRD and TEM, respectively. The stability of the suspensions in the measurement temperature range from 278 to 358 K was confirmed by UV-Vis absorption spectroscopy. The values of optical polarizability anisotropy Δ α, magnetic susceptibility anisotropy Δ χ, and permanent magnetic dipole moment μ m of the akaganeite nanoparticles have been estimated on the basis of the temperature dependence of the Cotton-Mouton (C-M) constant. The magnetic birefringence of Fe-sucrose has been described tentatively by different types of Langevin function allowing another estimation of Δ χ and μ m. The obtained permanent magnetic dipole moment μ m of the studied akaganeite nanoparticles proves small and comparable to that of HSF. The value of μ m is found to increase with decreasing nanoparticle diameter. Observed in a range spanning more than five orders of magnitude, the linear relation between the C-M constant and the iron concentration provides a basis for possible analytical application of the C-M effect in biomedicine. The established relation between the C-M constant and the nanoparticle diameter confirms that the dominant contribution to the measured magnetic birefringence comes from the magnetic susceptibility anisotropy Δ χ. A comparison of the C-M constants of the studied akaganeite nanoparticles with the data obtained for HSF provides evidence that the ferritin core behaves as a non-Euclidian solid.

Combining protein-shelled platinum nanoparticles with graphene to build a bionanohybrid capacitor.

PubMed

San, Boi Hoa; Kim, Jang Ah; Kulkarni, Atul; Moh, Sang Hyun; Dugasani, Sreekantha Reddy; Subramani, Vinod Kumar; Thorat, Nanasaheb D; Lee, Hyun Ho; Park, Sung Ha; Kim, Taesung; Kim, Kyeong Kyu

2014-12-23

The electronic properties of biomolecules and their hybrids with inorganic materials can be utilized for the fabrication of nanoelectronic devices. Here, we report the charge transport behavior of protein-shelled inorganic nanoparticles combined with graphene and demonstrate their possible application as a bionanohybrid capacitor. The conductivity of PepA, a bacterial aminopeptidase used as a protein shell (PS), and the platinum nanoparticles (PtNPs) encapsulated by PepA was measured using a field effect transistor (FET) and a graphene-based FET (GFET). Furthermore, we confirmed that the electronic properties of PepA-PtNPs were controlled by varying the size of the PtNPs. The use of two poly(methyl methacrylate) (PMMA)-coated graphene layers separated by PepA-PtNPs enabled us to build a bionanohybrid capacitor with tunable properties. The combination of bioinorganic nanohybrids with graphene is regarded as the cornerstone for developing flexible and biocompatible bionanoelectronic devices that can be integrated into bioelectric circuits for biomedical purposes.

Analysis of long-channel nanotube field-effect-transistors (NT FETs)

NASA Technical Reports Server (NTRS)

Toshishige, Yamada; Kwak, Dochan (Technical Monitor)

2001-01-01

This viewgraph presentation provides an analysis of long-channel nanotube (NT) field effect transistors (FET) from NASA's Ames Research Center. The structure of such a transistor including the electrode contact, 1D junction, and the planar junction is outlined. Also mentioned are various characteristics of a nanotube tip-equipped scanning tunnel microscope (STM).

Noise characteristics of single-walled carbon nanotube network transistors.

PubMed

Kim, Un Jeong; Kim, Kang Hyun; Kim, Kyu Tae; Min, Yo-Sep; Park, Wanjun

2008-07-16

The noise characteristics of randomly networked single-walled carbon nanotubes grown directly by plasma enhanced chemical vapor deposition (PECVD) are studied with field effect transistors (FETs). Due to the geometrical complexity of nanotube networks in the channel area and the large number of tube-tube/tube-metal junctions, the inverse frequency, 1/f, dependence of the noise shows a similar level to that of a single single-walled carbon nanotube transistor. Detailed analysis is performed with the parameters of number of mobile carriers and mobility in the different environment. This shows that the change in the number of mobile carriers resulting in the mobility change due to adsorption and desorption of gas molecules (mostly oxygen molecules) to the tube surface is a key factor in the 1/f noise level for carbon nanotube network transistors.

Cryogenic preamplification of a single-electron-transistor using a silicon-germanium heterojunction-bipolar-transistor

NASA Astrophysics Data System (ADS)

Curry, M. J.; England, T. D.; Bishop, N. C.; Ten-Eyck, G.; Wendt, J. R.; Pluym, T.; Lilly, M. P.; Carr, S. M.; Carroll, M. S.

2015-05-01

We examine a silicon-germanium heterojunction bipolar transistor (HBT) for cryogenic pre-amplification of a single electron transistor (SET). The SET current modulates the base current of the HBT directly. The HBT-SET circuit is immersed in liquid helium, and its frequency response from low frequency to several MHz is measured. The current gain and the noise spectrum with the HBT result in a signal-to-noise-ratio (SNR) that is a factor of 10-100 larger than without the HBT at lower frequencies. The transition frequency defined by SNR = 1 has been extended by as much as a factor of 10 compared to without the HBT amplification. The power dissipated by the HBT cryogenic pre-amplifier is approximately 5 nW to 5 μW for the investigated range of operation. The circuit is also operated in a single electron charge read-out configuration in the time-domain as a proof-of-principle demonstration of the amplification approach for single spin read-out.

Graphene-graphite oxide field-effect transistors.

PubMed

Standley, Brian; Mendez, Anthony; Schmidgall, Emma; Bockrath, Marc

2012-03-14

Graphene's high mobility and two-dimensional nature make it an attractive material for field-effect transistors. Previous efforts in this area have used bulk gate dielectric materials such as SiO(2) or HfO(2). In contrast, we have studied the use of an ultrathin layered material, graphene's insulating analogue, graphite oxide. We have fabricated transistors comprising single or bilayer graphene channels, graphite oxide gate insulators, and metal top-gates. The graphite oxide layers show relatively minimal leakage at room temperature. The breakdown electric field of graphite oxide was found to be comparable to SiO(2), typically ~1-3 × 10(8) V/m, while its dielectric constant is slightly higher, κ ≈ 4.3. © 2012 American Chemical Society

Imperceptible and Ultraflexible p-Type Transistors and Macroelectronics Based on Carbon Nanotubes.

PubMed

Cao, Xuan; Cao, Yu; Zhou, Chongwu

2016-01-26

Flexible thin-film transistors based on semiconducting single-wall carbon nanotubes are promising for flexible digital circuits, artificial skins, radio frequency devices, active-matrix-based displays, and sensors due to the outstanding electrical properties and intrinsic mechanical strength of carbon nanotubes. Nevertheless, previous research effort only led to nanotube thin-film transistors with the smallest bending radius down to 1 mm. In this paper, we have realized the full potential of carbon nanotubes by making ultraflexible and imperceptible p-type transistors and circuits with a bending radius down to 40 μm. In addition, the resulted transistors show mobility up to 12.04 cm(2) V(-1) S(-1), high on-off ratio (∼10(6)), ultralight weight (<3 g/m(2)), and good mechanical robustness (accommodating severe crumpling and 67% compressive strain). Furthermore, the nanotube circuits can operate properly with 33% compressive strain. On the basis of the aforementioned features, our ultraflexible p-type nanotube transistors and circuits have great potential to work as indispensable components for ultraflexible complementary electronics.

Silicon Field Effect Transistors as Dual-Use Sensor-Heater Hybrids

PubMed Central

Reddy, Bobby; Elibol, Oguz H.; Nair, Pradeep R.; Dorvel, Brian R.; Butler, Felice; Ahsan, Zahab; Bergstrom, Donald E.; Alam, Muhammad A.; Bashir, Rashid

2011-01-01

We demonstrate the temperature mediated applications of a previously proposed novel localized dielectric heating method on the surface of dual purpose silicon field effect transistor (FET) sensor-heaters and perform modeling and characterization of the underlying mechanisms. The FETs are first shown to operate as electrical sensors via sensitivity to changes in pH in ionic fluids. The same devices are then demonstrated as highly localized heaters via investigation of experimental heating profiles and comparison to simulation results. These results offer further insight into the heating mechanism and help determine the spatial resolution of the technique. Two important biosensor platform applications spanning different temperature ranges are then demonstrated: a localized heat-mediated DNA exchange reaction and a method for dense selective functionalization of probe molecules via the heat catalyzed complete desorption and reattachment of chemical functionalization to the transistor surfaces. Our results show that the use of silicon transistors can be extended beyond electrical switching and field-effect sensing to performing localized temperature controlled chemical reactions on the transistor itself. PMID:21214189

Microcrystalline silicon thin-film transistors for large area electronic applications

NASA Astrophysics Data System (ADS)

Chan, Kah-Yoong; Bunte, Eerke; Knipp, Dietmar; Stiebig, Helmut

2007-11-01

Thin-film transistors (TFTs) based on microcrystalline silicon (µc-Si:H) exhibit high charge carrier mobilities exceeding 35 cm2 V-1 s-1. The devices are fabricated by plasma-enhanced chemical vapor deposition at substrate temperatures below 200 °C. The fabrication process of the µc-Si:H TFTs is similar to the low temperature fabrication of amorphous silicon TFTs. The electrical characteristics of the µc-Si:H-based transistors will be presented. As the device charge carrier mobility of short channel TFTs is limited by the contacts, the influence of the drain and source contacts on the device parameters including the device charge carrier mobility and the device threshold voltage will be discussed. The experimental data will be described by a modified standard transistor model which accounts for the contact effects. Furthermore, the transmission line method was used to extract the device parameters including the contact resistance. The modified standard transistor model and the transmission line method will be compared in terms of the extracted device parameters and contact resistances.

High-mobility pyrene-based semiconductor for organic thin-film transistors.

PubMed

Cho, Hyunduck; Lee, Sunyoung; Cho, Nam Sung; Jabbour, Ghassan E; Kwak, Jeonghun; Hwang, Do-Hoon; Lee, Changhee

2013-05-01

Numerous conjugated oligoacenes and polythiophenes are being heavily studied in the search for high-mobility organic semiconductors. Although many researchers have designed fused aromatic compounds as organic semiconductors for organic thin-film transistors (OTFTs), pyrene-based organic semiconductors with high mobilities and on-off current ratios have not yet been reported. Here, we introduce a new pyrene-based p-type organic semiconductor showing liquid crystal behavior. The thin film characteristics of this material are investigated by varying the substrate temperature during the deposition and the gate dielectric condition using the surface modification with a self-assembled monolayer, and systematically studied in correlation with the performances of transistor devices with this compound. OTFT fabricated under the optimum deposition conditions of this compound, namely, 1,6-bis(5'-octyl-2,2'-bithiophen-5-yl)pyrene (BOBTP) shows a high-performance transistor behavior with a field-effect mobility of 2.1 cm(2) V(-1) s(-1) and an on-off current ratio of 7.6 × 10(6) and enhanced long-term stability compared to the pentacene thin-film transistor.

S-MMICs: Sub-mm-Wave Transistors and Integrated Circuits

DTIC Science & Technology

2008-09-01

Research Lab BAA DAAD19-03-R-0017 Research area 2.35: RF devices—Dr. Alfred Hung Submitted by: Mark Rodwell, Department of Electrical and Computer ...MOTIVATION / APPLICATION 3 TECHNOLOGY STATUS 4 TRANSISTOR SCALING LAWS 5 256 NM GENERATION 6 HBT POWER AMPLIFIER DEVELOPMENT 7 DRY-ETCHED EMITTER...TECHNOLOGY: 256 NM GENERATION 9 SCALED EPITAXY 11 CONCLUSIONS 12 20081103013 Executive Summary Transistor and power amplifier IC technology was

The four-gate transistor

NASA Technical Reports Server (NTRS)

Mojarradi, M. M.; Cristoveanu, S.; Allibert, F.; France, G.; Blalock, B.; Durfrene, B.

2002-01-01

The four-gate transistor or G4-FET combines MOSFET and JFET principles in a single SOI device. Experimental results reveal that each gate can modulate the drain current. Numerical simulations are presented to clarify the mechanisms of operation. The new device shows enhanced functionality, due to the combinatorial action of the four gates, and opens rather revolutionary applications.

Effect of temperature on the characteristics of silicon nanowire transistor.

PubMed

Hashim, Yasir; Sidek, Othman

2012-10-01

This paper presents the temperature characteristics of silicon nanowire transistors (SiNWTs) and examines the effect of temperature on transfer characteristics, threshold voltage, I(ON)/I(OFF) ratio, drain-induced barrier lowering (DIBL), and sub-threshold swing (SS). The (MuGFET) simulation tool was used to investigate the temperature characteristics of a transistor. The findings reveal the negative effect of higher working temperature on the use of SiNWTs in electronic circuits, such as digital circuits and amplifiers circuits, because of the lower I(ON)/I(OFF) ratio, higher DIBL, and higher SS at higher temperature. Moreover, the ON state is the optimum condition for using a transistor as a temperature nano-sensor.

Method for fabricating transistors using crystalline silicon devices on glass

DOEpatents

McCarthy, A.M.

1997-09-02

A method for fabricating transistors using single-crystal silicon devices on glass. This method overcomes the potential damage that may be caused to the device during high voltage bonding and employs a metal layer which may be incorporated as part of the transistor. This is accomplished such that when the bonding of the silicon wafer or substrate to the glass substrate is performed, the voltage and current pass through areas where transistors will not be fabricated. After removal of the silicon substrate, further metal may be deposited to form electrical contact or add functionality to the devices. By this method both single and gate-all-around devices may be formed. 13 figs.

GaN transistors on Si for switching and high-frequency applications

NASA Astrophysics Data System (ADS)

Ueda, Tetsuzo; Ishida, Masahiro; Tanaka, Tsuyoshi; Ueda, Daisuke

2014-10-01

In this paper, recent advances of GaN transistors on Si for switching and high-frequency applications are reviewed. Novel epitaxial structures including superlattice interlayers grown by metal organic chemical vapor deposition (MOCVD) relieve the strain and eliminate the cracks in the GaN over large-diameter Si substrates up to 8 in. As a new device structure for high-power switching application, Gate Injection Transistors (GITs) with a p-AlGaN gate over an AlGaN/GaN heterostructure successfully achieve normally-off operations maintaining high drain currents and low on-state resistances. Note that the GITs on Si are free from current collapse up to 600 V, by which the drain current would be markedly reduced after the application of high drain voltages. Highly efficient operations of an inverter and DC-DC converters are presented as promising applications of GITs for power switching. The high efficiencies in an inverter, a resonant LLC converter, and a point-of-load (POL) converter demonstrate the superior potential of the GaN transistors on Si. As for high-frequency transistors, AlGaN/GaN heterojuction field-effect transistors (HFETs) on Si designed specifically for microwave and millimeter-wave frequencies demonstrate a sufficiently high output power at these frequencies. Output powers of 203 W at 2.5 GHz and 10.7 W at 26.5 GHz are achieved by the fabricated GaN transistors. These devices for switching and high-frequency applications are very promising as future energy-efficient electronics because of their inherent low fabrication cost and superior device performance.

Systematic design methodology for robust genetic transistors based on I/O specifications via promoter-RBS libraries.

PubMed

Lee, Yi-Ying; Hsu, Chih-Yuan; Lin, Ling-Jiun; Chang, Chih-Chun; Cheng, Hsiao-Chun; Yeh, Tsung-Hsien; Hu, Rei-Hsing; Lin, Che; Xie, Zhen; Chen, Bor-Sen

2013-10-27

Synthetic genetic transistors are vital for signal amplification and switching in genetic circuits. However, it is still problematic to efficiently select the adequate promoters, Ribosome Binding Sides (RBSs) and inducer concentrations to construct a genetic transistor with the desired linear amplification or switching in the Input/Output (I/O) characteristics for practical applications. Three kinds of promoter-RBS libraries, i.e., a constitutive promoter-RBS library, a repressor-regulated promoter-RBS library and an activator-regulated promoter-RBS library, are constructed for systematic genetic circuit design using the identified kinetic strengths of their promoter-RBS components.According to the dynamic model of genetic transistors, a design methodology for genetic transistors via a Genetic Algorithm (GA)-based searching algorithm is developed to search for a set of promoter-RBS components and adequate concentrations of inducers to achieve the prescribed I/O characteristics of a genetic transistor. Furthermore, according to design specifications for different types of genetic transistors, a look-up table is built for genetic transistor design, from which we could easily select an adequate set of promoter-RBS components and adequate concentrations of external inducers for a specific genetic transistor. This systematic design method will reduce the time spent using trial-and-error methods in the experimental procedure for a genetic transistor with a desired I/O characteristic. We demonstrate the applicability of our design methodology to genetic transistors that have desirable linear amplification or switching by employing promoter-RBS library searching.

Systematic design methodology for robust genetic transistors based on I/O specifications via promoter-RBS libraries

PubMed Central

2013-01-01

Background Synthetic genetic transistors are vital for signal amplification and switching in genetic circuits. However, it is still problematic to efficiently select the adequate promoters, Ribosome Binding Sides (RBSs) and inducer concentrations to construct a genetic transistor with the desired linear amplification or switching in the Input/Output (I/O) characteristics for practical applications. Results Three kinds of promoter-RBS libraries, i.e., a constitutive promoter-RBS library, a repressor-regulated promoter-RBS library and an activator-regulated promoter-RBS library, are constructed for systematic genetic circuit design using the identified kinetic strengths of their promoter-RBS components. According to the dynamic model of genetic transistors, a design methodology for genetic transistors via a Genetic Algorithm (GA)-based searching algorithm is developed to search for a set of promoter-RBS components and adequate concentrations of inducers to achieve the prescribed I/O characteristics of a genetic transistor. Furthermore, according to design specifications for different types of genetic transistors, a look-up table is built for genetic transistor design, from which we could easily select an adequate set of promoter-RBS components and adequate concentrations of external inducers for a specific genetic transistor. Conclusion This systematic design method will reduce the time spent using trial-and-error methods in the experimental procedure for a genetic transistor with a desired I/O characteristic. We demonstrate the applicability of our design methodology to genetic transistors that have desirable linear amplification or switching by employing promoter-RBS library searching. PMID:24160305

65nm OPC and design optimization by using simple electrical transistor simulation

NASA Astrophysics Data System (ADS)

Trouiller, Yorick; Devoivre, Thierry; Belledent, Jerome; Foussadier, Franck; Borjon, Amandine; Patterson, Kyle; Lucas, Kevin; Couderc, Christophe; Sundermann, Frank; Urbani, Jean-Christophe; Baron, Stanislas; Rody, Yves; Chapon, Jean-Damien; Arnaud, Franck; Entradas, Jorge

2005-05-01

In the context of 65nm logic technology where gate CD control budget requirements are below 5nm, it is mandatory to properly quantify the impact of the 2D effects on the electrical behavior of the transistor [1,2]. This study uses the following sequence to estimate the impact on transistor performance: 1) A lithographic simulation is performed after OPC (Optical Proximity Correction) of active and poly using a calibrated model at best conditions. Some extrapolation of this model can also be used to assess marginalities due to process window (focus, dose, mask errors, and overlay). In our case study, we mainly checked the poly to active misalignment effects. 2) Electrical behavior of the transistor (Ion, Ioff, Vt) is calculated based on a derivative spice model using the simulated image of the gate as an input. In most of the cases Ion analysis, rather than Vt or leakage, gives sufficient information for patterning optimization. We have demonstrated the benefit of this approach with two different examples: -design rule trade-off : we estimated the impact with and without misalignment of critical rules like poly corner to active distance, active corner to poly distance or minimum space between small transistor and big transistor. -Library standard cell debugging: we applied this methodology to the most critical one hundred transistors of our standard cell libraries and calculate Ion behavior with and without misalignment between active and poly. We compared two scanner illumination modes and two OPC versions based on the behavior of the one hundred transistors. We were able to see the benefits of one illumination, and also the improvement in the OPC maturity.

