Solution-Processed Gallium–Tin-Based Oxide Semiconductors for Thin-Film Transistors

PubMed Central

Zhang, Xue; Lee, Hyeonju; Kim, Jungwon; Kim, Eui-Jik; Park, Jaehoon

2017-01-01

We investigated the effects of gallium (Ga) and tin (Sn) compositions on the structural and chemical properties of Ga–Sn-mixed (Ga:Sn) oxide films and the electrical properties of Ga:Sn oxide thin-film transistors (TFTs). The thermogravimetric analysis results indicate that solution-processed oxide films can be produced via thermal annealing at 500 °C. The oxygen deficiency ratio in the Ga:Sn oxide film increased from 0.18 (Ga oxide) and 0.30 (Sn oxide) to 0.36, while the X-ray diffraction peaks corresponding to Sn oxide significantly reduced. The Ga:Sn oxide film exhibited smaller grains compared to the nanocrystalline Sn oxide film, while the Ga oxide film exhibited an amorphous morphology. We found that the electrical properties of TFTs significantly improve by mixing Ga and Sn. Here, the optimum weight ratio of the constituents in the mixture of Ga and Sn precursor sols was determined to be 1.0:0.9 (Ga precursor sol:Sn precursor sol) for application in the solution-processed Ga:Sn oxide TFTs. In addition, when the Ga(1.0):Sn(0.9) oxide film was thermally annealed at 900 °C, the field-effect mobility of the TFT was notably enhanced from 0.02 to 1.03 cm2/Vs. Therefore, the mixing concentration ratio and annealing temperature are crucial for the chemical and morphological properties of solution-processed Ga:Sn oxide films and for the TFT performance. PMID:29283408

Amorphous tin-cadmium oxide films and the production thereof

DOEpatents

Li, Xiaonan; Gessert, Timothy A

2013-10-29

A tin-cadmium oxide film having an amorphous structure and a ratio of tin atoms to cadmium atoms of between 1:1 and 3:1. The tin-cadmium oxide film may have an optical band gap of between 2.7 eV and 3.35 eV. The film may also have a charge carrier concentration of between 1.times.10.sup.20 cm.sup.-3 and 2.times.10.sup.20 cm.sup.-3. The tin cadmium oxide film may also exhibit a Hall mobility of between 40 cm.sup.2V.sup.-1 s.sup.-1 and 60 cm.sup.2V.sup.-1 s.sup.-1. Also disclosed is a method of producing an amorphous tin-cadmium oxide film as described and devices using same.

Methodology for the effective stabilization of tin-oxide-based oxidation/reduction catalysts

NASA Technical Reports Server (NTRS)

Jordan, Jeffrey D. (Inventor); Schryer, David R. (Inventor); Leighty, Bradley D. (Inventor); Watkins, Anthony N. (Inventor); Summers, Jerry C. (Inventor); Davis, Patricia P. (Inventor); Oglesby, Donald M. (Inventor); Schryer, Jacqueline L. (Inventor); Gulati, Suresh T. (Inventor)

2011-01-01

The invention described herein involves a novel approach to the production of oxidation/reduction catalytic systems. The present invention serves to stabilize the tin oxide reducible metal-oxide coating by co-incorporating at least another metal-oxide species, such as zirconium. In one embodiment, a third metal-oxide species is incorporated, selected from the group consisting of cerium, lanthanum, hafnium, and ruthenium. The incorporation of the additional metal oxide components serves to stabilize the active tin-oxide layer in the catalytic process during high-temperature operation in a reducing environment (e.g., automobile exhaust). Moreover, the additional metal oxides are active components due to their oxygen-retention capabilities. Together, these features provide a mechanism to extend the range of operation of the tin-oxide-based catalyst system for automotive applications, while maintaining the existing advantages.

Peroxide induced tin oxide coating of graphene oxide at room temperature and its application for lithium ion batteries.

PubMed

Sladkevich, S; Gun, J; Prikhodchenko, P V; Gutkin, V; Mikhaylov, A A; Novotortsev, V M; Zhu, J X; Yang, D; Hng, H H; Tay, Y Y; Tsakadze, Z; Lev, O

2012-12-07

We describe a new, simple and low-temperature method for ultra-thin coating of graphene oxide (GO) by peroxostannate, tin oxide or a mixture of tin and tin oxide crystallites by different treatments. The technique is environmentally friendly and does not require complicated infrastructure, an autoclave or a microwave. The supported peroxostannate phase is partially converted after drying to crystalline tin oxide with average, 2.5 nm cassiterite crystals. Mild heat treatment yielded full coverage of the reduced graphene oxide by crystalline tin oxide. Extensive heat treatment in vacuum at >500 °C yielded a mixture of elemental tin and cassiterite tin oxide nanoparticles supported on reduced graphene oxide (rGO). The usefulness of the new approach was demonstrated by the preparation of two types of lithium ion anodes: tin oxide-rGO and a mixture of tin oxide and tin coated rGO composites (SnO(2)-Sn-rGO). The electrodes exhibited stable charge/discharge cyclability and high charging capacity due to the intimate contact between the conductive graphene and the very small tin oxide crystallites. The charging/discharging capacity of the anodes exceeded the theoretical capacity predicted based on tin lithiation. The tin oxide coated rGO exhibited higher charging capacity but somewhat lower stability upon extended charge/discharge cycling compared to SnO(2)-Sn-rGO.