High-Power, High-Frequency Si-Based (SiGe) Transistors Developed

NASA Technical Reports Server (NTRS)

Ponchak, George E.

2002-01-01

Future NASA, DOD, and commercial products will require electronic circuits that have greater functionality and versatility but occupy less space and cost less money to build and integrate than current products. System on a Chip (SOAC), a single semiconductor substrate containing circuits that perform many functions or containing an entire system, is widely recognized as the best technology for achieving low-cost, small-sized systems. Thus, a circuit technology is required that can gather, process, store, and transmit data or communications. Since silicon-integrated circuits are already used for data processing and storage and the infrastructure that supports silicon circuit fabrication is very large, it is sensible to develop communication circuits on silicon so that all the system functions can be integrated onto a single wafer. Until recently, silicon integrated circuits did not function well at the frequencies required for wireless or microwave communications, but with the introduction of small amounts of germanium into the silicon to make silicon-germanium (SiGe) transistors, silicon-based communication circuits are possible. Although microwavefrequency SiGe circuits have been demonstrated, there has been difficulty in obtaining the high power from their transistors that is required for the amplifiers of a transmitter, and many researchers have thought that this could not be done. The NASA Glenn Research Center and collaborators at the University of Michigan have developed SiGe transistors and amplifiers with state-of-the-art output power at microwave frequencies from 8 to 20 GHz. These transistors are fabricated using standard silicon processing and may be integrated with CMOS integrated circuits on a single chip. A scanning electron microscope image of a typical SiGe heterojunction bipolar transistor is shown in the preceding photomicrograph. This transistor achieved a record output power of 550 mW and an associated power-added efficiency of 33 percent at 8

Photocurrent spectroscopy of pentacene thin film transistors

NASA Astrophysics Data System (ADS)

Breban, Mihaela

We demonstrate the application of photocurrent modulation spectroscopy in characterizing the performance of organic thin-film transistors. A parallel analysis of the direct current and photocurrent voltage characteristics provides a model free determination of the field-effect mobility and the density of free carriers in the transistor channel as a function of the applied gate voltage. Applying this technique to pentacene thin-film transistors demonstrates that the mobility increases as V1/3g . The free-carrier density is approximately 1/10 of the expected capacitive charge, and the mobility increases monotonically with the free carrier density, consistent with the trap and release model of transport. Also, the modulated photocurrent spectroscopy can be used as a probe of defect states in pentacene thin film transistors, measuring simultaneously the magnitude and the phase of the photocurrent as a function of the modulation frequency. This is accomplished by modeling the photo-carrier generation process as exciton dissociation via interaction with localized traps. Experimental data reveal a Gaussian distribution of localized states centered around 0.3 eV above the highest occupied molecular orbital. We also investigated the effect of the gate dielectric material with our probe and found that the position of the extracted Gaussian slightly shifts, consistent with the expected image charge effect for Pn through the dielectric substrate. Also shifts in the Gaussian position for samples fabricated with variable deposition conditions are correlated with changes in Pn morphology. The morphological differences between Pn films were also detected in current-voltage characteristics and photocurrent spectra. However, the origin of the ubiquitous 0.3 eV defect in Pn seems to be unrelated to structural differences in Pn films.

Influence of polymer dielectrics on C60-based field-effect transistors

NASA Astrophysics Data System (ADS)

Zhou, Jianlin; Zhang, Fujia; Lan, Lifeng; Wen, Shangsheng; Peng, Junbiao

2007-12-01

Fullerene C60 organic field-effect transistors (OFETs) have been fabricated based on two different polymer dielectric materials, poly(methylmethacrylate) (PMMA) and cross-linkable poly(4-vinylphenol). The large grain size of C60 film and small number of traps at the interface of PMMA /C60 were obtained with high electron mobility of 0.66cm2/Vs in the PMMA transistor. The result suggests that the C60 semiconductor cooperating with polymer dielectric is a promising application in the fabrication of n-type organic transistors because of low threshold voltage and high electron mobility.

Multibit data storage states formed in plasma-treated MoS₂ transistors.

PubMed

Chen, Mikai; Nam, Hongsuk; Wi, Sungjin; Priessnitz, Greg; Gunawan, Ivan Manuel; Liang, Xiaogan

2014-04-22

New multibit memory devices are desirable for improving data storage density and computing speed. Here, we report that multilayer MoS2 transistors, when treated with plasmas, can dramatically serve as low-cost, nonvolatile, highly durable memories with binary and multibit data storage capability. We have demonstrated binary and 2-bit/transistor (or 4-level) data states suitable for year-scale data storage applications as well as 3-bit/transistor (or 8-level) data states for day-scale data storage. This multibit memory capability is hypothesized to be attributed to plasma-induced doping and ripple of the top MoS2 layers in a transistor, which could form an ambipolar charge-trapping layer interfacing the underlying MoS2 channel. This structure could enable the nonvolatile retention of charged carriers as well as the reversible modulation of polarity and amount of the trapped charge, ultimately resulting in multilevel data states in memory transistors. Our Kelvin force microscopy results strongly support this hypothesis. In addition, our research suggests that the programming speed of such memories can be improved by using nanoscale-area plasma treatment. We anticipate that this work would provide important scientific insights for leveraging the unique structural property of atomically layered two-dimensional materials in nanoelectronic applications.

Organic field-effect transistors using single crystals

PubMed Central

Hasegawa, Tatsuo; Takeya, Jun

2009-01-01

Organic field-effect transistors using small-molecule organic single crystals are developed to investigate fundamental aspects of organic thin-film transistors that have been widely studied for possible future markets for ‘plastic electronics’. In reviewing the physics and chemistry of single-crystal organic field-effect transistors (SC-OFETs), the nature of intrinsic charge dynamics is elucidated for the carriers induced at the single crystal surfaces of molecular semiconductors. Materials for SC-OFETs are first reviewed with descriptions of the fabrication methods and the field-effect characteristics. In particular, a benchmark carrier mobility of 20–40 cm2 Vs−1, achieved with thin platelets of rubrene single crystals, demonstrates the significance of the SC-OFETs and clarifies material limitations for organic devices. In the latter part of this review, we discuss the physics of microscopic charge transport by using SC-OFETs at metal/semiconductor contacts and along semiconductor/insulator interfaces. Most importantly, Hall effect and electron spin resonance (ESR) measurements reveal that interface charge transport in molecular semiconductors is properly described in terms of band transport and localization by charge traps. PMID:27877287

A pattern recognition approach to transistor array parameter variance

NASA Astrophysics Data System (ADS)

da F. Costa, Luciano; Silva, Filipi N.; Comin, Cesar H.

2018-06-01

The properties of semiconductor devices, including bipolar junction transistors (BJTs), are known to vary substantially in terms of their parameters. In this work, an experimental approach, including pattern recognition concepts and methods such as principal component analysis (PCA) and linear discriminant analysis (LDA), was used to experimentally investigate the variation among BJTs belonging to integrated circuits known as transistor arrays. It was shown that a good deal of the devices variance can be captured using only two PCA axes. It was also verified that, though substantially small variation of parameters is observed for BJT from the same array, larger variation arises between BJTs from distinct arrays, suggesting the consideration of device characteristics in more critical analog designs. As a consequence of its supervised nature, LDA was able to provide a substantial separation of the BJT into clusters, corresponding to each transistor array. In addition, the LDA mapping into two dimensions revealed a clear relationship between the considered measurements. Interestingly, a specific mapping suggested by the PCA, involving the total harmonic distortion variation expressed in terms of the average voltage gain, yielded an even better separation between the transistor array clusters. All in all, this work yielded interesting results from both semiconductor engineering and pattern recognition perspectives.

Apparatus and method for recharging a string a avalanche transistors within a pulse generator

DOEpatents

Fulkerson, E. Stephen

2000-01-01

An apparatus and method for recharging a string of avalanche transistors within a pulse generator is disclosed. A plurality of amplification stages are connected in series. Each stage includes an avalanche transistor and a capacitor. A trigger signal, causes the apparatus to generate a very high voltage pulse of a very brief duration which discharges the capacitors. Charge resistors inject current into the string of avalanche transistors at various points, recharging the capacitors. The method of the present invention includes the steps of supplying current to charge resistors from a power supply; using the charge resistors to charge capacitors connected to a set of serially connected avalanche transistors; triggering the avalanche transistors; generating a high-voltage pulse from the charge stored in the capacitors; and recharging the capacitors through the charge resistors.

Combinatorial study of zinc tin oxide thin-film transistors

NASA Astrophysics Data System (ADS)

McDowell, M. G.; Sanderson, R. J.; Hill, I. G.

2008-01-01

Groups of thin-film transistors using a zinc tin oxide semiconductor layer have been fabricated via a combinatorial rf sputtering technique. The ZnO :SnO2 ratio of the film varies as a function of position on the sample, from pure ZnO to SnO2, allowing for a study of zinc tin oxide transistor performance as a function of channel stoichiometry. The devices were found to have mobilities ranging from 2to12cm2/Vs, with two peaks in mobility in devices at ZnO fractions of 0.80±0.03 and 0.25±0.05, and on/off ratios as high as 107. Transistors composed predominantly of SnO2 were found to exhibit light sensitivity which affected both the on/off ratios and threshold voltages of these devices.

Voltage Amplifier Based on Organic Electrochemical Transistor.

PubMed

Braendlein, Marcel; Lonjaret, Thomas; Leleux, Pierre; Badier, Jean-Michel; Malliaras, George G

2017-01-01

Organic electrochemical transistors (OECTs) are receiving a great deal of attention as amplifying transducers for electrophysiology. A key limitation of this type of transistors, however, lies in the fact that their output is a current, while most electrophysiology equipment requires a voltage input. A simple circuit is built and modeled that uses a drain resistor to produce a voltage output. It is shown that operating the OECT in the saturation regime provides increased sensitivity while maintaining a linear signal transduction. It is demonstrated that this circuit provides high quality recordings of the human heart using readily available electrophysiology equipment, paving the way for the use of OECTs in the clinic.

Graphene Field Effect Transistor for Radiation Detection

NASA Technical Reports Server (NTRS)

Li, Mary J. (Inventor); Chen, Zhihong (Inventor)

2016-01-01

The present invention relates to a graphene field effect transistor-based radiation sensor for use in a variety of radiation detection applications, including manned spaceflight missions. The sensing mechanism of the radiation sensor is based on the high sensitivity of graphene in the local change of electric field that can result from the interaction of ionizing radiation with a gated undoped silicon absorber serving as the supporting substrate in the graphene field effect transistor. The radiation sensor has low power and high sensitivity, a flexible structure, and a wide temperature range, and can be used in a variety of applications, particularly in space missions for human exploration.

Total Dose Effects in Conventional Bipolar Transistors

NASA Technical Reports Server (NTRS)

Johnston, A. H.; Swift, G. W.; Rax, B. G.

1994-01-01

This paper examines various factors in bipolar device construction and design, and discusses their impact on radiation hardness. The intent of the paper is to improve understanding of the underlying mechanisms for practical devices without special test structures, and to provide (1) guidance in ways to select transistor designs that are more resistant to radiation damage, and (2) methods to estimate the maximum amount of damage that might be expected from a basic transistor design. The latter factor is extremely important in assessing the risk that future lots of devices will be substantially below design limits, which are usually based on test data for older devices.

Organic transistors for electrophysiology (Presentation Recording)

NASA Astrophysics Data System (ADS)

Rivnay, Jonathan

2015-10-01

Efficient local transduction of biological signals is of critical importance for mapping brain activity and diagnosing pathological conditions. Traditional devices used to record electrophysiological signals are passive electrodes that require (pre)amplification with downstream electronics. Organic electrochemical transistors (OECTs) that utilize conducting polymer films as the channel have shown considerable promise as amplifying transducers due to their stability in aqueous conditions and high transconductance (>3 mS). The materials properties and physics of such transistors, however, remains largely unexplored thus limiting their potential. Here we show that the uptake of ionic charge from an electrolyte into a poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) OECT channel leads to a dependence of the effective capacitance on the entire volume of the film. Subsequently, device transconductance and time response vary with channel thickness, a defining characteristic that differentiates OECTs from field effect transistors, and provides a new degree of freedom for device engineering. Using this understanding we tailor OECTs for a variety of low (1-100 Hz) and high (1-10 kHz) frequency applications, including human electroencephalography, where high transconductance devices impart richer signal content without the need for additional amplification circuitry. We also show that the materials figure of merit OECTs is the product of hole mobility and volumetric capacitance of the channel, leading to design rules for novel high performance materials.

Quasi-Solid-State Single-Atom Transistors.

PubMed

Xie, Fangqing; Peukert, Andreas; Bender, Thorsten; Obermair, Christian; Wertz, Florian; Schmieder, Philipp; Schimmel, Thomas

2018-06-21

The single-atom transistor represents a quantum electronic device at room temperature, allowing the switching of an electric current by the controlled and reversible relocation of one single atom within a metallic quantum point contact. So far, the device operates by applying a small voltage to a control electrode or "gate" within the aqueous electrolyte. Here, the operation of the atomic device in the quasi-solid state is demonstrated. Gelation of pyrogenic silica transforms the electrolyte into the quasi-solid state, exhibiting the cohesive properties of a solid and the diffusive properties of a liquid, preventing the leakage problem and avoiding the handling of a liquid system. The electrolyte is characterized by cyclic voltammetry, conductivity measurements, and rotation viscometry. Thus, a first demonstration of the single-atom transistor operating in the quasi-solid-state is given. The silver single-atom and atomic-scale transistors in the quasi-solid-state allow bistable switching between zero and quantized conductance levels, which are integer multiples of the conductance quantum G 0  = 2e 2 /h. Source-drain currents ranging from 1 to 8 µA are applied in these experiments. Any obvious influence of the gelation of the aqueous electrolyte on the electron transport within the quantum point contact is not observed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Deformable Organic Nanowire Field-Effect Transistors.

PubMed

Lee, Yeongjun; Oh, Jin Young; Kim, Taeho Roy; Gu, Xiaodan; Kim, Yeongin; Wang, Ging-Ji Nathan; Wu, Hung-Chin; Pfattner, Raphael; To, John W F; Katsumata, Toru; Son, Donghee; Kang, Jiheong; Matthews, James R; Niu, Weijun; He, Mingqian; Sinclair, Robert; Cui, Yi; Tok, Jeffery B-H; Lee, Tae-Woo; Bao, Zhenan

2018-02-01

Deformable electronic devices that are impervious to mechanical influence when mounted on surfaces of dynamically changing soft matters have great potential for next-generation implantable bioelectronic devices. Here, deformable field-effect transistors (FETs) composed of single organic nanowires (NWs) as the semiconductor are presented. The NWs are composed of fused thiophene diketopyrrolopyrrole based polymer semiconductor and high-molecular-weight polyethylene oxide as both the molecular binder and deformability enhancer. The obtained transistors show high field-effect mobility >8 cm 2 V -1 s -1 with poly(vinylidenefluoride-co-trifluoroethylene) polymer dielectric and can easily be deformed by applied strains (both 100% tensile and compressive strains). The electrical reliability and mechanical durability of the NWs can be significantly enhanced by forming serpentine-like structures of the NWs. Remarkably, the fully deformable NW FETs withstand 3D volume changes (>1700% and reverting back to original state) of a rubber balloon with constant current output, on the surface of which it is attached. The deformable transistors can robustly operate without noticeable degradation on a mechanically dynamic soft matter surface, e.g., a pulsating balloon (pulse rate: 40 min -1 (0.67 Hz) and 40% volume expansion) that mimics a beating heart, which underscores its potential for future biomedical applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Specifics of Pulsed Arc Welding Power Supply Performance Based On A Transistor Switch

NASA Astrophysics Data System (ADS)

Krampit, N. Yu; Kust, T. S.; Krampit, M. A.

2016-08-01

Specifics of designing a pulsed arc welding power supply device are presented in the paper. Electronic components for managing large current was analyzed. Strengths and shortcomings of power supply circuits based on thyristor, bipolar transistor and MOSFET are outlined. As a base unit for pulsed arc welding was chosen MOSFET transistor, which is easy to manage. Measures to protect a transistor are given. As for the transistor control device is a microcontroller Arduino which has a low cost and adequate performance of the work. Bead transfer principle is to change the voltage on the arc in the formation of beads on the wire end. Microcontroller controls transistor when the arc voltage reaches the threshold voltage. Thus there is a separation and transfer of beads without splashing. Control strategies tested on a real device and presented. The error in the operation of the device is less than 25 us, it can be used controlling drop transfer at high frequencies (up to 1300 Hz).

Fe3O4 nanoparticles and nanocomposites with potential application in biomedicine and in communication technologies: Nanoparticle aggregation, interaction, and effective magnetic anisotropy

NASA Astrophysics Data System (ADS)

Allia, P.; Barrera, G.; Tiberto, P.; Nardi, T.; Leterrier, Y.; Sangermano, M.

2014-09-01

Magnetite nanoparticles with a size of 5-6 nm with potential impact on biomedicine and information/communication technologies were synthesized by thermal decomposition of Fe(acac)3 and subsequently coated with a silica shell exploiting a water-in-oil synthetic procedure. The as-produced powders (comprised of either Fe3O4 or Fe3O4@silica nanoparticles) were mixed with a photocurable resin obtaining two magnetic nanocomposites with the same nominal amount of magnetic material. The static magnetic properties of the two nanopowders and the corresponding nanocomposites were measured in the 10 K-300 K temperature range. Magnetic measurements are shown here to be able to give unambiguous information on single-particle properties such as particle size and magnetic anisotropy as well as on nanoparticle aggregation and interparticle interaction. A comparison between the size distribution functions obtained from magnetic measurements and from TEM images shows that figures estimated from properly analyzed magnetic measurements are very close to the actual values. In addition, the present analysis allows us to determine the value of the effective magnetic anisotropy and to estimate the anisotropy contribution from the surface. The Field-cooled/zero field cooled curves reveal a high degree of particle aggregation in the Fe3O4 nanopowder, which is partially reduced by silica coating and strongly decreased by dissolution in the host polymer. In all considered materials, the nanoparticles are magnetically interacting, the interaction strength being a function of nanoparticle environment and being the lowest in the nanocomposite containing bare, well-separate Fe3O4 particles. All samples behave as interacting superparamagnetic materials instead of ideal superparamagnets and follow the corresponding scaling law.

Heterojunction bipolar transistor technology for data acquisition and communication

NASA Technical Reports Server (NTRS)

Wang, C.; Chang, M.; Beccue, S.; Nubling, R.; Zampardi, P.; Sheng, N.; Pierson, R.

1992-01-01

Heterojunction Bipolar Transistor (HBT) technology has emerged as one of the most promising technologies for ultrahigh-speed integrated circuits. HBT circuits for digital and analog applications, data conversion, and power amplification have been realized, with speed performance well above 20 GHz. At Rockwell, a baseline AlGaAs/GaAs HBT technology has been established in a manufacturing facility. This paper describes the HBT technology, transistor characteristics, and HBT circuits for data acquisition and communication.

Dramatic switching behavior in suspended MoS2 field-effect transistors

NASA Astrophysics Data System (ADS)

Chen, Huawei; Li, Jingyu; Chen, Xiaozhang; Zhang, David; Zhou, Peng

2018-02-01

When integrating MoS2 flakes into scaling-down transistors, the short-channel effect, which is severe in silicon technology below 5-nanometer, can be avoided effectively. MoS2 transistors not only exhibit a high on/off ratio but also demonstrate a rapid switching speed. According to the theoretical calculation, the thermionic limit subthreshold slope (SS) of the ideal device could reach 60 mV/dec. However, due to the confinement of defects from substrates or contamination during the process, the SS deteriorates to more than 300 mV/dec, causing serious power consumption. In this work, we optimize the SS through structure design of MoS2 transistors. The suspended transistors exhibit a high on/off ratio of 107 and a minimum SS of 63 mV/dec with an ultralow standby power at room temperature. This study demonstrates the promising potential of structure design for electronic devices with ultralow-power switching behaviors.

Fabrication of fully transparent nanowire transistors for transparent and flexible electronics

NASA Astrophysics Data System (ADS)

Ju, Sanghyun; Facchetti, Antonio; Xuan, Yi; Liu, Jun; Ishikawa, Fumiaki; Ye, Peide; Zhou, Chongwu; Marks, Tobin J.; Janes, David B.

2007-06-01

The development of optically transparent and mechanically flexible electronic circuitry is an essential step in the effort to develop next-generation display technologies, including `see-through' and conformable products. Nanowire transistors (NWTs) are of particular interest for future display devices because of their high carrier mobilities compared with bulk or thin-film transistors made from the same materials, the prospect of processing at low temperatures compatible with plastic substrates, as well as their optical transparency and inherent mechanical flexibility. Here we report fully transparent In2O3 and ZnO NWTs fabricated on both glass and flexible plastic substrates, exhibiting high-performance n-type transistor characteristics with ~82% optical transparency. These NWTs should be attractive as pixel-switching and driving transistors in active-matrix organic light-emitting diode (AMOLED) displays. The transparency of the entire pixel area should significantly enhance aperture ratio efficiency in active-matrix arrays and thus substantially decrease power consumption.

Fabrication of fully transparent nanowire transistors for transparent and flexible electronics.

PubMed

Ju, Sanghyun; Facchetti, Antonio; Xuan, Yi; Liu, Jun; Ishikawa, Fumiaki; Ye, Peide; Zhou, Chongwu; Marks, Tobin J; Janes, David B

2007-06-01

The development of optically transparent and mechanically flexible electronic circuitry is an essential step in the effort to develop next-generation display technologies, including 'see-through' and conformable products. Nanowire transistors (NWTs) are of particular interest for future display devices because of their high carrier mobilities compared with bulk or thin-film transistors made from the same materials, the prospect of processing at low temperatures compatible with plastic substrates, as well as their optical transparency and inherent mechanical flexibility. Here we report fully transparent In(2)O(3) and ZnO NWTs fabricated on both glass and flexible plastic substrates, exhibiting high-performance n-type transistor characteristics with approximately 82% optical transparency. These NWTs should be attractive as pixel-switching and driving transistors in active-matrix organic light-emitting diode (AMOLED) displays. The transparency of the entire pixel area should significantly enhance aperture ratio efficiency in active-matrix arrays and thus substantially decrease power consumption.

Analysing black phosphorus transistors using an analytic Schottky barrier MOSFET model.

PubMed

Penumatcha, Ashish V; Salazar, Ramon B; Appenzeller, Joerg

2015-11-13

Owing to the difficulties associated with substitutional doping of low-dimensional nanomaterials, most field-effect transistors built from carbon nanotubes, two-dimensional crystals and other low-dimensional channels are Schottky barrier MOSFETs (metal-oxide-semiconductor field-effect transistors). The transmission through a Schottky barrier-MOSFET is dominated by the gate-dependent transmission through the Schottky barriers at the metal-to-channel interfaces. This makes the use of conventional transistor models highly inappropriate and has lead researchers in the past frequently to extract incorrect intrinsic properties, for example, mobility, for many novel nanomaterials. Here we propose a simple modelling approach to quantitatively describe the transfer characteristics of Schottky barrier-MOSFETs from ultra-thin body materials accurately in the device off-state. In particular, after validating the model through the analysis of a set of ultra-thin silicon field-effect transistor data, we have successfully applied our approach to extract Schottky barrier heights for electrons and holes in black phosphorus devices for a large range of body thicknesses.

Hybrid light emitting transistors (Presentation Recording)

NASA Astrophysics Data System (ADS)

Muhieddine, Khalid; Ullah, Mujeeb; Namdas, Ebinazar B.; Burn, Paul L.

2015-10-01

Organic light-emitting diodes (OLEDs) are well studied and established in current display applications. Light-emitting transistors (LETs) have been developed to further simplify the necessary circuitry for these applications, combining the switching capabilities of a transistor with the light emitting capabilities of an OLED. Such devices have been studied using mono- and bilayer geometries and a variety of polymers [1], small organic molecules [2] and single crystals [3] within the active layers. Current devices can often suffer from low carrier mobilities and most operate in p-type mode due to a lack of suitable n-type organic charge carrier materials. Hybrid light-emitting transistors (HLETs) are a logical step to improve device performance by harnessing the charge carrier capabilities of inorganic semiconductors [4]. We present state of the art, all solution processed hybrid light-emitting transistors using a non-planar contact geometry [1, 5]. We will discuss HLETs comprised of an inorganic electron transport layer prepared from a sol-gel of zinc tin oxide and several organic emissive materials. The mobility of the devices is found between 1-5 cm2/Vs and they had on/off ratios of ~105. Combined with optical brightness and efficiencies of the order of 103 cd/m2 and 10-3-10-1 %, respectively, these devices are moving towards the performance required for application in displays. [1] M. Ullah, K. Tandy, S. D. Yambem, M. Aljada, P. L. Burn, P. Meredith, E. B. Namdas., Adv. Mater. 2013, 25, 53, 6213 [2] R. Capelli, S. Toffanin, G. Generali, H. Usta, A. Facchetti, M. Muccini, Nature Materials 2010, 9, 496 [3] T. Takenobu, S. Z. Bisri, T. Takahashi, M. Yahiro, C. Adachi, Y. Iwasa, Phys. Rev. Lett. 2008, 100, 066601 [4] H. Nakanotani, M. Yahiro, C. Adachi, K. Yano, Appl. Phys. Lett. 2007, 90, 262104 [5] K. Muhieddine, M. Ullah, B. N. Pal, P. Burn E. B. Namdas, Adv. Mater. 2014, 26,37, 6410

Maskless writing of a flexible nanoscale transistor with Au-contacted carbon nanotube electrodes

NASA Astrophysics Data System (ADS)

Dockendorf, Cedric P. R.; Poulikakos, Dimos; Hwang, Gilgueng; Nelson, Bradley J.; Grigoropoulos, Costas P.

2007-12-01

A flexible polymer field effect transistor with a nanoscale carbon nanotube channel is conceptualized and realized herein. Carbon nanotubes (CNTs) were dispersed on a polyimide substrate and marked in an scanning electron microscope with focused ion beam such that they could be contacted with gold nanoink. The CNTs were divided into two parts forming the source and drain of the transistor. A micropipette writing method was used to contact the carbon nanotube electrodes with gold nanoink and to deposit the poly(3-hexylthiophene) as an active layer. The mobility of the transistors is of the order of 10-5cm/Vs. After fabrication, the flexible transistors can be peeled off the substrate.

Low-power bacteriorhodopsin-silicon n-channel metal-oxide field-effect transistor photoreceiver.

PubMed

Shin, Jonghyun; Bhattacharya, Pallab; Yuan, Hao-Chih; Ma, Zhenqiang; Váró, György

2007-03-01

A bacteriorhodopsin (bR)-silicon n-channel metal-oxide field-effect transistor (NMOSFET) monolithically integrated photoreceiver is demonstrated. The bR film is selectively formed on an external gate electrode of the transistor by electrophoretic deposition. A modified biasing circuit is incorporated, which helps to match the resistance of the bR film to the input impedance of the NMOSFET and to shift the operating point of the transistor to coincide with the maximum gain. The photoreceiver exhibits a responsivity of 4.7 mA/W.

Chaos Quantum-Behaved Cat Swarm Optimization Algorithm and Its Application in the PV MPPT

PubMed Central

2017-01-01

Cat Swarm Optimization (CSO) algorithm was put forward in 2006. Despite a faster convergence speed compared with Particle Swarm Optimization (PSO) algorithm, the application of CSO is greatly limited by the drawback of “premature convergence,” that is, the possibility of trapping in local optimum when dealing with nonlinear optimization problem with a large number of local extreme values. In order to surmount the shortcomings of CSO, Chaos Quantum-behaved Cat Swarm Optimization (CQCSO) algorithm is proposed in this paper. Firstly, Quantum-behaved Cat Swarm Optimization (QCSO) algorithm improves the accuracy of the CSO algorithm, because it is easy to fall into the local optimum in the later stage. Chaos Quantum-behaved Cat Swarm Optimization (CQCSO) algorithm is proposed by introducing tent map for jumping out of local optimum in this paper. Secondly, CQCSO has been applied in the simulation of five different test functions, showing higher accuracy and less time consumption than CSO and QCSO. Finally, photovoltaic MPPT model and experimental platform are established and global maximum power point tracking control strategy is achieved by CQCSO algorithm, the effectiveness and efficiency of which have been verified by both simulation and experiment. PMID:29181020

Chaos Quantum-Behaved Cat Swarm Optimization Algorithm and Its Application in the PV MPPT.

PubMed

Nie, Xiaohua; Wang, Wei; Nie, Haoyao

2017-01-01

Cat Swarm Optimization (CSO) algorithm was put forward in 2006. Despite a faster convergence speed compared with Particle Swarm Optimization (PSO) algorithm, the application of CSO is greatly limited by the drawback of "premature convergence," that is, the possibility of trapping in local optimum when dealing with nonlinear optimization problem with a large number of local extreme values. In order to surmount the shortcomings of CSO, Chaos Quantum-behaved Cat Swarm Optimization (CQCSO) algorithm is proposed in this paper. Firstly, Quantum-behaved Cat Swarm Optimization (QCSO) algorithm improves the accuracy of the CSO algorithm, because it is easy to fall into the local optimum in the later stage. Chaos Quantum-behaved Cat Swarm Optimization (CQCSO) algorithm is proposed by introducing tent map for jumping out of local optimum in this paper. Secondly, CQCSO has been applied in the simulation of five different test functions, showing higher accuracy and less time consumption than CSO and QCSO. Finally, photovoltaic MPPT model and experimental platform are established and global maximum power point tracking control strategy is achieved by CQCSO algorithm, the effectiveness and efficiency of which have been verified by both simulation and experiment.

Low Temperature Photoluminescence (PL) from High Electron Mobility Transistors (HEMTs)

DTIC Science & Technology

2015-03-01

Photoluminescence Form InxAl1-xN Films Deposited by Plasma-Assisted Molecular Beam Epitaxy ,” Submitted to Applied Physics Letters, July 2014. 8 LIST OF...TECHNICAL REPORT RDMR-WD-14-55 LOW TEMPERATURE PHOTOLUMINESCENCE (PL) FROM HIGH ELECTRON MOBILITY TRANSISTORS ( HEMTS ...Mobility Transistors ( HEMTs ) 5. FUNDING NUMBERS 6. AUTHOR(S) Adam T. Roberts and Henry O. Everitt 7. PERFORMING ORGANIZATION NAME(S

Direct observation of single-charge-detection capability of nanowire field-effect transistors.

PubMed

Salfi, J; Savelyev, I G; Blumin, M; Nair, S V; Ruda, H E

2010-10-01

A single localized charge can quench the luminescence of a semiconductor nanowire, but relatively little is known about the effect of single charges on the conductance of the nanowire. In one-dimensional nanostructures embedded in a material with a low dielectric permittivity, the Coulomb interaction and excitonic binding energy are much larger than the corresponding values when embedded in a material with the same dielectric permittivity. The stronger Coulomb interaction is also predicted to limit the carrier mobility in nanowires. Here, we experimentally isolate and study the effect of individual localized electrons on carrier transport in InAs nanowire field-effect transistors, and extract the equivalent charge sensitivity. In the low carrier density regime, the electrostatic potential produced by one electron can create an insulating weak link in an otherwise conducting nanowire field-effect transistor, modulating its conductance by as much as 4,200% at 31 K. The equivalent charge sensitivity, 4 × 10(-5) e Hz(-1/2) at 25 K and 6 × 10(-5) e Hz(-1/2) at 198 K, is orders of magnitude better than conventional field-effect transistors and nanoelectromechanical systems, and is just a factor of 20-30 away from the record sensitivity for state-of-the-art single-electron transistors operating below 4 K (ref. 8). This work demonstrates the feasibility of nanowire-based single-electron memories and illustrates a physical process of potential relevance for high performance chemical sensors. The charge-state-detection capability we demonstrate also makes the nanowire field-effect transistor a promising host system for impurities (which may be introduced intentionally or unintentionally) with potentially long spin lifetimes, because such transistors offer more sensitive spin-to-charge conversion readout than schemes based on conventional field-effect transistors.

Conducting glasses recovered from thin film transistor liquid crystal display wastes for dye-sensitized solar cell cathodes.

PubMed

Chen, C-C; Chang, F-C; Peng, C Y; Wang, H Paul

2015-01-01

Transparent conductive glasses such as thin film transistor (TFT) array and colour filter glasses were recovered from the TFT-liquid crystal display panel wastes by dismantling and sonic cleaning. Noble metals (i.e. platinum (Pt)) and indium tin oxide (ITO) are generally used in the cathode of a dye-sensitized solar cell (DSSC). To reduce the DSSC cost, Pt was replaced with nano nickel-encapsulated carbon-shell (Ni@C) nanoparticles, which were prepared by carbonization of Ni²⁺-β-cyclodextrin at 673 K for 2 h. The recovered conductive glasses were used in the DSSC electrodes in the substitution of relatively expensive ITO. Interestingly, the efficiency of the DSSC having the Ni@C-coated cathode is as high as 2.54%. Moreover, the cost of the DSSC using the recovered materials can be reduced by at least 24%.

BEHAVE: fire behavior prediction and fuel modeling system-BURN Subsystem, part 1

Treesearch

Patricia L. Andrews

1986-01-01

Describes BURN Subsystem, Part 1, the operational fire behavior prediction subsystem of the BEHAVE fire behavior prediction and fuel modeling system. The manual covers operation of the computer program, assumptions of the mathematical models used in the calculations, and application of the predictions.

Two-Photon Functional Imaging of the Auditory Cortex in Behaving Mice: From Neural Networks to Single Spines.

PubMed

Li, Ruijie; Wang, Meng; Yao, Jiwei; Liang, Shanshan; Liao, Xiang; Yang, Mengke; Zhang, Jianxiong; Yan, Junan; Jia, Hongbo; Chen, Xiaowei; Li, Xingyi

2018-01-01

In vivo two-photon Ca 2+ imaging is a powerful tool for recording neuronal activities during perceptual tasks and has been increasingly applied to behaving animals for acute or chronic experiments. However, the auditory cortex is not easily accessible to imaging because of the abundant temporal muscles, arteries around the ears and their lateral locations. Here, we report a protocol for two-photon Ca 2+ imaging in the auditory cortex of head-fixed behaving mice. By using a custom-made head fixation apparatus and a head-rotated fixation procedure, we achieved two-photon imaging and in combination with targeted cell-attached recordings of auditory cortical neurons in behaving mice. Using synthetic Ca 2+ indicators, we recorded the Ca 2+ transients at multiple scales, including neuronal populations, single neurons, dendrites and single spines, in auditory cortex during behavior. Furthermore, using genetically encoded Ca 2+ indicators (GECIs), we monitored the neuronal dynamics over days throughout the process of associative learning. Therefore, we achieved two-photon functional imaging at multiple scales in auditory cortex of behaving mice, which extends the tool box for investigating the neural basis of audition-related behaviors.

Two-Photon Functional Imaging of the Auditory Cortex in Behaving Mice: From Neural Networks to Single Spines

PubMed Central

Li, Ruijie; Wang, Meng; Yao, Jiwei; Liang, Shanshan; Liao, Xiang; Yang, Mengke; Zhang, Jianxiong; Yan, Junan; Jia, Hongbo; Chen, Xiaowei; Li, Xingyi

2018-01-01

In vivo two-photon Ca2+ imaging is a powerful tool for recording neuronal activities during perceptual tasks and has been increasingly applied to behaving animals for acute or chronic experiments. However, the auditory cortex is not easily accessible to imaging because of the abundant temporal muscles, arteries around the ears and their lateral locations. Here, we report a protocol for two-photon Ca2+ imaging in the auditory cortex of head-fixed behaving mice. By using a custom-made head fixation apparatus and a head-rotated fixation procedure, we achieved two-photon imaging and in combination with targeted cell-attached recordings of auditory cortical neurons in behaving mice. Using synthetic Ca2+ indicators, we recorded the Ca2+ transients at multiple scales, including neuronal populations, single neurons, dendrites and single spines, in auditory cortex during behavior. Furthermore, using genetically encoded Ca2+ indicators (GECIs), we monitored the neuronal dynamics over days throughout the process of associative learning. Therefore, we achieved two-photon functional imaging at multiple scales in auditory cortex of behaving mice, which extends the tool box for investigating the neural basis of audition-related behaviors. PMID:29740289

Field-effect transistor improves electrometer amplifier

NASA Technical Reports Server (NTRS)

Munoz, R.

1964-01-01

An electrometer amplifier uses a field effect transistor to measure currents of low amperage. The circuit, developed as an ac amplifier, is used with an external filter which limits bandwidth to achieve optimum noise performance.

Large-scale complementary macroelectronics using hybrid integration of carbon nanotubes and IGZO thin-film transistors.

PubMed

Chen, Haitian; Cao, Yu; Zhang, Jialu; Zhou, Chongwu

2014-06-13

Carbon nanotubes and metal oxide semiconductors have emerged as important materials for p-type and n-type thin-film transistors, respectively; however, realizing sophisticated macroelectronics operating in complementary mode has been challenging due to the difficulty in making n-type carbon nanotube transistors and p-type metal oxide transistors. Here we report a hybrid integration of p-type carbon nanotube and n-type indium-gallium-zinc-oxide thin-film transistors to achieve large-scale (>1,000 transistors for 501-stage ring oscillators) complementary macroelectronic circuits on both rigid and flexible substrates. This approach of hybrid integration allows us to combine the strength of p-type carbon nanotube and n-type indium-gallium-zinc-oxide thin-film transistors, and offers high device yield and low device variation. Based on this approach, we report the successful demonstration of various logic gates (inverter, NAND and NOR gates), ring oscillators (from 51 stages to 501 stages) and dynamic logic circuits (dynamic inverter, NAND and NOR gates).

Three-terminal graphene single-electron transistor fabricated using feedback-controlled electroburning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Puczkarski, Paweł; Gehring, Pascal, E-mail: pascal.gehring@materials.ox.ac.uk; Lau, Chit S.

2015-09-28

We report room-temperature Coulomb blockade in a single layer graphene three-terminal single-electron transistor fabricated using feedback-controlled electroburning. The small separation between the side gate electrode and the graphene quantum dot results in a gate coupling up to 3 times larger compared to the value found for the back gate electrode. This allows for an effective tuning between the conductive and Coulomb blocked state using a small side gate voltage of about 1 V. The technique can potentially be used in the future to fabricate all-graphene based room temperature single-electron transistors or three terminal single molecule transistors with enhanced gate coupling.