Improve oxidation resistance at high temperature by nanocrystalline surface layer

NASA Astrophysics Data System (ADS)

Xia, Z. X.; Zhang, C.; Huang, X. F.; Liu, W. B.; Yang, Z. G.

2015-08-01

An interesting change of scale sequence occurred during oxidation of nanocrystalline surface layer by means of a surface mechanical attrition treatment. The three-layer oxide structure from the surface towards the matrix is Fe3O4, spinel FeCr2O4 and corundum (Fe,Cr)2O3, which is different from the typical two-layer scale consisted of an Fe3O4 outer layer and an FeCr2O4 inner layer in conventional P91 steel. The diffusivity of Cr, Fe and O is enhanced concurrently in the nanocrystalline surface layer, which causes the fast oxidation in the initial oxidation stage. The formation of (Fe,Cr)2O3 inner layer would inhabit fast diffusion of alloy elements in the nanocrystalline surface layer of P91 steel in the later oxidation stage, and it causes a decrease in the parabolic oxidation rate compared with conventional specimens. This study provides a novel approach to improve the oxidation resistance of heat resistant steel without changing its Cr content.

Single-Stroke Synthesis of Tin Sulphide/Oxide Nanocomposites Within Engineering Thermoplastic and Their Humidity Response.

PubMed

Adkar, Dattatraya; Adhyapak, Parag; Mulik, Uttamrao; Jadkar, Sandesh; Vutova, Katia; Amalnerkar, Dinesh

2018-05-01

SnS nanostructured materials have attracted enormous interest due to their important properties and potential application in low cost solar energy conversion systems and optical devices. From the perspective of SnS based device fabrication, we offer single-stroke in-situ technique for the generation of Sn based sulphide and oxide nanostructures inside the polymer network via polymer-inorganic solid state reaction route. In this method, polyphenylene sulphide (PPS)-an engineering thermoplastic-acts as chalcogen source as well as stabilizing matrix for the resultant nano products. Typical solid state reaction was accomplished by simply heating the physical admixtures of the tin salts (viz. tin acetate/tin chloride) with PPS at the crystalline melting temperature (285 °C) of PPS in inert atmosphere. The synthesized products were characterized by using various physicochemical characterization techniques. The prima facie observations suggest the concurrent formation of nanocrystalline SnS with extraneous oxide phase. The TEM analysis revealed formation of nanosized particles of assorted morphological features with polydispersity confined to 5 to 50 nm. However, agglomerated particles of nano to submicron size were also observed. The humidity sensing characterization of these nanocomposites was also performed. The resistivity response with the level of humidity (20 to 85% RH) was compared for these nanocomposites. The linear response was obtained for both the products. Nevertheless, the nanocomposite product obtained from acetate precursor showed higher sensitivity towards the humidity than that of one prepared from chloride precursor.

Effect of aging heat time and annealing temperature on the properties of nanocrystalline tin dioxide thin films

NASA Astrophysics Data System (ADS)

Kadhim, Imad H.; Abu Hassan, H.

2017-04-01

Nanocrystalline tin dioxide (SnO2) thin films have been successfully prepared by sol-gel spin-coating technique on p-type Si (100) substrates. A stable solution was prepared by mixing tin(II) chloride dihydrate, pure ethanol, and glycerin. Temperature affects the properties of SnO2 thin films, particularly the crystallite size where the crystallization of SnO2 with tetragonal rutile structure is achieved when thin films that prepared under different aging heat times are annealed at 400∘C. By increasing aging heat time in the presence of annealing temperatures the FESEM images indicated that the thickness of the fabricated film was directly proportional to solution viscosity, increasing from approximately 380 nm to 744 nm, as well as the crystallization of the thin films improved and reduced defects.