Murine serum glycoprotein gp70 behaves as an acute phase reactant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hara, I.; Izui, S.; Dixon, F.J.

1982-02-01

A single intraperitoneal injection of bacterial lipopolysaccharide (LPS) or its lipid A component induced high levels of glycoprotein, gp70, in sera of several strains of mice within 24 h. This serum gp70 response induced by LPS was independent of the activation of B cells and the presence of T cells. However, serological and immunohistochemical studies demonstrated the production of gp70 by hepatic parenchymal cells and its subsequent release into the circulating blood. The expression of gp70 in the serum was enhanced not only by LPS but also other inducers of acute phase reactants (APR) such as turpentine oil or polyriboinosinic-polyribocytidylicmore » acid. Further, the serum gp70 response was kinetically identical to those of APR. These results strongly suggest that (a) the liver may be the major source for serum gp70, (b) serum gp70 behaves like an APR, (c) its expression may be controlled by a mechanism similar to that for other APR, and (d) this glycoprotein apparently behaves as a normal host constituent and not a product of a viral genome.« less

Application of Transistors in Textiles: Monitoring Water Transportation Behaviour in Fibrous Assemblies

NASA Astrophysics Data System (ADS)

Chatterjee, Arobindo; Singh, Pratibha; Ghosh, Subrata

2017-06-01

Simple semiconductor device has been used for amplifying the analog signals, obtained with the change in electrical resistance in fibrous assembly and converting these amplified copies of signals to digital signals. This paper deals with the application of transistors as amplifier, as well as switch. Different circuit configurations using transistors have been tried for sensing and reciprocating the real time data on suitable display device. It is found that transistors configured as common-emitter amplifiers can precisely sense the liquid at the surface of fibrous assembly at different levels with respect to time.

Inorganic proton conducting electrolyte coupled oxide-based dendritic transistors for synaptic electronics.

PubMed

Wan, Chang Jin; Zhu, Li Qiang; Zhou, Ju Mei; Shi, Yi; Wan, Qing

2014-05-07

Ionic/electronic hybrid devices with synaptic functions are considered to be the essential building blocks for neuromorphic systems and brain-inspired computing. Here, artificial synapses based on indium-zinc-oxide (IZO) transistors gated by nanogranular SiO2 proton-conducting electrolyte films are fabricated on glass substrates. Spike-timing dependent plasticity and paired-pulse facilitation are successfully mimicked in an individual bottom-gate transistor. Most importantly, dynamic logic and dendritic integration established by spatiotemporally correlated spikes are also mimicked in dendritic transistors with two in-plane gates as the presynaptic input terminals.

E-Learning System for Design and Construction of Amplifier Using Transistors

ERIC Educational Resources Information Center

Takemura, Atsushi

2014-01-01

This paper proposes a novel e-Learning system for the comprehensive understanding of electronic circuits with transistors. The proposed e-Learning system allows users to learn a wide range of topics, encompassing circuit theories, design, construction, and measurement. Given the fact that the amplifiers with transistors are an integral part of…

Oxide-based thin film transistors for flexible electronics

NASA Astrophysics Data System (ADS)

He, Yongli; Wang, Xiangyu; Gao, Ya; Hou, Yahui; Wan, Qing

2018-01-01

The continuous progress in thin film materials and devices has greatly promoted the development in the field of flexible electronics. As one of the most common thin film devices, thin film transistors (TFTs) are significant building blocks for flexible platforms. Flexible oxide-based TFTs are well compatible with flexible electronic systems due to low process temperature, high carrier mobility, and good uniformity. The present article is a review of the recent progress and major trends in the field of flexible oxide-based thin film transistors. First, an introduction of flexible electronics and flexible oxide-based thin film transistors is given. Next, we introduce oxide semiconductor materials and various flexible oxide-based TFTs classified by substrate materials including polymer plastics, paper sheets, metal foils, and flexible thin glass. Afterwards, applications of flexible oxide-based TFTs including bendable sensors, memories, circuits, and displays are presented. Finally, we give conclusions and a prospect for possible development trends. Project supported in part by the National Science Foundation for Distinguished Young Scholars of China (No. 61425020), in part by the National Natural Science Foundation of China (No. 11674162).

Ferroelectric Field-Effect Transistor Differential Amplifier Circuit Analysis

NASA Technical Reports Server (NTRS)

Phillips, Thomas A.; MacLeod, Todd C.; Ho, Fat D.

2008-01-01

There has been considerable research investigating the Ferroelectric Field-Effect Transistor (FeFET) in memory circuits. However, very little research has been performed in applying the FeFET to analog circuits. This paper investigates the use of FeFETs in a common analog circuit, the differential amplifier. The two input Metal-Oxide-Semiconductor (MOS) transistors in a general MOS differential amplifier circuit are replaced with FeFETs. Resistors are used in place of the other three MOS transistors. The FeFET model used in the analysis has been previously reported and was based on experimental device data. Because of the FeFET hysteresis, the FeFET differential amplifier has four different operating modes depending on whether the FeFETs are positively or negatively polarized. The FeFET differential amplifier operation in the different modes was analyzed by calculating the amplifier voltage transfer and gain characteristics shown in figures 2 through 5. Comparisons were made between the FeFET differential amplifier and the standard MOS differential amplifier. Possible applications and benefits of the FeFET differential amplifier are discussed.

Lead iodide perovskite light-emitting field-effect transistor

PubMed Central

Chin, Xin Yu; Cortecchia, Daniele; Yin, Jun; Bruno, Annalisa; Soci, Cesare

2015-01-01

Despite the widespread use of solution-processable hybrid organic–inorganic perovskites in photovoltaic and light-emitting applications, determination of their intrinsic charge transport parameters has been elusive due to the variability of film preparation and history-dependent device performance. Here we show that screening effects associated to ionic transport can be effectively eliminated by lowering the operating temperature of methylammonium lead iodide perovskite (CH3NH3PbI3) field-effect transistors. Field-effect carrier mobility is found to increase by almost two orders of magnitude below 200 K, consistent with phonon scattering-limited transport. Under balanced ambipolar carrier injection, gate-dependent electroluminescence is also observed from the transistor channel, with spectra revealing the tetragonal to orthorhombic phase transition. This demonstration of CH3NH3PbI3 light-emitting field-effect transistors provides intrinsic transport parameters to guide materials and solar cell optimization, and will drive the development of new electro-optic device concepts, such as gated light-emitting diodes and lasers operating at room temperature. PMID:26108967

Enhanced vapour sensing using silicon nanowire devices coated with Pt nanoparticle functionalized porous organic frameworks.

PubMed

Cao, Anping; Shan, Meixia; Paltrinieri, Laura; Evers, Wiel H; Chu, Liangyong; Poltorak, Lukasz; Klootwijk, Johan H; Seoane, Beatriz; Gascon, Jorge; Sudhölter, Ernst J R; de Smet, Louis C P M

2018-04-19

Recently various porous organic frameworks (POFs, crystalline or amorphous materials) have been discovered, and used for a wide range of applications, including molecular separations and catalysis. Silicon nanowires (SiNWs) have been extensively studied for diverse applications, including as transistors, solar cells, lithium ion batteries and sensors. Here we demonstrate the functionalization of SiNW surfaces with POFs and explore its effect on the electrical sensing properties of SiNW-based devices. The surface modification by POFs was easily achieved by polycondensation on amine-modified SiNWs. Platinum nanoparticles were formed in these POFs by impregnation with chloroplatinic acid followed by chemical reduction. The final hybrid system showed highly enhanced sensitivity for methanol vapour detection. We envisage that the integration of SiNWs with POF selector layers, loaded with different metal nanoparticles will open up new avenues, not only in chemical and biosensing, but also in separations and catalysis.

High-Performance Quantum Dot Thin-Film Transistors with Environmentally Benign Surface Functionalization and Robust Defect Passivation.

PubMed

Jung, Su Min; Kang, Han Lim; Won, Jong Kook; Kim, JaeHyun; Hwang, ChaHwan; Ahn, KyungHan; Chung, In; Ju, Byeong-Kwon; Kim, Myung-Gil; Park, Sung Kyu

2018-01-31

The recent development of high-performance colloidal quantum dot (QD) thin-film transistors (TFTs) has been achieved with removal of surface ligand, defect passivation, and facile electronic doping. Here, we report on high-performance solution-processed CdSe QD-TFTs with an optimized surface functionalization and robust defect passivation via hydrazine-free metal chalcogenide (MCC) ligands. The underlying mechanism of the ligand effects on CdSe QDs has been studied with hydrazine-free ex situ reaction derived MCC ligands, such as Sn 2 S 6 4- , Sn 2 Se 6 4- , and In 2 Se 4 2- , to allow benign solution-process available. Furthermore, the defect passivation and remote n-type doping effects have been investigated by incorporating indium nanoparticles over the QD layer. Strong electronic coupling and solid defect passivation of QDs could be achieved by introducing electronically active MCC capping and thermal diffusion of the indium nanoparticles, respectively. It is also noteworthy that the diffused indium nanoparticles facilitate charge injection not only inter-QDs but also between source/drain electrodes and the QD semiconductors, significantly reducing contact resistance. With benign organic solvents, the Sn 2 S 6 4- , Sn 2 Se 6 4- , and In 2 Se 4 2- ligand based QD-TFTs exhibited field-effect mobilities exceeding 4.8, 12.0, and 44.2 cm 2 /(V s), respectively. The results reported here imply that the incorporation of MCC ligands and appropriate dopants provide a general route to high-performance, extremely stable solution-processed QD-based electronic devices with marginal toxicity, offering compatibility with standard complementary metal oxide semiconductor processing and large-scale on-chip device applications.

Comparison of conductor and dielectric inks in printed organic complementary transistors

NASA Astrophysics Data System (ADS)

Ng, Tse Nga; Mei, Ping; Whiting, Gregory L.; Schwartz, David E.; Abraham, Biby; Wu, Yiliang; Veres, Janos

2014-10-01

Two types of printable conductor and a bilayer gate dielectric are evaluated for use in all-additive, inkjetprinted complementary OTFTs. The Ag nanoparticle ink based on nonpolar alkyl amine surfactant or stabilizer enables good charge injection into p-channel devices, but this ink also leaves residual stabilizer that modifies the transistor backchannel and shifts the turn-on voltage to negative values. The Ag ink based on polar solvent requires dopant modification to improve charge injection to p-channel devices, but this ink allows the OTFT turn-on voltage to be close to 0 V. The reverse trend is observed for n-channel OTFTs. For gate insulator, a bilayer dielectric is demonstrated that combines the advantages of two types of insulator materials, in which a fluoropolymer reduces dipolar disorder at the semiconductor-dielectric interface, while a high-k PVDF terpolymer dielectric facilitates high gate capacitance. The dielectric is incorporated into an inverter and a three-stage ring oscillator, and the resulting circuits were demonstrated to operate at a supply voltage as low as 2 V, with bias stress levels comparable to circuits with other types of dielectrics.

Burst-type noise mechanisms in bipolar transistors

NASA Astrophysics Data System (ADS)

Wu, X. L.; van der Ziel, A.; Birbas, A. N.; van Rheenen, A. D.

1989-11-01

Two types of burst noise have been observed in silicon bipolar transistors. They can be characterized by the typical frequency dependence of their current fluctuation spectra. Interestingly, observation of the noise signal in the time domain gives two distinctively different pictures of the bistable waveform. Also, amplification of the noise signal yields different sounds when fed to a speaker. One of the noise spectra is the superposition of 1/ƒ noise and a Lorentzian component (burst noise) and the other can be described mathematically as 1/ƒ noise modulated by the burst noise. The classification of those two types of burst noise and the mathematical explanation will lead to a better understanding of the bipolar transistor burst noise itself.

BehavePlus fire modeling system, version 5.0: Design and Features

Treesearch

Faith Ann Heinsch; Patricia L. Andrews

2010-01-01

The BehavePlus fire modeling system is a computer program that is based on mathematical models that describe wildland fire behavior and effects and the fire environment. It is a flexible system that produces tables, graphs, and simple diagrams. It can be used for a host of fire management applications, including projecting the behavior of an ongoing fire, planning...

Cryogenic preamplification of a single-electron-transistor using a silicon-germanium heterojunction-bipolar-transistor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Curry, M. J.; Center for Quantum Information and Control, University of New Mexico, Albuquerque, New Mexico 87131; Sandia National Laboratories, 1515 Eubank Blvd SE, Albuquerque, New Mexico 87123

2015-05-18

We examine a silicon-germanium heterojunction bipolar transistor (HBT) for cryogenic pre-amplification of a single electron transistor (SET). The SET current modulates the base current of the HBT directly. The HBT-SET circuit is immersed in liquid helium, and its frequency response from low frequency to several MHz is measured. The current gain and the noise spectrum with the HBT result in a signal-to-noise-ratio (SNR) that is a factor of 10–100 larger than without the HBT at lower frequencies. The transition frequency defined by SNR = 1 has been extended by as much as a factor of 10 compared to without the HBT amplification.more » The power dissipated by the HBT cryogenic pre-amplifier is approximately 5 nW to 5 μW for the investigated range of operation. The circuit is also operated in a single electron charge read-out configuration in the time-domain as a proof-of-principle demonstration of the amplification approach for single spin read-out.« less

Cryogenic Preamplification of a Single-Electron-Transistor using a Silicon-Germanium Heterojunction-Bipolar-Transistor

DOE PAGES

Curry, Matthew J.; England, Troy Daniel; Bishop, Nathaniel; ...

2015-05-21

We examine a silicon-germanium heterojunction bipolar transistor (HBT) for cryogenic pre-amplification of a single electron transistor (SET). The SET current modulates the base current of the HBT directly. The HBT-SET circuit is immersed in liquid helium, and its frequency response from low frequency to several MHz is measured. The current gain and the noise spectrum with the HBT result in a signal-to-noise-ratio (SNR) that is a factor of 10–100 larger than without the HBT at lower frequencies. Furthermore, the transition frequency defined by SNR = 1 has been extended by as much as a factor of 10 compared to withoutmore » the HBT amplification. The power dissipated by the HBT cryogenic pre-amplifier is approximately 5 nW to 5 μW for the investigated range of operation. We found that the circuit is also operated in a single electron charge read-out configuration in the time-domain as a proof-of-principle demonstration of the amplification approach for single spin read-out.« less

Electrolyte-gated transistors based on conducting polymer nanowire junction arrays.

PubMed

Alam, Maksudul M; Wang, Jun; Guo, Yaoyao; Lee, Stephanie P; Tseng, Hsian-Rong

2005-07-07

In this study, we describe the electrolyte gating and doping effects of transistors based on conducting polymer nanowire electrode junction arrays in buffered aqueous media. Conducting polymer nanowires including polyaniline, polypyrrole, and poly(ethylenedioxythiophene) were investigated. In the presence of a positive gate bias, the device exhibits a large on/off current ratio of 978 for polyaniline nanowire-based transistors; these values vary according to the acidity of the gate medium. We attribute these efficient electrolyte gating and doping effects to the electrochemically fabricated nanostructures of conducting polymer nanowires. This study demonstrates that two-terminal devices can be easily converted into three-terminal transistors by simply immersing the device into an electrolyte solution along with a gate electrode. Here, the field-induced modulation can be applied for signal amplification to enhance the device performance.

High-performance radio frequency transistors based on diameter-separated semiconducting carbon nanotubes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao, Yu; Che, Yuchi; Zhou, Chongwu, E-mail: chongwuz@usc.edu

In this paper, we report the high-performance radio-frequency transistors based on the single-walled semiconducting carbon nanotubes with a refined average diameter of ∼1.6 nm. These diameter-separated carbon nanotube transistors show excellent transconductance of 55 μS/μm and desirable drain current saturation with an output resistance of ∼100 KΩ μm. An exceptional radio-frequency performance is also achieved with current gain and power gain cut-off frequencies of 23 GHz and 20 GHz (extrinsic) and 65 GHz and 35 GHz (intrinsic), respectively. These radio-frequency metrics are among the highest reported for the carbon nanotube thin-film transistors. This study provides demonstration of radio frequency transistors based on carbon nanotubes with tailoredmore » diameter distributions, which will guide the future application of carbon nanotubes in radio-frequency electronics.« less

Unipolar n-Type Black Phosphorus Transistors with Low Work Function Contacts.

PubMed

Wang, Ching-Hua; Incorvia, Jean Anne C; McClellan, Connor J; Yu, Andrew C; Mleczko, Michal J; Pop, Eric; Wong, H-S Philip

2018-05-09

Black phosphorus (BP) is a promising two-dimensional (2D) material for nanoscale transistors, due to its expected higher mobility than other 2D semiconductors. While most studies have reported ambipolar BP with a stronger p-type transport, it is important to fabricate both unipolar p- and n-type transistors for low-power digital circuits. Here, we report unipolar n-type BP transistors with low work function Sc and Er contacts, demonstrating a record high n-type current of 200 μA/μm in 6.5 nm thick BP. Intriguingly, the electrical transport of the as-fabricated, capped devices changes from ambipolar to n-type unipolar behavior after a month at room temperature. Transmission electron microscopy analysis of the contact cross-section reveals an intermixing layer consisting of partly oxidized metal at the interface. This intermixing layer results in a low n-type Schottky barrier between Sc and BP, leading to the unipolar behavior of the BP transistor. This unipolar transport with a suppressed p-type current is favorable for digital logic circuits to ensure a lower off-power consumption.

Analysing black phosphorus transistors using an analytic Schottky barrier MOSFET model

PubMed Central

Penumatcha, Ashish V.; Salazar, Ramon B.; Appenzeller, Joerg

2015-01-01

Owing to the difficulties associated with substitutional doping of low-dimensional nanomaterials, most field-effect transistors built from carbon nanotubes, two-dimensional crystals and other low-dimensional channels are Schottky barrier MOSFETs (metal-oxide-semiconductor field-effect transistors). The transmission through a Schottky barrier-MOSFET is dominated by the gate-dependent transmission through the Schottky barriers at the metal-to-channel interfaces. This makes the use of conventional transistor models highly inappropriate and has lead researchers in the past frequently to extract incorrect intrinsic properties, for example, mobility, for many novel nanomaterials. Here we propose a simple modelling approach to quantitatively describe the transfer characteristics of Schottky barrier-MOSFETs from ultra-thin body materials accurately in the device off-state. In particular, after validating the model through the analysis of a set of ultra-thin silicon field-effect transistor data, we have successfully applied our approach to extract Schottky barrier heights for electrons and holes in black phosphorus devices for a large range of body thicknesses. PMID:26563458

Pseudo-diode based on protonic/electronic hybrid oxide transistor

NASA Astrophysics Data System (ADS)

Fu, Yang Ming; Liu, Yang Hui; Zhu, Li Qiang; Xiao, Hui; Song, An Ran

2018-01-01

Current rectification behavior has been proved to be essential in modern electronics. Here, a pseudo-diode is proposed based on protonic/electronic hybrid indium-gallium-zinc oxide electric-double-layer (EDL) transistor. The oxide EDL transistors are fabricated by using phosphorous silicate glass (PSG) based proton conducting electrolyte as gate dielectric. A diode operation mode is established on the transistor, originating from field configurable proton fluxes within the PSG electrolyte. Current rectification ratios have been modulated to values ranged between ˜4 and ˜50 000 with gate electrode biased at voltages ranged between -0.7 V and 0.1 V. Interestingly, the proposed pseudo-diode also exhibits field reconfigurable threshold voltages. When the gate is biased at -0.5 V and 0.3 V, threshold voltages are set to ˜-1.3 V and -0.55 V, respectively. The proposed pseudo-diode may find potential applications in brain-inspired platforms and low-power portable systems.

Molecularly stabilised ultrasmall gold nanoparticles: synthesis, characterization and bioactivity

NASA Astrophysics Data System (ADS)

Leifert, Annika; Pan-Bartnek, Yu; Simon, Ulrich; Jahnen-Dechent, Willi

2013-06-01

Gold nanoparticles (AuNPs) are widely used as contrast agents in electron microscopy as well as for diagnostic tests. Due to their unique optical and electrical properties and their small size, there is also a growing field of potential applications in medical fields of imaging and therapy, for example as drug carriers or as active compounds in thermotherapy. Besides their intrinsic optical properties, facile surface decoration with (bio)functional ligands renders AuNPs ideally suited for many industrial and medical applications. However, novel AuNPs may have toxicological profiles differing from bulk and therefore a thorough analysis of the quantitative structure-activity relationship (QSAR) is required. Several mechanisms are proposed that cause adverse effects of nanoparticles in biological systems. Catalytic generation of reactive species due to the large and chemically active surface area of nanomaterials is well established. Because nanoparticles approach the size of biological molecules and subcellular structures, they may overcome natural barriers by active or passive uptake. Ultrasmall AuNPs with sizes of 2 nm or less may even behave as molecular ligands. These types of potential interactions would imply a size and ligand-dependent behaviour of any nanomaterial towards biological systems. Thus, to fully understand their QSAR, AuNPs bioactivity should be analysed in biological systems of increasing complexity ranging from cell culture to whole animal studies.

Controlling the mode of operation of organic transistors through side-chain engineering.

PubMed

Giovannitti, Alexander; Sbircea, Dan-Tiberiu; Inal, Sahika; Nielsen, Christian B; Bandiello, Enrico; Hanifi, David A; Sessolo, Michele; Malliaras, George G; McCulloch, Iain; Rivnay, Jonathan

2016-10-25

Electrolyte-gated organic transistors offer low bias operation facilitated by direct contact of the transistor channel with an electrolyte. Their operation mode is generally defined by the dimensionality of charge transport, where a field-effect transistor allows for electrostatic charge accumulation at the electrolyte/semiconductor interface, whereas an organic electrochemical transistor (OECT) facilitates penetration of ions into the bulk of the channel, considered a slow process, leading to volumetric doping and electronic transport. Conducting polymer OECTs allow for fast switching and high currents through incorporation of excess, hygroscopic ionic phases, but operate in depletion mode. Here, we show that the use of glycolated side chains on a thiophene backbone can result in accumulation mode OECTs with high currents, transconductance, and sharp subthreshold switching, while maintaining fast switching speeds. Compared with alkylated analogs of the same backbone, the triethylene glycol side chains shift the mode of operation of aqueous electrolyte-gated transistors from interfacial to bulk doping/transport and show complete and reversible electrochromism and high volumetric capacitance at low operating biases. We propose that the glycol side chains facilitate hydration and ion penetration, without compromising electronic mobility, and suggest that this synthetic approach can be used to guide the design of organic mixed conductors.

Controlling the mode of operation of organic transistors through side-chain engineering

PubMed Central

Giovannitti, Alexander; Sbircea, Dan-Tiberiu; Inal, Sahika; Nielsen, Christian B.; Bandiello, Enrico; Hanifi, David A.; Sessolo, Michele; Malliaras, George G.; McCulloch, Iain; Rivnay, Jonathan

2016-01-01

Electrolyte-gated organic transistors offer low bias operation facilitated by direct contact of the transistor channel with an electrolyte. Their operation mode is generally defined by the dimensionality of charge transport, where a field-effect transistor allows for electrostatic charge accumulation at the electrolyte/semiconductor interface, whereas an organic electrochemical transistor (OECT) facilitates penetration of ions into the bulk of the channel, considered a slow process, leading to volumetric doping and electronic transport. Conducting polymer OECTs allow for fast switching and high currents through incorporation of excess, hygroscopic ionic phases, but operate in depletion mode. Here, we show that the use of glycolated side chains on a thiophene backbone can result in accumulation mode OECTs with high currents, transconductance, and sharp subthreshold switching, while maintaining fast switching speeds. Compared with alkylated analogs of the same backbone, the triethylene glycol side chains shift the mode of operation of aqueous electrolyte-gated transistors from interfacial to bulk doping/transport and show complete and reversible electrochromism and high volumetric capacitance at low operating biases. We propose that the glycol side chains facilitate hydration and ion penetration, without compromising electronic mobility, and suggest that this synthetic approach can be used to guide the design of organic mixed conductors. PMID:27790983

Controllable film densification and interface flatness for high-performance amorphous indium oxide based thin film transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ou-Yang, Wei, E-mail: OUYANG.Wei@nims.go.jp, E-mail: TSUKAGOSHI.Kazuhito@nims.go.jp; Mitoma, Nobuhiko; Kizu, Takio

2014-10-20

To avoid the problem of air sensitive and wet-etched Zn and/or Ga contained amorphous oxide transistors, we propose an alternative amorphous semiconductor of indium silicon tungsten oxide as the channel material for thin film transistors. In this study, we employ the material to reveal the relation between the active thin film and the transistor performance with aid of x-ray reflectivity study. By adjusting the pre-annealing temperature, we find that the film densification and interface flatness between the film and gate insulator are crucial for achieving controllable high-performance transistors. The material and findings in the study are believed helpful for realizingmore » controllable high-performance stable transistors.« less

REGENERATIVE TRANSISTOR AMPLIFIER

DOEpatents

Kabell, L.J.

1958-11-25

Electrical circults for use in computers and the like are described. particularly a regenerative bistable transistor amplifler which is iurned on by a clock signal when an information signal permits and is turned off by the clock signal. The amplifier porforms the above function with reduced power requirements for the clock signal and circuit operation. The power requirements are reduced in one way by employing transformer coupling which increases the collector circuit efficiency by eliminating the loss of power in the collector load resistor.

Collaborating with Parents for Early School Success: The Achieving-Behaving-Caring Program

ERIC Educational Resources Information Center

McConaughy, Stephanie H.; Kay, Pam; Welkowitz, Julie A.; Hewitt, Kim; Fitzgerald, Martha D.

2007-01-01

The Achieving-Behaving-Caring (ABC) Program is an evidence-based approach to addressing the needs of elementary students at risk for emotional and behavioral difficulties and promoting successful home-school collaboration. This practical guide demonstrates how classroom teachers and parents can work together to boost individual children's…

Ambipolar pentacene field-effect transistor with double-layer organic insulator

NASA Astrophysics Data System (ADS)

Kwak, Jeong-Hun; Baek, Heume-Il; Lee, Changhee

2006-08-01

Ambipolar conduction in organic field-effect transistor is very important feature to achieve organic CMOS circuitry. We fabricated an ambipolar pentacene field-effect transistors consisted of gold source-drain electrodes and double-layered PMMA (Polymethylmethacrylate) / PVA (Polyvinyl Alcohol) organic insulator on the ITO(Indium-tin-oxide)-patterned glass substrate. These top-contact geometry field-effect transistors were fabricated in the vacuum of 10 -6 Torr and minimally exposed to atmosphere before its measurement and characterized in the vacuum condition. Our device showed reasonable p-type characteristics of field-effect hole mobility of 0.2-0.9 cm2/Vs and the current ON/OFF ratio of about 10 6 compared to prior reports with similar configurations. For the n-type characteristics, field-effect electron mobility of 0.004-0.008 cm2/Vs and the current ON/OFF ratio of about 10 3 were measured, which is relatively high performance for the n-type conduction of pentacene field-effect transistors. We attributed these ambipolar properties mainly to the hydroxyl-free PMMA insulator interface with the pentacene active layer. In addition, an increased insulator capacitance due to double-layer insulator structure with high-k PVA layer also helped us to observe relatively good n-type characteristics.

Light-Stimulated Synaptic Devices Utilizing Interfacial Effect of Organic Field-Effect Transistors.

PubMed

Dai, Shilei; Wu, Xiaohan; Liu, Dapeng; Chu, Yingli; Wang, Kai; Yang, Ben; Huang, Jia

2018-06-14

Synaptic transistors stimulated by light waves or photons may offer advantages to the devices, such as wide bandwidth, ultrafast signal transmission, and robustness. However, previously reported light-stimulated synaptic devices generally require special photoelectric properties from the semiconductors and sophisticated device's architectures. In this work, a simple and effective strategy for fabricating light-stimulated synaptic transistors is provided by utilizing interface charge trapping effect of organic field-effect transistors (OFETs). Significantly, our devices exhibited highly synapselike behaviors, such as excitatory postsynaptic current (EPSC) and pair-pulse facilitation (PPF), and presented memory and learning ability. The EPSC decay, PPF curves, and forgetting behavior can be well expressed by mathematical equations for synaptic devices, indicating that interfacial charge trapping effect of OFETs can be utilized as a reliable strategy to realize organic light-stimulated synapses. Therefore, this work provides a simple and effective strategy for fabricating light-stimulated synaptic transistors with both memory and learning ability, which enlightens a new direction for developing neuromorphic devices.

Charge transport and trapping in organic field effect transistors exposed to polar analytes

NASA Astrophysics Data System (ADS)

Duarte, Davianne; Sharma, Deepak; Cobb, Brian; Dodabalapur, Ananth

2011-03-01

Pentacene based organic thin-film transistors were used to study the effects of polar analytes on charge transport and trapping behavior during vapor sensing. Three sets of devices with differing morphology and mobility (0.001-0.5 cm2/V s) were employed. All devices show enhanced trapping upon exposure to analyte molecules. The organic field effect transistors with different mobilities also provide evidence for morphology dependent partition coefficients. This study helps provide a physical basis for many reports on organic transistor based sensor response.

Polarization induced doped transistor

DOEpatents

Xing, Huili; Jena, Debdeep; Nomoto, Kazuki; Song, Bo; Zhu, Mingda; Hu, Zongyang

2016-06-07

A nitride-based field effect transistor (FET) comprises a compositionally graded and polarization induced doped p-layer underlying at least one gate contact and a compositionally graded and doped n-channel underlying a source contact. The n-channel is converted from the p-layer to the n-channel by ion implantation, a buffer underlies the doped p-layer and the n-channel, and a drain underlies the buffer.

Quantum engineering of transistors based on 2D materials heterostructures

NASA Astrophysics Data System (ADS)

Iannaccone, Giuseppe; Bonaccorso, Francesco; Colombo, Luigi; Fiori, Gianluca

2018-03-01

Quantum engineering entails atom-by-atom design and fabrication of electronic devices. This innovative technology that unifies materials science and device engineering has been fostered by the recent progress in the fabrication of vertical and lateral heterostructures of two-dimensional materials and by the assessment of the technology potential via computational nanotechnology. But how close are we to the possibility of the practical realization of next-generation atomically thin transistors? In this Perspective, we analyse the outlook and the challenges of quantum-engineered transistors using heterostructures of two-dimensional materials against the benchmark of silicon technology and its foreseeable evolution in terms of potential performance and manufacturability. Transistors based on lateral heterostructures emerge as the most promising option from a performance point of view, even if heterostructure formation and control are in the initial technology development stage.

Carbon Nanotube Thin Film Transistors for Flat Panel Display Application.

PubMed

Liang, Xuelei; Xia, Jiye; Dong, Guodong; Tian, Boyuan; Peng, Lianmao

2016-12-01

Carbon nanotubes (CNTs) are promising materials for both high performance transistors for high speed computing and thin film transistors for macroelectronics, which can provide more functions at low cost. Among macroelectronics applications, carbon nanotube thin film transistors (CNT-TFT) are expected to be used soon for backplanes in flat panel displays (FPDs) due to their superior performance. In this paper, we review the challenges of CNT-TFT technology for FPD applications. The device performance of state-of-the-art CNT-TFTs are compared with the requirements of TFTs for FPDs. Compatibility of the fabrication processes of CNT-TFTs and current TFT technologies are critically examined. Though CNT-TFT technology is not yet ready for backplane production line of FPDs, the challenges can be overcome by close collaboration between research institutes and FPD manufacturers in the short term.

Quantum engineering of transistors based on 2D materials heterostructures.

PubMed

Iannaccone, Giuseppe; Bonaccorso, Francesco; Colombo, Luigi; Fiori, Gianluca

2018-03-01

Quantum engineering entails atom-by-atom design and fabrication of electronic devices. This innovative technology that unifies materials science and device engineering has been fostered by the recent progress in the fabrication of vertical and lateral heterostructures of two-dimensional materials and by the assessment of the technology potential via computational nanotechnology. But how close are we to the possibility of the practical realization of next-generation atomically thin transistors? In this Perspective, we analyse the outlook and the challenges of quantum-engineered transistors using heterostructures of two-dimensional materials against the benchmark of silicon technology and its foreseeable evolution in terms of potential performance and manufacturability. Transistors based on lateral heterostructures emerge as the most promising option from a performance point of view, even if heterostructure formation and control are in the initial technology development stage.

Variable temperature performance of a fully screen printed transistor switch

NASA Astrophysics Data System (ADS)

Zambou, Serges; Magunje, Batsirai; Rhyme, Setshedi; Walton, Stanley D.; Idowu, M. Florence; Unuigbe, David; Britton, David T.; Härting, Margit

2016-12-01

This article reports on the variable temperature performance of a flexible printed transistor which works as a current driven switch. In this work, electronic ink is formulated from nanostructured silicon produced by milling polycrystalline silicon. The study of the silicon active layer shows that its conductivity is based on thermal activation of carriers, and could be used as active layers in active devices. We further report on the transistors switching operation and their electrical performance under variable temperature. The reliability of the transistors at constant current bias was also investigated. Analysis of the electrical transfer characteristics from 340 to 10 K showed that the printed devices' current ON/OFF ratio increases as temperature decreases making it a better switch at lower temperatures. A constant current bias on a terminal for up to six hours shows extraordinary stability in electrical performance of the device.

Carbon Based Transistors and Nanoelectronic Devices

NASA Astrophysics Data System (ADS)

Rouhi, Nima

Carbon based materials (carbon nanotube and graphene) has been extensively researched during the past decade as one of the promising materials to be used in high performance device technology. In long term it is thought that they may replace digital and/or analog electronic devices, due to their size, near-ballistic transport, and high stability. However, a more realistic point of insertion into market may be the printed nanoelectronic circuits and sensors. These applications include printed circuits for flexible electronics and displays, large-scale bendable electrical contacts, bio-membranes and bio sensors, RFID tags, etc. In order to obtain high performance thin film transistors (as the basic building block of electronic circuits) one should be able to manufacture dense arrays of all semiconducting nanotubes. Besides, graphene synthesize and transfer technology is in its infancy and there is plenty of room to improve the current techniques. To realize the performance of nanotube and graphene films in such systems, we need to economically fabricate large-scale devices based on these materials. Following that the performance control over such devices should also be considered for future design variations for broad range of applications. Here we have first investigated carbon nanotube ink as the base material for our devices. The primary ink used consisted of both metallic and semiconducting nanotubes which resulted in networks suitable for moderate-resistivity electrical connections (such as interconnects) and rfmatching circuits. Next, purified all-semiconducting nanotube ink was used to fabricate waferscale, high performance (high mobility, and high on/off ratio) thin film transistors for printed electronic applications. The parameters affecting device performance were studied in detail to establish a roadmap for the future of purified nanotube ink printed thin film transistors. The trade of between mobility and on/off ratio of such devices was studied and the

JAN transistor and diode characterization test program

NASA Technical Reports Server (NTRS)

Takeda, H.

1977-01-01

A statistical summary of electrical characterization was performed on JAN diodes and transistors. Parameters are presented with test conditions, mean, standard deviation, lowest reading, 10% point, 90% point and highest reading.

Interfacial functionalization and engineering of nanoparticles

NASA Astrophysics Data System (ADS)

Song, Yang

nanoparticles in the formation of functional nanocomposites. Part of the dissertation research was also devoted to graphene quantum dots (GQDs)-supported platinum (Pt/G) nanoparticles and their electrocatalytic activity in oxygen reduction reaction. These Pt/G nanocomposites were prepared by a hydrothermal procedure at controlled temperatures. Spectroscopic measurements based on FTIR, Raman and XPS confirmed the formation of various oxygenated structural defects on GQDs and the variation of their concentrations with the hydrothermal conditions. Interestingly, electrocatalytic activity of GQD/Pt composites exhibited a volcano-shaped variation with the GQD structural defects, with the best identified as the samples prepared at 160 °C for 6 h where the mass activity was found to meet the DOE target for 2015. This remarkable performance was accounted for by the deliberate manipulation of the adsorption of oxygen and reaction intermediates on platinum by the GQD structural defects through partial charge transfer. The strategy presented herein may offer a new paradigm in the design and engineering of nanoparticle catalysts for fuel cell electrochemistry. In addition, studies were also carried out to study intervalence charge transfer between ferrocenyl moieties bonded on carbon nanoparticle surfaces by diazonium reaction. Electrochemical studies exhibited two pairs of voltammetric waves with a difference of their formal potentials at about 78 mV, suggesting nanoparticle-mediated intraparticle charge delocalization at mixed valence as a result of the strong core-ligand covalent bonds and the conductive sp 2 carbon matrix of the graphitic cores. Consistent behaviors were observed in near-infrared measurements, indicating that the particles behaved analogously to a Class I/II mixed-valence compound.

Multifunctional Self-Assembled Monolayers for Organic Field-Effect Transistors

NASA Astrophysics Data System (ADS)

Cernetic, Nathan

Organic field effect transistors (OFETs) have the potential to reach commercialization for a wide variety of applications such as active matrix display circuitry, chemical and biological sensing, radio-frequency identification devices and flexible electronics. In order to be commercially competitive with already at-market amorphous silicon devices, OFETs need to approach similar performance levels. Significant progress has been made in developing high performance organic semiconductors and dielectric materials. Additionally, a common route to improve the performance metric of OFETs is via interface modification at the critical dielectric/semiconductor and electrode/semiconductor interface which often play a significant role in charge transport properties. These metal oxide interfaces are typically modified with rationally designed multifunctional self-assembled monolayers. As means toward improving the performance metrics of OFETs, rationally designed multifunctional self-assembled monolayers are used to explore the relationship between surface energy, SAM order, and SAM dipole on OFET performance. The studies presented within are (1) development of a multifunctional SAM capable of simultaneously modifying dielectric and metal surface while maintaining compatibility with solution processed techniques (2) exploration of the relationship between SAM dipole and anchor group on graphene transistors, and (3) development of self-assembled monolayer field-effect transistor in which the traditional thick organic semiconductor is replaced by a rationally designed self-assembled monolayer semiconductor. The findings presented within represent advancement in the understanding of the influence of self-assembled monolayers on OFETs as well as progress towards rationally designed monolayer transistors.

Optomechanical transistor with mechanical gain

NASA Astrophysics Data System (ADS)

Zhang, X. Z.; Tian, Lin; Li, Yong

2018-04-01

We study an optomechanical transistor, where an input field can be transferred and amplified unidirectionally in a cyclic three-mode optomechanical system. In this system, the mechanical resonator is coupled simultaneously to two cavity modes. We show that it only requires a finite mechanical gain to achieve the nonreciprocal amplification. Here the nonreciprocity is caused by the phase difference between the linearized optomechanical couplings that breaks the time-reversal symmetry of this system. The amplification arises from the mechanical gain, which provides an effective phonon bath that pumps the mechanical mode coherently. This effect is analogous to the stimulated emission of atoms, where the probe field can be amplified when its frequency is in resonance with that of the anti-Stokes transition. We show that by choosing optimal parameters, this optomechanical transistor can reach perfect unidirectionality accompanied with strong amplification. In addition, the presence of the mechanical gain can result in ultralong delay in the phase of the probe field, which provides an alternative to controlling light transport in optomechanical systems.

Nanogap Electrodes towards Solid State Single-Molecule Transistors.

PubMed

Cui, Ajuan; Dong, Huanli; Hu, Wenping

2015-12-01

With the establishment of complementary metal-oxide-semiconductor (CMOS)-based integrated circuit technology, it has become more difficult to follow Moore's law to further downscale the size of electronic components. Devices based on various nanostructures were constructed to continue the trend in the minimization of electronics, and molecular devices are among the most promising candidates. Compared with other candidates, molecular devices show unique superiorities, and intensive studies on molecular devices have been carried out both experimentally and theoretically at the present time. Compared to two-terminal molecular devices, three-terminal devices, namely single-molecule transistors, show unique advantages both in fundamental research and application and are considered to be an essential part of integrated circuits based on molecular devices. However, it is very difficult to construct them using the traditional microfabrication techniques directly, thus new fabrication strategies are developed. This review aims to provide an exclusive way of manufacturing solid state gated nanogap electrodes, the foundation of constructing transistors of single or a few molecules. Such single-molecule transistors have the potential to be used to build integrated circuits. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Voltage controlled spintronic devices for logic applications

DOEpatents

You, Chun-Yeol; Bader, Samuel D.

2001-01-01

A reprogrammable logic gate comprising first and second voltage-controlled rotation transistors. Each transistor comprises three ferromagnetic layers with a spacer and insulating layer between the first and second ferromagnetic layers and an additional insulating layer between the second and third ferromagnetic layers. The third ferromagnetic layer of each transistor is connected to each other, and a constant external voltage source is applied to the second ferromagnetic layer of the first transistor. As input voltages are applied to the first ferromagnetic layer of each transistor, the relative directions of magnetization of the ferromagnetic layers and the magnitude of the external voltage determines the output voltage of the gate. By altering these parameters, the logic gate is capable of behaving as AND, OR, NAND, or NOR gates.

Gallium nitride junction field-effect transistor

DOEpatents

Zolper, John C.; Shul, Randy J.

1999-01-01

An all-ion implanted gallium-nitride (GaN) junction field-effect transistor (JFET) and method of making the same. Also disclosed are various ion implants, both n- and p-type, together with or without phosphorous co-implantation, in selected III-V semiconductor materials.

Gate Tunable Transport in Graphene/MoS₂/(Cr/Au) Vertical Field-Effect Transistors.

PubMed

Nazir, Ghazanfar; Khan, Muhammad Farooq; Aftab, Sikandar; Afzal, Amir Muhammad; Dastgeer, Ghulam; Rehman, Malik Abdul; Seo, Yongho; Eom, Jonghwa

2017-12-28

Two-dimensional materials based vertical field-effect transistors have been widely studied due to their useful applications in industry. In the present study, we fabricate graphene/MoS₂/(Cr/Au) vertical transistor based on the mechanical exfoliation and dry transfer method. Since the bottom electrode was made of monolayer graphene (Gr), the electrical transport in our Gr/MoS₂/(Cr/Au) vertical transistors can be significantly modified by using back-gate voltage. Schottky barrier height at the interface between Gr and MoS₂ can be modified by back-gate voltage and the current bias. Vertical resistance (R vert ) of a Gr/MoS₂/(Cr/Au) transistor is compared with planar resistance (R planar ) of a conventional lateral MoS₂ field-effect transistor. We have also studied electrical properties for various thicknesses of MoS₂ channels in both vertical and lateral transistors. As the thickness of MoS₂ increases, R vert increases, but R planar decreases. The increase of R vert in the thicker MoS₂ film is attributed to the interlayer resistance in the vertical direction. However, R planar shows a lower value for a thicker MoS₂ film because of an excess of charge carriers available in upper layers connected directly to source/drain contacts that limits the conduction through layers closed to source/drain electrodes. Hence, interlayer resistance associated with these layers contributes to planer resistance in contrast to vertical devices in which all layers contribute interlayer resistance.

Demonstration and properties of a planar heterojunction bipolar transistor with lateral current flow

NASA Astrophysics Data System (ADS)

Thornton, Robert L.; Mosby, William J.; Chung, Harlan F.

1989-10-01

The authors present fabrication techniques and device performance for a novel transistor structure, the lateral heterojunction bipolar transistor. The lateral heterojunctions are formed by impurity-induced disordering of a GaAs base layer sandwiched between two AlGaAs layers. These transistor structures exhibit current gains of 14 for base widths of 0.74 micron. Transistor action in this device occurs parallel to the surface of the device structure. The active base region of the structure is completely submerged, resulting in a reduction of surface recombination as a mechanism for gain reduction in the device. Impurity-induced disordering is used to widen the bandgap of the alloy in the emitter and collector, resulting in an improvement of the emitter injection efficiency. Since the device is based entirely on a surface diffusion process, the device is completely planar and has no steps involving etching of the III-V alloy material. These advantages lead this device to be considered as a candidate for optoelectronic integration applications. The transistor device functions as a buried heterostructure laser, with a threshold current as low as 6 mA for a 1.4-micron stripe.

Liquid-Solid Dual-Gate Organic Transistors with Tunable Threshold Voltage for Cell Sensing.

PubMed

Zhang, Yu; Li, Jun; Li, Rui; Sbircea, Dan-Tiberiu; Giovannitti, Alexander; Xu, Junling; Xu, Huihua; Zhou, Guodong; Bian, Liming; McCulloch, Iain; Zhao, Ni

2017-11-08

Liquid electrolyte-gated organic field effect transistors and organic electrochemical transistors have recently emerged as powerful technology platforms for sensing and simulation of living cells and organisms. For such applications, the transistors are operated at a gate voltage around or below 0.3 V because prolonged application of a higher voltage bias can lead to membrane rupturing and cell death. This constraint often prevents the operation of the transistors at their maximum transconductance or most sensitive regime. Here, we exploit a solid-liquid dual-gate organic transistor structure, where the threshold voltage of the liquid-gated conduction channel is controlled by an additional gate that is separated from the channel by a metal-oxide gate dielectric. With this design, the threshold voltage of the "sensing channel" can be linearly tuned in a voltage window exceeding 0.4 V. We have demonstrated that the dual-gate structure enables a much better sensor response to the detachment of human mesenchymal stem cells. In general, the capability of tuning the optimal sensing bias will not only improve the device performance but also broaden the material selection for cell-based organic bioelectronics.

Subtractive Plasma-Assisted-Etch Process for Developing High Performance Nanocrystalline Zinc-Oxide Thin-Film-Transistors

DTIC Science & Technology

2015-03-26

THIN - FILM - TRANSISTORS THESIS Thomas M. Donigan, First Lieutenant, USAF AFIT-ENG-MS-15-M-027 DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY AIR...DEVELOPING HIGH PERFORMANCE NANOCRYSTALLINE ZINC-OXIDE THIN - FILM - TRANSISTORS THESIS Presented to the Faculty Department of Electrical and...15-M-027 SUBTRACTIVE PLASMA-ASSISTED-ETCH PROCESS FOR DEVELOPING HIGH PERFORMANCE NANOCRYSTALLINE ZINC-OXIDE THIN - FILM - TRANSISTORS

Reconfigurable quadruple quantum dots in a silicon nanowire transistor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Betz, A. C., E-mail: ab2106@cam.ac.uk; Broström, M.; Gonzalez-Zalba, M. F.

2016-05-16

We present a reconfigurable metal-oxide-semiconductor multi-gate transistor that can host a quadruple quantum dot in silicon. The device consists of an industrial quadruple-gate silicon nanowire field-effect transistor. Exploiting the corner effect, we study the versatility of the structure in the single quantum dot and the serial double quantum dot regimes and extract the relevant capacitance parameters. We address the fabrication variability of the quadruple-gate approach which, paired with improved silicon fabrication techniques, makes the corner state quantum dot approach a promising candidate for a scalable quantum information architecture.

Neural circuit activity in freely behaving zebrafish (Danio rerio).

PubMed

Issa, Fadi A; O'Brien, Georgeann; Kettunen, Petronella; Sagasti, Alvaro; Glanzman, David L; Papazian, Diane M

2011-03-15

Examining neuronal network activity in freely behaving animals is advantageous for probing the function of the vertebrate central nervous system. Here, we describe a simple, robust technique for monitoring the activity of neural circuits in unfettered, freely behaving zebrafish (Danio rerio). Zebrafish respond to unexpected tactile stimuli with short- or long-latency escape behaviors, which are mediated by distinct neural circuits. Using dipole electrodes immersed in the aquarium, we measured electric field potentials generated in muscle during short- and long-latency escapes. We found that activation of the underlying neural circuits produced unique field potential signatures that are easily recognized and can be repeatedly monitored. In conjunction with behavioral analysis, we used this technique to track changes in the pattern of circuit activation during the first week of development in animals whose trigeminal sensory neurons were unilaterally ablated. One day post-ablation, the frequency of short- and long-latency responses was significantly lower on the ablated side than on the intact side. Three days post-ablation, a significant fraction of escapes evoked by stimuli on the ablated side was improperly executed, with the animal turning towards rather than away from the stimulus. However, the overall response rate remained low. Seven days post-ablation, the frequency of escapes increased dramatically and the percentage of improperly executed escapes declined. Our results demonstrate that trigeminal ablation results in rapid reconfiguration of the escape circuitry, with reinnervation by new sensory neurons and adaptive changes in behavior. This technique is valuable for probing the activity, development, plasticity and regeneration of neural circuits under natural conditions.

Neural circuit activity in freely behaving zebrafish (Danio rerio)

PubMed Central

Issa, Fadi A.; O'Brien, Georgeann; Kettunen, Petronella; Sagasti, Alvaro; Glanzman, David L.; Papazian, Diane M.

2011-01-01

Examining neuronal network activity in freely behaving animals is advantageous for probing the function of the vertebrate central nervous system. Here, we describe a simple, robust technique for monitoring the activity of neural circuits in unfettered, freely behaving zebrafish (Danio rerio). Zebrafish respond to unexpected tactile stimuli with short- or long-latency escape behaviors, which are mediated by distinct neural circuits. Using dipole electrodes immersed in the aquarium, we measured electric field potentials generated in muscle during short- and long-latency escapes. We found that activation of the underlying neural circuits produced unique field potential signatures that are easily recognized and can be repeatedly monitored. In conjunction with behavioral analysis, we used this technique to track changes in the pattern of circuit activation during the first week of development in animals whose trigeminal sensory neurons were unilaterally ablated. One day post-ablation, the frequency of short- and long-latency responses was significantly lower on the ablated side than on the intact side. Three days post-ablation, a significant fraction of escapes evoked by stimuli on the ablated side was improperly executed, with the animal turning towards rather than away from the stimulus. However, the overall response rate remained low. Seven days post-ablation, the frequency of escapes increased dramatically and the percentage of improperly executed escapes declined. Our results demonstrate that trigeminal ablation results in rapid reconfiguration of the escape circuitry, with reinnervation by new sensory neurons and adaptive changes in behavior. This technique is valuable for probing the activity, development, plasticity and regeneration of neural circuits under natural conditions. PMID:21346131

A hydrogel capsule as gate dielectric in flexible organic field-effect transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dumitru, L. M.; Manoli, K.; Magliulo, M.

2015-01-01

A jellified alginate based capsule serves as biocompatible and biodegradable electrolyte system to gate an organic field-effect transistor fabricated on a flexible substrate. Such a system allows operating thiophene based polymer transistors below 0.5 V through an electrical double layer formed across an ion-permeable polymeric electrolyte. Moreover, biological macro-molecules such as glucose-oxidase and streptavidin can enter into the gating capsules that serve also as delivery system. An enzymatic bio-reaction is shown to take place in the capsule and preliminary results on the measurement of the electronic responses promise for low-cost, low-power, flexible electronic bio-sensing applications using capsule-gated organic field-effect transistors.

Nonlocal optical effects on the Goos-Hänchen shift at an interface of a composite material of metallic nanoparticles.

PubMed

Huang, J H; Leung, P T

2013-07-01

We present a theoretical study on the nonlocal optical effects on the Goos-Hänchen (GH) shift of reflected light from a composite material of metallic nanoparticles (MNPs). Using different nonlocal effective medium models, it is observed that such effects can be significant for small MNP of sizes down to a few nanometers. For small metallic volume fractions, the composite behaves like dielectric and the nonlocal effects lead to significant different Brewster angles, at which large negative GH shifts take place. For larger volume fractions or shorter wavelengths, the composite behaves more like metals and the nonlocal effects also lead to different Brewster angles but at values close to grazing incidence. These results will have significant implications in the application of different effective medium models for the characterization of these nanometallic composites when the MNPs are down to a few nanometers in size.

A quantum optical transistor with a single quantum dot in a photonic crystal nanocavity.

PubMed

Li, Jin-Jin; Zhu, Ka-Di

2011-02-04

Laser and strong coupling can coexist in a single quantum dot (QD) coupled to a photonic crystal nanocavity. This provides an important clue towards the realization of a quantum optical transistor. Using experimentally realistic parameters, in this work, theoretical analysis shows that such a quantum optical transistor can be switched on or off by turning on or off the pump laser, which corresponds to attenuation or amplification of the probe laser, respectively. Furthermore, based on this quantum optical transistor, an all-optical measurement of the vacuum Rabi splitting is also presented. The idea of associating a quantum optical transistor with this coupled QD-nanocavity system may achieve images of light controlling light in all-optical logic circuits and quantum computers.

Insights into the complex interaction between hydrophilic nanoparticles and ionic surfactants at the liquid/air interface.

PubMed

Jin, Jingyu; Li, Xiaoyan; Geng, Jiafeng; Jing, Dengwei

2018-06-06

Combinations of nanoparticles and surfactants have been widely employed in many industrial processes, i.e., boiling and condensation in heat transfer and hydraulic fracturing in shale oil and gas production, etc. However, the underlying mechanism for various phenomena resulting from the addition of nanoparticles into the surfactant solutions is still unclear. For instance, there are contradictory conclusions from the literature regarding the variations of surface tension upon the addition of nanoparticles into surfactant solutions. In this work, the dominating factors determining if the surface activity of the surfactant solution will increase or conversely decrease when adding certain kinds of nanoparticles have been investigated. Two typical hydrophilic nanoparticles, SiO2 and TiO2 with anionic or cationic surfactants, respectively, have been considered. The surface tension has been measured in a wide range of nanoparticle and surfactant concentrations. It was found that the surface tension of the ionic surfactant solution can be further reduced only if nanoparticles of the same charge were added. For instance, a system containing 0.25 CMC SDS and 1 wt% SiO2 behaves similar to a 0.34 CMC SDS-only solution. Interestingly, the observed synergistic effect is found to be more significant if the surfactant concentration is much lower than its CMC for a given nanoparticle content. Moreover, the effect is perfectly reversible. When the nanoparticles were separated from the system, the surface tension values recovered fully to that of the pure surfactants. If nanoparticles of opposite charge were added, however, the surface tension of the surfactant solution increased. Zeta potential measurement and centrifugal treatment have been employed to reveal the interplay between nanoparticles and surfactants and the adsorption behavior of their assemblies at the liquid/air interface. Based on the experimental outcomes, a possible physical mechanism was proposed. It was concluded

BEHAVE: fire behavior prediction and fuel modeling system - BURN subsystem, Part 2

Treesearch

Patricia L. Andrews; Carolyn H. Chase

1989-01-01

This is the third publication describing the BEHAVE system of computer programs for predicting behavior of wildland fires. This publication adds the following predictive capabilities: distance firebrands are lofted ahead of a wind-driven surface fire, probabilities of firebrands igniting spot fires, scorch height of trees, and percentage of tree mortality. The system...

Silicon Carbide Transistor For Detecting Hydrocarbon Gases

NASA Technical Reports Server (NTRS)

Shields, Virgil B.; Ryan, Margaret A.; Williams, Roger M.

1996-01-01

Proposed silicon carbide variable-potential insulated-gate field-effect transistor specially designed for use in measuring concentrations of hydrocarbon gases. Devices like this prove useful numerous automotive, industrial, aeronautical, and environmental monitoring applications.

VO2-based radiative thermal transistor with a semi-transparent base

NASA Astrophysics Data System (ADS)

Prod'homme, Hugo; Ordonez-Miranda, Jose; Ezzahri, Younès; Drévillon, Jérémie; Joulain, Karl

2018-05-01

We study a radiative thermal transistor analogous to an electronic one made of a VO2 base placed between two silica semi-infinite plates playing the roles of the transistor collector and emitter. The fact that VO2 exhibits an insulator to metal transition is exploited to modulate and/or amplify heat fluxes between the emitter and the collector, by applying a thermal current on the VO2 base. We extend the work of precedent studies considering the case where the base can be semi-transparent so that heat can be exchanged directly between the collector and the emitter. Both near and far field cases are considered leading to 4 typical regimes resulting from the fact that the emitter-base and base-collector separation distances can be larger or smaller than the thermal wavelength for a VO2 layer opaque or semi-transparent. Thermal currents variations with the base temperatures are calculated and analyzed. It is found that the transistor can operate in an amplification mode as already stated in [1] or in a switching mode as seen in [2]. An optimum configuration for the base thickness and separation distance maximizing the thermal transistor modulation factor is found.

Modeling of a Metal-Ferroelectric-Semiconductor Field-Effect Transistor NAND Gate

NASA Technical Reports Server (NTRS)

Phillips, Thomas A.; MacLeod, Todd C.; Ho, Fat Duen

2005-01-01

Considerable research has been performed by several organizations in the use of the Metal- Ferroelectric-Semiconductor Field-Effect Transistors (MFSFET) in memory circuits. However, research has been limited in expanding the use of the MFSFET to other electronic circuits. This research project investigates the modeling of a NAND gate constructed from MFSFETs. The NAND gate is one of the fundamental building blocks of digital electronic circuits. The first step in forming a NAND gate is to develop an inverter circuit. The inverter circuit was modeled similar to a standard CMOS inverter. A n-channel MFSFET with positive polarization was used for the n-channel transistor, and a n-channel MFSFET with negative polarization was used for the p-channel transistor. The MFSFETs were simulated by using a previously developed current model which utilized a partitioned ferroelectric layer. The inverter voltage transfer curve was obtained over a standard input of zero to five volts. Then a 2-input NAND gate was modeled similar to the inverter circuit. Voltage transfer curves were obtained for the NAND gate for various configurations of input voltages. The resultant data shows that it is feasible to construct a NAND gate with MFSFET transistors.

Abnormal Multiple Charge Memory States in Exfoliated Few-Layer WSe2 Transistors.

PubMed

Chen, Mikai; Wang, Yifan; Shepherd, Nathan; Huard, Chad; Zhou, Jiantao; Guo, L J; Lu, Wei; Liang, Xiaogan

2017-01-24

To construct reliable nanoelectronic devices based on emerging 2D layered semiconductors, we need to understand the charge-trapping processes in such devices. Additionally, the identified charge-trapping schemes in such layered materials could be further exploited to make multibit (or highly desirable analog-tunable) memory devices. Here, we present a study on the abnormal charge-trapping or memory characteristics of few-layer WSe 2 transistors. This work shows that multiple charge-trapping states with large extrema spacing, long retention time, and analog tunability can be excited in the transistors made from mechanically exfoliated few-layer WSe 2 flakes, whereas they cannot be generated in widely studied few-layer MoS 2 transistors. Such charge-trapping characteristics of WSe 2 transistors are attributed to the exfoliation-induced interlayer deformation on the cleaved surfaces of few-layer WSe 2 flakes, which can spontaneously form ambipolar charge-trapping sites. Our additional results from surface characterization, charge-retention characterization at different temperatures, and density functional theory computation strongly support this explanation. Furthermore, our research also demonstrates that the charge-trapping states excited in multiple transistors can be calibrated into consistent multibit data storage levels. This work advances the understanding of the charge memory mechanisms in layered semiconductors, and the observed charge-trapping states could be further studied for enabling ultralow-cost multibit analog memory devices.

Comparison between Field Effect Transistors and Bipolar Junction Transistors as Transducers in Electrochemical Sensors

NASA Astrophysics Data System (ADS)

Zafar, Sufi; Lu, Minhua; Jagtiani, Ashish

2017-01-01

Field effect transistors (FET) have been widely used as transducers in electrochemical sensors for over 40 years. In this report, a FET transducer is compared with the recently proposed bipolar junction transistor (BJT) transducer. Measurements are performed on two chloride electrochemical sensors that are identical in all details except for the transducer device type. Comparative measurements show that the transducer choice significantly impacts the electrochemical sensor characteristics. Signal to noise ratio is 20 to 2 times greater for the BJT sensor. Sensitivity is also enhanced: BJT sensing signal changes by 10 times per pCl, whereas the FET signal changes by 8 or less times. Also, sensor calibration curves are impacted by the transducer choice. Unlike a FET sensor, the calibration curve of the BJT sensor is independent of applied voltages. Hence, a BJT sensor can make quantitative sensing measurements with minimal calibration requirements, an important characteristic for mobile sensing applications. As a demonstration for mobile applications, these BJT sensors are further investigated by measuring chloride levels in artificial human sweat for potential cystic fibrosis diagnostic use. In summary, the BJT device is demonstrated to be a superior transducer in comparison to a FET in an electrochemical sensor.

Polarization dependent photo-induced bias stress effect in organic transistors.

NASA Astrophysics Data System (ADS)

Podzorov, Vitaly; Choi, Hyun Ho; Najafov, Hikmet; Saranin, Danila; Kharlamov, Nikolai A.; Kuznetzov, Denis V.; Didenko, Sergei I.; Cho, Kilwon; Briseno, Alejandro L.; Rutgers-Misis Collaboration; Ru-P Collaboration; Ru-Um Collaboration; Um-P Collaboration

Photo-induced charge transfer between a semiconductor and a gate insulator that occurs in organic transistors operating under illumination leads to a shift of the onset gate voltage in these devices. Here we report an observation of a polarization dependent photo-induced bias-stress effect in two prototypical single-crystal organic field-effect transistors, based on rubrene and TPBIQ. We find that the rate of the effect is a periodic function of polarization angle of a linearly polarized photoexcitation, with a periodicity of π. The observed phenomenon provides an effective tool for addressing the relationship between molecular packing and parameter drift in organic transistors under illumination. The work was carried out with financial support from the Ministry of Education and Science of the Russian Federation in the framework of Increase Competitiveness Program of NUST «MISiS» (No. K3-2016-004), by gov. decree 16/03/2013, N 211.

Spin-based single-photon transistor, dynamic random access memory, diodes, and routers in semiconductors

NASA Astrophysics Data System (ADS)

Hu, C. Y.

2016-12-01

The realization of quantum computers and quantum Internet requires not only quantum gates and quantum memories, but also transistors at single-photon levels to control the flow of information encoded on single photons. Single-photon transistor (SPT) is an optical transistor in the quantum limit, which uses a single photon to open or block a photonic channel. In sharp contrast to all previous SPT proposals which are based on single-photon nonlinearities, here I present a design for a high-gain and high-speed (up to THz) SPT based on a linear optical effect: giant circular birefringence induced by a single spin in a double-sided optical microcavity. A gate photon sets the spin state via projective measurement and controls the light propagation in the optical channel. This spin-cavity transistor can be directly configured as diodes, routers, DRAM units, switches, modulators, etc. Due to the duality as quantum gate and transistor, the spin-cavity unit provides a solid-state platform ideal for future Internet: a mixture of all-optical Internet with quantum Internet.

Carbon nanotube transistors scaled to a 40-nanometer footprint.

PubMed

Cao, Qing; Tersoff, Jerry; Farmer, Damon B; Zhu, Yu; Han, Shu-Jen

2017-06-30

The International Technology Roadmap for Semiconductors challenges the device research community to reduce the transistor footprint containing all components to 40 nanometers within the next decade. We report on a p-channel transistor scaled to such an extremely small dimension. Built on one semiconducting carbon nanotube, it occupies less than half the space of leading silicon technologies, while delivering a significantly higher pitch-normalized current density-above 0.9 milliampere per micrometer at a low supply voltage of 0.5 volts with a subthreshold swing of 85 millivolts per decade. Furthermore, we show transistors with the same small footprint built on actual high-density arrays of such nanotubes that deliver higher current than that of the best-competing silicon devices under the same overdrive, without any normalization. We achieve this using low-resistance end-bonded contacts, a high-purity semiconducting carbon nanotube source, and self-assembly to pack nanotubes into full surface-coverage aligned arrays. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Flexible organic transistors and circuits with extreme bending stability

NASA Astrophysics Data System (ADS)

Sekitani, Tsuyoshi; Zschieschang, Ute; Klauk, Hagen; Someya, Takao

2010-12-01

Flexible electronic circuits are an essential prerequisite for the development of rollable displays, conformable sensors, biodegradable electronics and other applications with unconventional form factors. The smallest radius into which a circuit can be bent is typically several millimetres, limited by strain-induced damage to the active circuit elements. Bending-induced damage can be avoided by placing the circuit elements on rigid islands connected by stretchable wires, but the presence of rigid areas within the substrate plane limits the bending radius. Here we demonstrate organic transistors and complementary circuits that continue to operate without degradation while being folded into a radius of 100μm. This enormous flexibility and bending stability is enabled by a very thin plastic substrate (12.5μm), an atomically smooth planarization coating and a hybrid encapsulation stack that places the transistors in the neutral strain position. We demonstrate a potential application as a catheter with a sheet of transistors and sensors wrapped around it that enables the spatially resolved measurement of physical or chemical properties inside long, narrow tubes.

Giant current fluctuations in an overheated single-electron transistor

NASA Astrophysics Data System (ADS)

Laakso, M. A.; Heikkilä, T. T.; Nazarov, Yuli V.

2010-11-01

Interplay of cotunneling and single-electron tunneling in a thermally isolated single-electron transistor leads to peculiar overheating effects. In particular, there is an interesting crossover interval where the competition between cotunneling and single-electron tunneling changes to the dominance of the latter. In this interval, the current exhibits anomalous sensitivity to the effective electron temperature of the transistor island and its fluctuations. We present a detailed study of the current and temperature fluctuations at this interesting point. The methods implemented allow for a complete characterization of the distribution of the fluctuating quantities, well beyond the Gaussian approximation. We reveal and explore the parameter range where, for sufficiently small transistor islands, the current fluctuations become gigantic. In this regime, the optimal value of the current, its expectation value, and its standard deviation differ from each other by parametrically large factors. This situation is unique for transport in nanostructures and for electron transport in general. The origin of this spectacular effect is the exponential sensitivity of the current to the fluctuating effective temperature.

Balanced Ambipolar Organic Field-Effect Transistors by Polymer Preaggregation.

PubMed

Janasz, Lukasz; Luczak, Adam; Marszalek, Tomasz; Dupont, Bertrand G R; Jung, Jaroslaw; Ulanski, Jacek; Pisula, Wojciech

2017-06-21

Ambipolar organic field-effect transistors (OFETs) based on heterojunction active films still suffer from an imbalance in the transport of electrons and holes. This problem is related to an uncontrolled phase separation between the donor and acceptor organic semiconductors in the thin films. In this work, we have developed a concept to improve the phase separation in heterojunction transistors to enhance their ambipolar performance. This concept is based on preaggregation of the donor polymer, in this case poly(3-hexylthiophene) (P3HT), before solution mixing with the small-molecular-weight acceptor, phenyl-C61-butyric acid methyl ester (PCBM). The resulting heterojunction transistor morphology consists of self-assembled P3HT fibers embedded in a PCBM matrix, ensuring balanced mobilities reaching 0.01 cm 2 /V s for both holes and electrons. These are the highest mobility values reported so far for ambipolar OFETs based on P3HT/PCBM blends. Preaggregation of the conjugated polymer before fabricating binary blends can be regarded as a general concept for a wider range of semiconducting systems applicable in organic electronic devices.

Polymer-electrolyte-gated nanowire synaptic transistors for neuromorphic applications

NASA Astrophysics Data System (ADS)

Zou, Can; Sun, Jia; Gou, Guangyang; Kong, Ling-An; Qian, Chuan; Dai, Guozhang; Yang, Junliang; Guo, Guang-hua

2017-09-01

Polymer-electrolytes are formed by dissolving a salt in polymer instead of water, the conducting mechanism involves the segmental motion-assisted diffusion of ion in the polymer matrix. Here, we report on the fabrication of tin oxide (SnO2) nanowire synaptic transistors using polymer-electrolyte gating. A thin layer of poly(ethylene oxide) and lithium perchlorate (PEO/LiClO4) was deposited on top of the devices, which was used to boost device performances. A voltage spike applied on the in-plane gate attracts ions toward the polymer-electrolyte/SnO2 nanowire interface and the ions are gradually returned after the pulse is removed, which can induce a dynamic excitatory postsynaptic current in the nanowire channel. The SnO2 synaptic transistors exhibit the behavior of short-term plasticity like the paired-pulse facilitation and self-adaptation, which is related to the electric double-effect regulation. In addition, the synaptic logic functions and the logical function transformation are also discussed. Such single SnO2 nanowire-based synaptic transistors are of great importance for future neuromorphic devices.

Radiation-stimulated processes in transistor temperature sensors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pavlyk, B. V.; Grypa, A. S.

2016-05-15

The features of the radiation-stimulated changes in the I–V and C–V characteristics of the emitter–base junction in KT3117 transistors are considered. It is shown that an increase in the current through the emitter junction is observed at the initial stage of irradiation (at doses of D < 4000 Gy for the “passive” irradiation mode and D < 5200 Gy for the “active” mode), which is caused by the effect of radiation-stimulated ordering of the defect-containing structure of the p–n junction. It is also shown that the X-ray irradiation (D < 14000 Gy), the subsequent relaxation (96 h), and thermal annealingmore » (2 h at 400 K) of the transistor temperature sensors under investigation result in an increase in their radiation resistance.« less

Development of ion implanted gallium arsenide transistors

NASA Technical Reports Server (NTRS)

Hunsperger, R.; Baron, R.

1972-01-01

Techniques were developed for creating bipolar microwave transistors in GaAs by ion implantation doping. The electrical properties of doped layers produced by the implantation of the light ions Be, Mg, and S were studied. Be, Mg, and S are suitable for forming the relatively deep base-collector junction at low ion energies. The electrical characteristics of ion-implanted diodes of both the mesa and planar types were determined. Some n-p-n planar transistor structures were fabricated by implantation of Mg to form the base regions and Si to form the emitters. These devices were found to have reasonably good base-collector and emitter-base junctions, but the current gain beta was small. The low was attributable to radiative recombination in the base region, which was extremely wide.

Terahertz signal detection in a short gate length field-effect transistor with a two-dimensional electron gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vostokov, N. V., E-mail: vostokov@ipm.sci-nnov.ru; Shashkin, V. I.

2015-11-28

We consider the problem of non-resonant detection of terahertz signals in a short gate length field-effect transistor having a two-dimensional electron channel with zero external bias between the source and the drain. The channel resistance, gate-channel capacitance, and quadratic nonlinearity parameter of the transistor during detection as a function of the gate bias voltage are studied. Characteristics of detection of the transistor connected in an antenna with real impedance are analyzed. The consideration is based on both a simple one-dimensional model of the transistor and allowance for the two-dimensional distribution of the electric field in the transistor structure. The resultsmore » given by the different models are discussed.« less

The Integration and Applications of Organic Thin Film Transistors and Ferroelectric Polymers

NASA Astrophysics Data System (ADS)

Hsu, Yu-Jen

Organic thin film transistors and ferroelectric polymer (polyvinylidene difluoride) sheet material are integrated to form various sensors for stress/strain, acoustic wave, and Infrared (heat) sensing applications. Different from silicon-based transistors, organic thin film transistors can be fabricated and processed in room-temperature and integrated with a variety of substrates. On the other hand, polyvinylidene difluoride (PVDF) exhibits ferroelectric properties that are highly useful for sensor applications. The wide frequency bandwidth (0.001 Hz to 10 GHz), vast dynamic range (100n to 10M psi), and high elastic compliance (up to 3 percent) make PVDF a more suitable candidate over ceramic piezoelectric materials for thin and flexible sensor applications. However, the low Curie temperature may have impeded its integration with silicon technology. Organic thin film transistors, however, do not have the limitation of processing temperature, hence can serve as transimpedance amplifiers to convert the charge signal generated by PVDF into current signal that are more measurable and less affected by any downstream parasitics. Piezoelectric sensors are useful for a range of applications, but passive arrays suffer from crosstalk and signal attenuation which have complicated the development of array-based PVDF sensors. We have used organic field effect transistors, which are compatible with the low Curie temperature of a flexible piezoelectric polymer,PVDF, to monolithically fabricate transimpedance amplifiers directly on the sensor surface and convert the piezoelectric charge signal into a current signal which can be detected even in the presence of parasitic capacitances. The device couples the voltage generated by the PVDF film under strain into the gate of the organic thin film transistors (OFET) using an arrangement that allows the full piezoelectric voltage to couple to the channel, while also increasing the charge retention time. A bipolar detector is created by

Gallium nitride junction field-effect transistor

DOEpatents

Zolper, J.C.; Shul, R.J.

1999-02-02

An ion implanted gallium-nitride (GaN) junction field-effect transistor (JFET) and method of making the same are disclosed. Also disclosed are various ion implants, both n- and p-type, together with or without phosphorus co-implantation, in selected III-V semiconductor materials. 19 figs.

Phase-locked loop based on nanoelectromechanical resonant-body field effect transistor

NASA Astrophysics Data System (ADS)

Bartsch, S. T.; Rusu, A.; Ionescu, A. M.

2012-10-01

We demonstrate the room-temperature operation of a silicon nanoelectromechanical resonant-body field effect transistor (RB-FET) embedded into phase-locked loop (PLL). The very-high frequency resonator uses on-chip electrostatic actuation and transistor-based displacement detection. The heterodyne frequency down-conversion based on resistive FET mixing provides a loop feedback signal with high signal-to-noise ratio. We identify key parameters for PLL operation, and analyze the performance of the RB-FET at the system level. Used as resonant mass detector, the experimental frequency stability in the ppm-range translates into sub atto-gram (10-18 g) sensitivity in high vacuum. The feedback and control system are generic and may be extended to other mechanical resonators with transistor properties, such as graphene membranes and carbon nanotubes.

Properties of polycarbonate containing BaTiO{sub 3} nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lomax, J. F.; Lomax, E. A.; Lomax, P. Q.

2014-03-14

The real part of the relative permittivity, ε′, and dielectric loss, tan δ, have been determined at audio frequencies at temperatures from about 5 K to 350 K for nano-composites composed of BaTiO{sub 3} nanoparticles and polycarbonate. The room temperature breakdown strength was also measured and thermal analysis, nuclear magnetic resonance and scanning electron microscopy studies were carried out. For some films the nanoparticles were surface-treated (STNP) while for others they were not (UNP). For concentrations of UNP greater than about 3.4 vol. %, ε′ is much larger than expected on the basis of laws of mixing. On the other hand, ε′ formore » materials made using STNP is well-behaved. Correspondingly, increased loss (ε″ or tan δ) in the vicinity of room temperature is observed for the materials made from UNP. The anomalously large values of relative permittivity and increased loss are attributed to the presence of large aggregates in the materials made using the UNP. For both UNP-and STNP-based materials, the breakdown strength is found to decrease as nanoparticle concentration increases. The breakdown strength for the materials made using STNP is found to be larger for all concentrations than for those containing UNP despite the presence of large aggregates in some of the STNP-based materials. This shows that breakdown is strongly affected by the nanoparticle surfaces and/or the interface layer. It is also found that the breakdown strength for materials made using UNP increases as particle size increases. Finally, variable temperature and pressure proton nuclear magnetic resonance relaxation measurements were made to assess the effect of nanoparticle inclusion on polymer motion, and the effects were found to be very minor.« less

On-Chip Sorting of Long Semiconducting Carbon Nanotubes for Multiple Transistors along an Identical Array.

PubMed

Otsuka, Keigo; Inoue, Taiki; Maeda, Etsuo; Kometani, Reo; Chiashi, Shohei; Maruyama, Shigeo

2017-11-28

Ballistic transport and sub-10 nm channel lengths have been achieved in transistors containing one single-walled carbon nanotube (SWNT). To fill the gap between single-tube transistors and high-performance logic circuits for the replacement of silicon, large-area, high-density, and purely semiconducting (s-) SWNT arrays are highly desired. Here we demonstrate the fabrication of multiple transistors along a purely semiconducting SWNT array via an on-chip purification method. Water- and polymer-assisted burning from site-controlled nanogaps is developed for the reliable full-length removal of metallic SWNTs with the damage to s-SWNTs minimized even in high-density arrays. All the transistors with various channel lengths show large on-state current and excellent switching behavior in the off-state. Since our method potentially provides pure s-SWNT arrays over a large area with negligible damage, numerous transistors with arbitrary dimensions could be fabricated using a conventional semiconductor process, leading to SWNT-based logic, high-speed communication, and other next-generation electronic devices.

Tetherless near-infrared control of brain activity in behaving animals using fully implantable upconversion microdevices.

PubMed

Wang, Ying; Lin, Xudong; Chen, Xi; Chen, Xian; Xu, Zhen; Zhang, Wenchong; Liao, Qinghai; Duan, Xin; Wang, Xin; Liu, Ming; Wang, Feng; He, Jufang; Shi, Peng

2017-10-01

Many nanomaterials can be used as sensors or transducers in biomedical research and they form the essential components of transformative novel biotechnologies. In this study, we present an all-optical method for tetherless remote control of neural activity using fully implantable micro-devices based on upconversion technology. Upconversion nanoparticles (UCNPs) were used as transducers to convert near-infrared (NIR) energy to visible light in order to stimulate neurons expressing different opsin proteins. In our setup, UCNPs were packaged in a glass micro-optrode to form an implantable device with superb long-term biocompatibility. We showed that remotely applied NIR illumination is able to reliably trigger spiking activity in rat brains. In combination with a robotic laser projection system, the upconversion-based tetherless neural stimulation technique was implemented to modulate brain activity in various regions, including the striatum, ventral tegmental area, and visual cortex. Using this system, we were able to achieve behavioral conditioning in freely moving animals. Notably, our microscale device was at least one order of magnitude smaller in size (∼100 μm in diameter) and two orders of magnitude lighter in weight (less than 1 mg) than existing wireless optogenetic devices based on light-emitting diodes. This feature allows simultaneous implantation of multiple UCNP-optrodes to achieve modulation of brain function to control complex animal behavior. We believe that this technology not only represents a novel practical application of upconversion nanomaterials, but also opens up new possibilities for remote control of neural activity in the brains of behaving animals. Copyright © 2017 Elsevier Ltd. All rights reserved.

Benchmarking organic mixed conductors for transistors.

PubMed

Inal, Sahika; Malliaras, George G; Rivnay, Jonathan

2017-11-24

Organic mixed conductors have garnered significant attention in applications from bioelectronics to energy storage/generation. Their implementation in organic transistors has led to enhanced biosensing, neuromorphic function, and specialized circuits. While a narrow class of conducting polymers continues to excel in these new applications, materials design efforts have accelerated as researchers target new functionality, processability, and improved performance/stability. Materials for organic electrochemical transistors (OECTs) require both efficient electronic transport and facile ion injection in order to sustain high capacity. In this work, we show that the product of the electronic mobility and volumetric charge storage capacity (µC*) is the materials/system figure of merit; we use this framework to benchmark and compare the steady-state OECT performance of ten previously reported materials. This product can be independently verified and decoupled to guide materials design and processing. OECTs can therefore be used as a tool for understanding and designing new organic mixed conductors.

Evolution of a designless nanoparticle network into reconfigurable Boolean logic

NASA Astrophysics Data System (ADS)

Bose, S. K.; Lawrence, C. P.; Liu, Z.; Makarenko, K. S.; van Damme, R. M. J.; Broersma, H. J.; van der Wiel, W. G.

2015-12-01

Natural computers exploit the emergent properties and massive parallelism of interconnected networks of locally active components. Evolution has resulted in systems that compute quickly and that use energy efficiently, utilizing whatever physical properties are exploitable. Man-made computers, on the other hand, are based on circuits of functional units that follow given design rules. Hence, potentially exploitable physical processes, such as capacitive crosstalk, to solve a problem are left out. Until now, designless nanoscale networks of inanimate matter that exhibit robust computational functionality had not been realized. Here we artificially evolve the electrical properties of a disordered nanomaterials system (by optimizing the values of control voltages using a genetic algorithm) to perform computational tasks reconfigurably. We exploit the rich behaviour that emerges from interconnected metal nanoparticles, which act as strongly nonlinear single-electron transistors, and find that this nanoscale architecture can be configured in situ into any Boolean logic gate. This universal, reconfigurable gate would require about ten transistors in a conventional circuit. Our system meets the criteria for the physical realization of (cellular) neural networks: universality (arbitrary Boolean functions), compactness, robustness and evolvability, which implies scalability to perform more advanced tasks. Our evolutionary approach works around device-to-device variations and the accompanying uncertainties in performance. Moreover, it bears a great potential for more energy-efficient computation, and for solving problems that are very hard to tackle in conventional architectures.

Depletion type floating gate p-channel MOS transistor for recording action potentials generated by cultured neurons.

PubMed

Cohen, Ariel; Spira, Micha E; Yitshaik, Shlomo; Borghs, Gustaaf; Shwartzglass, Ofer; Shappir, Joseph

2004-07-15

We report the realization of electrical coupling between neurons and depletion type floating gate (FG) p-channel MOS transistors. The devices were realized in a shortened 0.5 microm CMOS technology. Increased boron implant dose was used to form the depletion type devices. Post-CMOS processing steps were added to expose the devices sensing area. The neurons are coupled to the polycrystalline silicon (PS) FG through 420A thermal oxide in an area which is located over the thick field oxide away from the transistor. The combination of coupling area pad having a diameter of 10 or 15 microm and sensing transistor with W/L of 50/0.5 microm results in capacitive coupling ratio of the neuron signal of about 0.5 together with relatively large transistor transconductance. The combination of the FG structure with a depletion type device, leads to the following advantages. (a) No need for dc bias between the solution in which the neurons are cultured and the transistor with expected consequences to the neuron as well as the silicon die durability. (b) The sensing area of the neuron activity is separated from the active area of the transistor. Thus, it is possible to design the sensing area and the channel area separately. (c) The channel area, which is the most sensitive part of the transistor, can be insulated and shielded from the ionic solution in which the neurons are cultured. (d) There is an option to add a switching transistor to the FG and use the FG also for the neuron stimulation.

A programmable closed-loop recording and stimulating wireless system for behaving small laboratory animals

PubMed Central

Angotzi, Gian Nicola; Boi, Fabio; Zordan, Stefano; Bonfanti, Andrea; Vato, Alessandro

2014-01-01

A portable 16-channels microcontroller-based wireless system for a bi-directional interaction with the central nervous system is presented in this work. The device is designed to be used with freely behaving small laboratory animals and allows recording of spontaneous and evoked neural activity wirelessly transmitted and stored on a personal computer. Biphasic current stimuli with programmable duration, frequency and amplitude may be triggered in real-time on the basis of the recorded neural activity as well as by the animal behavior within a specifically designed experimental setup. An intuitive graphical user interface was developed to configure and to monitor the whole system. The system was successfully tested through bench tests and in vivo measurements on behaving rats chronically implanted with multi-channels microwire arrays. PMID:25096831

High-mobility field-effect transistor based on crystalline ZnSnO3 thin films

NASA Astrophysics Data System (ADS)

Minato, Hiroya; Fujiwara, Kohei; Tsukazaki, Atsushi

2018-05-01

We propose crystalline ZnSnO3 as a new channel material for field-effect transistors. By molecular-beam epitaxy on LiNbO3(0001) substrates, we synthesized films of ZnSnO3, which crystallizes in the LiNbO3-type polar structure. Field-effect transistors on ZnSnO3 exhibit n-type operation with field-effect mobility of as high as 45 cm2V-1s-1 at room temperature. Systematic examination of the transistor operation for channels with different Zn/Sn compositional ratios revealed that the observed high-mobility reflects the nature of stoichiometric ZnSnO3 phase. Moreover, we found an indication of coupling of transistor characteristics with intrinsic spontaneous polarization in ZnSnO3, potentially leading to a distinct type of polarization-induced conduction.

Biomolecular detection using a metal semiconductor field effect transistor

NASA Astrophysics Data System (ADS)

Estephan, Elias; Saab, Marie-Belle; Buzatu, Petre; Aulombard, Roger; Cuisinier, Frédéric J. G.; Gergely, Csilla; Cloitre, Thierry

2010-04-01

In this work, our attention was drawn towards developing affinity-based electrical biosensors, using a MESFET (Metal Semiconductor Field Effect Transistor). Semiconductor (SC) surfaces must be prepared before the incubations with biomolecules. The peptides route was adapted to exceed and bypass the limits revealed by other types of surface modification due to the unwanted unspecific interactions. As these peptides reveal specific recognition of materials, then controlled functionalization can be achieved. Peptides were produced by phage display technology using a library of M13 bacteriophage. After several rounds of bio-panning, the phages presenting affinities for GaAs SC were isolated; the DNA of these specific phages were sequenced, and the peptide with the highest affinity was synthesized and biotinylated. To explore the possibility of electrical detection, the MESFET fabricated with the GaAs SC were used to detect the streptavidin via the biotinylated peptide in the presence of the bovine Serum Albumin. After each surface modification step, the IDS (current between the drain and the source) of the transistor was measured and a decrease in the intensity was detected. Furthermore, fluorescent microscopy was used in order to prove the specificity of this peptide and the specific localisation of biomolecules. In conclusion, the feasibility of producing an electrical biosensor using a MESFET has been demonstrated. Controlled placement, specific localization and detection of biomolecules on a MESFET transistor were achieved without covering the drain and the source. This method of functionalization and detection can be of great utility for biosensing application opening a new way for developing bioFETs (Biomolecular Field-Effect Transistor).

Benzocyclobutene (BCB) Polymer as Amphibious Buffer Layer for Graphene Field-Effect Transistor.

PubMed

Wu, Yun; Zou, Jianjun; Huo, Shuai; Lu, Haiyan; Kong, Yuecan; Chen, Tangshen; Wu, Wei; Xu, Jingxia

2015-08-01

Owing to the scattering and trapping effects, the interfaces of dielectric/graphene or substrate/graphene can tailor the performance of field-effect transistor (FET). In this letter, the polymer of benzocyclobutene (BCB) was used as an amphibious buffer layer and located at between the layers of substrate and graphene and between the layers of dielectric and graphene. Interestingly, with the help of nonpolar and hydrophobic BCB buffer layer, the large-scale top-gated, chemical vapor deposited (CVD) graphene transistors was prepared on Si/SiO2 substrate, its cutoff frequency (fT) and the maximum cutoff frequency (fmax) of the graphene field-effect transistor (GFET) can be reached at 12 GHz and 11 GHz, respectively.

Linker-mediated assembly of gold nanoparticles into multimeric motifs

NASA Astrophysics Data System (ADS)

Sikora, Mateusz; Szymczak, Piotr; Thompson, Damien; Cieplak, Marek

2011-11-01

We present a theoretical description of linker-mediated self-assembly of gold nanoparticles (Au-NP). Using mesoscale simulations with a coarse-grained model for the Au NPs and dirhenium-based linker molecules, we investigate the conditions under which large clusters can grow and construct a phase diagram that identifies favorable growth conditions in terms of floating and bound linker concentrations. The findings can be considered as generic, as we expect other NP-linker systems to behave in a qualitatively similar way. In particular, we also discuss the case of antibody-functionalised Au NPs connected by the C-reactive proteins (CRPs). We extract some general rules for NP linking that may aid the production of size- and shape-specific NP clusters for technology applications.

Inverter Circuits using Pentacene and ZnO Transistors

NASA Astrophysics Data System (ADS)

Iechi, Hiroyuki; Watanabe, Yasuyuki; Kudo, Kazuhiro

2007-04-01

We report two types of integrated circuits based on a pentacene static-induction transistor (SIT), a pentacene thin-film transistor (TFT) and a zinc oxide (ZnO) TFT. The operating characteristics of a p-p inverter using pentacene SITs and a complementary inverter using a p-channel pentacene TFT and an n-channel ZnO TFT are described. The basic operation of logic circuits at a low voltage was achieved for the first time using the pentacene SIT inverter and complementary circuits with hybrid inorganic and organic materials. Furthermore, we describe the electrical properties of the ZnO films depending on sputtering conditions, and the complementary circuits using ZnO and pentacene TFTs.

Investigation of Monodisperse Dendrimeric Polysaccharide Nanoparticle Dispersions Using Small Angle Neutron Scattering

NASA Astrophysics Data System (ADS)

Atkinson, John; Nickels, Jonathan; Papp-Szabo, Erzsi; Katsaras, John; Dutcher, John

2015-03-01

Phytoglycogen is a highly branched polysaccharide that is very similar to the energy storage molecule glycogen. We have isolated monodisperse phytoglycogen nanoparticles from corn and these particles are attractive for applications in the cosmetic, food and beverage, and biomedical industries. Many of these promising applications are due to the special interaction between the nanoparticles and water, which results in: (1) high solubility; (2) low viscosity and high stability in aqueous dispersions; and (3) a remarkable capacity to sequester and retain water. Our rheology measurements indicate that the nanoparticles behave like hard spheres in water, with the viscosity diverging for concentrations >25% (w/w). Because of this, aqueous suspensions of phytoglycogen provide an ideal platform for detailed testing of theories of colloidal glasses and jamming. To further explore the interaction of the phytoglycogen particles and water, we have performed small angle neutron scattering (SANS) measurements on the Extended Q-Range SANS (EQ-SANS) diffractometer at the Spallation Neutron Source at Oak Ridge National Laboratory. Measurements performed on phytoglycogen dispersions in mixtures of hydrogenated and deuterated water have allowed us to determine the particle size and average particle spacing as a function of the phytoglycogen concentration in the limits of dilute and concentrated dispersions.

Characterization of a Common-Source Amplifier Using Ferroelectric Transistors

NASA Technical Reports Server (NTRS)

Hunt, Mitchell; Sayyah, Rana; MacLeond, Todd C.; Ho, Pat D.

2010-01-01

This paper presents empirical data that was collected through experiments using a FeFET in the established common-source amplifier circuit. The unique behavior of the FeFET lends itself to interesting and useful operation in this widely used common-source amplifier. The paper examines the effect of using a ferroelectric transistor for the amplifier. It also examines the effects of varying load resistance, biasing, and input voltages on the output signal and gives several examples of the output of the amplifier for a given input. The difference between a commonsource amplifier using a ferroelectric transistor and that using a MOSFET is addressed.

Rapid synthesis and decoration of reduced graphene oxide with gold nanoparticles by thermostable peptides for memory device and photothermal applications.

PubMed

Otari, Sachin V; Kumar, Manoj; Anwar, Muhammad Zahid; Thorat, Nanasaheb D; Patel, Sanjay K S; Lee, Dongjin; Lee, Jai Hyo; Lee, Jung-Kul; Kang, Yun Chan; Zhang, Liaoyuan

2017-09-08

This article presents novel, rapid, and environmentally benign synthesis method for one-step reduction and decoration of graphene oxide with gold nanoparticles (NAuNPs) by using thermostable antimicrobial nisin peptides to form a gold-nanoparticles-reduced graphene oxide (NAu-rGO) nanocomposite. The formed composite material was characterized by UV/Vis spectroscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, and high-resolution transmission electron microscopy (HR-TEM). HR-TEM analysis revealed the formation of spherical AuNPs of 5-30 nm in size on reduced graphene oxide (rGO) nanosheets. A non-volatile-memory device was prepared based on a solution-processed ZnO thin-film transistor fabricated by inserting the NAu-rGO nanocomposite in the gate dielectric stack as a charge trapping medium. The transfer characteristic of the ZnO thin-film transistor memory device showed large clockwise hysteresis behaviour because of charge carrier trapping in the NAu-rGO nanocomposite. Under positive and negative bias conditions, clear positive and negative threshold voltage shifts occurred, which were attributed to charge carrier trapping and de-trapping in the ZnO/NAu-rGO/SiO 2 structure. Also, the photothermal effect of the NAu-rGO nanocomposites on MCF7 breast cancer cells caused inhibition of ~80% cells after irradiation with infrared light (0.5 W cm -2 ) for 5 min.

Recent Advances of Solution-Processed Metal Oxide Thin-Film Transistors.

PubMed

Xu, Wangying; Li, Hao; Xu, Jian-Bin; Wang, Lei

2018-03-06

Solution-processed metal oxide thin-film transistors (TFTs) are considered as one of the most promising transistor technologies for future large-area flexible electronics. This review surveys the recent advances in solution-based oxide TFTs, including n-type oxide semiconductors, oxide dielectrics and p-type oxide semiconductors. Firstly, we provide an introduction on oxide TFTs and the TFT configurations and operating principles. Secondly, we present the recent progress in solution-processed n-type transistors, with a special focus on low-temperature and large-area solution processed approaches as well as novel non-display applications. Thirdly, we give a detailed analysis of the state-of-the-art solution-processed oxide dielectrics for low-voltage electronics. Fourthly, we discuss the recent progress in solution-based p-type oxide semiconductors, which will enable the highly desirable future low-cost large-area complementary circuits. Finally, we draw the conclusions and outline the perspectives over the research field.

An Adaptive Cultural Algorithm with Improved Quantum-behaved Particle Swarm Optimization for Sonar Image Detection.

PubMed

Wang, Xingmei; Hao, Wenqian; Li, Qiming

2017-12-18

This paper proposes an adaptive cultural algorithm with improved quantum-behaved particle swarm optimization (ACA-IQPSO) to detect the underwater sonar image. In the population space, to improve searching ability of particles, iterative times and the fitness value of particles are regarded as factors to adaptively adjust the contraction-expansion coefficient of the quantum-behaved particle swarm optimization algorithm (QPSO). The improved quantum-behaved particle swarm optimization algorithm (IQPSO) can make particles adjust their behaviours according to their quality. In the belief space, a new update strategy is adopted to update cultural individuals according to the idea of the update strategy in shuffled frog leaping algorithm (SFLA). Moreover, to enhance the utilization of information in the population space and belief space, accept function and influence function are redesigned in the new communication protocol. The experimental results show that ACA-IQPSO can obtain good clustering centres according to the grey distribution information of underwater sonar images, and accurately complete underwater objects detection. Compared with other algorithms, the proposed ACA-IQPSO has good effectiveness, excellent adaptability, a powerful searching ability and high convergence efficiency. Meanwhile, the experimental results of the benchmark functions can further demonstrate that the proposed ACA-IQPSO has better searching ability, convergence efficiency and stability.

Short-channel field-effect transistors with 9-atom and 13-atom wide graphene nanoribbons.

PubMed

Llinas, Juan Pablo; Fairbrother, Andrew; Borin Barin, Gabriela; Shi, Wu; Lee, Kyunghoon; Wu, Shuang; Yong Choi, Byung; Braganza, Rohit; Lear, Jordan; Kau, Nicholas; Choi, Wonwoo; Chen, Chen; Pedramrazi, Zahra; Dumslaff, Tim; Narita, Akimitsu; Feng, Xinliang; Müllen, Klaus; Fischer, Felix; Zettl, Alex; Ruffieux, Pascal; Yablonovitch, Eli; Crommie, Michael; Fasel, Roman; Bokor, Jeffrey

2017-09-21

Bottom-up synthesized graphene nanoribbons and graphene nanoribbon heterostructures have promising electronic properties for high-performance field-effect transistors and ultra-low power devices such as tunneling field-effect transistors. However, the short length and wide band gap of these graphene nanoribbons have prevented the fabrication of devices with the desired performance and switching behavior. Here, by fabricating short channel (L ch  ~ 20 nm) devices with a thin, high-κ gate dielectric and a 9-atom wide (0.95 nm) armchair graphene nanoribbon as the channel material, we demonstrate field-effect transistors with high on-current (I on  > 1 μA at V d  = -1 V) and high I on /I off  ~ 10 5 at room temperature. We find that the performance of these devices is limited by tunneling through the Schottky barrier at the contacts and we observe an increase in the transparency of the barrier by increasing the gate field near the contacts. Our results thus demonstrate successful fabrication of high-performance short-channel field-effect transistors with bottom-up synthesized armchair graphene nanoribbons.Graphene nanoribbons show promise for high-performance field-effect transistors, however they often suffer from short lengths and wide band gaps. Here, the authors use a bottom-up synthesis approach to fabricate 9- and 13-atom wide ribbons, enabling short-channel transistors with 10 5 on-off current ratio.

N-Channel field-effect transistors with floating gates for extracellular recordings.

PubMed

Meyburg, Sven; Goryll, Michael; Moers, Jürgen; Ingebrandt, Sven; Böcker-Meffert, Simone; Lüth, Hans; Offenhäusser, Andreas

2006-01-15

A field-effect transistor (FET) for recording extracellular signals from electrogenic cells is presented. The so-called floating gate architecture combines a complementary metal oxide semiconductor (CMOS)-type n-channel transistor with an independent sensing area. This concept allows the transistor and sensing area to be optimised separately. The devices are robust and can be reused several times. The noise level of the devices was smaller than of comparable non-metallised gate FETs. In addition to the usual drift of FET devices, we observed a long-term drift that has to be controlled for future long-term measurements. The device performance for extracellular signal recording was tested using embryonic rat cardiac myocytes cultured on fibronectin-coated chips. The extracellular cell signals were recorded before and after the addition of the cardioactive isoproterenol. The signal shapes of the measured action potentials were comparable to the non-metallised gate FETs previously used in similar experiments. The fabrication of the devices involved the process steps of standard CMOS that were necessary to create n-channel transistors. The implementation of a complete CMOS process would facilitate the integration of the logical circuits necessary for signal pre-processing on a chip, which is a prerequisite for a greater number of sensor spots in future layouts.