Atomic layer deposition of tin oxide and zinc tin oxide using tetraethyltin and ozone

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

Warner, Ellis J.; Gladfelter, Wayne L., E-mail: wlg@umn.edu; Johnson, Forrest

Silicon or glass substrates exposed to sequential pulses of tetraethyltin (TET) and ozone (O{sub 3}) were coated with thin films of SnO{sub 2}. Self-limiting deposition was found using 8 s pulse times, and a uniform thickness per cycle (TPC) of 0.2 nm/cycle was observed in a small, yet reproducible, temperature window from 290 to 320 °C. The as-deposited, stoichiometric SnO{sub 2} films were amorphous and transparent above 400 nm. Interspersing pulses of diethylzinc and O{sub 3} among the TET:O{sub 3} pulses resulted in deposition of zinc tin oxide films, where the fraction of tin, defined as [at. % Sn/(at. % Sn + at. %more » Zn)], was controlled by the ratio of TET pulses, specifically n{sub TET}:(n{sub TET} + n{sub DEZ}) where n{sub TET} and n{sub DEZ} are the number of precursor/O{sub 3} subcycles within each atomic layer deposition (ALD) supercycle. Based on film thickness and composition measurements, the TET pulse time required to reach saturation in the TPC of SnO{sub 2} on ZnO surfaces was increased to >30 s. Under these conditions, film stoichiometry as a function of the TET pulse ratio was consistent with the model devised by Elliott and Nilsen. The as-deposited zinc tin oxide (ZTO) films were amorphous and remained so even after annealing at 450 °C in air for 1 h. The optical bandgap of the transparent ZTO films increased as the tin concentration increased. Hall measurements established that the n-type ZTO carrier concentration was 3 × 10{sup 17} and 4 × 10{sup 18} cm{sup −3} for fractional tin concentrations of 0.28 and 0.63, respectively. The carrier mobility decreased as the concentration of tin increased. A broken gap pn junction was fabricated using ALD-deposited ZTO and a sputtered layer of cuprous oxide. The junction demonstrated ohmic behavior and low resistance consistent with similar junctions prepared using sputter-deposited ZTO.« less

Synthesis and Characterization of Tin(IV) Oxide Obtained by Chemical Vapor Deposition Method

NASA Astrophysics Data System (ADS)

Nagirnyak, Svitlana V.; Lutz, Victoriya A.; Dontsova, Tatiana A.; Astrelin, Igor M.

2016-07-01

The effect of precursors on the characteristics of tin oxide obtained by chemical vapor deposition (CVD) method was investigated. The synthesis of nanosized tin(IV) oxide was carried out with the use of two different precursors: tin(II) oxalate obtained using tin chloride(II) and oxalic acid; tin(II) oxalate obtained using tin chloride(II); and ammonium oxalate. The synthesized tin(IV) oxide samples were studied by electron microscopy, X-ray diffraction and optical spectra. The lattice parameters of tin(IV) oxide samples were defined, the bandgap of samples were calculated.

Carbon/tin oxide composite electrodes for improved lithium-ion batteries

DOE PAGES

Li, Yunchao; Levine, Alan M.; Zhang, Jinshui; ...

2018-05-17

Tin and tin oxide-based electrodes are promising high-capacity anodes for lithium-ion batteries. However, poor capacity retention is the major issue with these materials due to the large volumetric expansion that occurs when lithium is alloyed with tin during lithiation and delithiation process. Here, a method to prepare a low-cost, scalable carbon and tin(II) oxide composite anode is reported. The composite material was prepared by ball milling of carbon recovered from used tire powders with 25 wt% tin(II) oxide to form lithium-ion battery anode. With the impact of energy from the ball milling, tin oxide powders were uniformly distributed inside themore » pores of waste-tire-derived carbon. During lithiation and delithiation, the carbon matrix can effectively absorb the volume expansion caused by tin, thereby minimizing pulverization and capacity fade of the electrodes. In conclusion, the as-synthesized anode yielded a capacity of 690 mAh g –1 after 300 cycles at a current density of 40 mA g –1 with a stable battery performance.« less

Carbon/tin oxide composite electrodes for improved lithium-ion batteries

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

Li, Yunchao; Levine, Alan M.; Zhang, Jinshui

Tin and tin oxide-based electrodes are promising high-capacity anodes for lithium-ion batteries. However, poor capacity retention is the major issue with these materials due to the large volumetric expansion that occurs when lithium is alloyed with tin during lithiation and delithiation process. Here, a method to prepare a low-cost, scalable carbon and tin(II) oxide composite anode is reported. The composite material was prepared by ball milling of carbon recovered from used tire powders with 25 wt% tin(II) oxide to form lithium-ion battery anode. With the impact of energy from the ball milling, tin oxide powders were uniformly distributed inside themore » pores of waste-tire-derived carbon. During lithiation and delithiation, the carbon matrix can effectively absorb the volume expansion caused by tin, thereby minimizing pulverization and capacity fade of the electrodes. In conclusion, the as-synthesized anode yielded a capacity of 690 mAh g –1 after 300 cycles at a current density of 40 mA g –1 with a stable battery performance.« less

Effect of pretreatment on a platinized tin oxide catalyst used for low-temperature CO-oxidation

NASA Technical Reports Server (NTRS)

Drawdy, Jean E.; Hoflund, Gar B.; Gardner, Steven D.; Yngvadottir, Eva; Schryer, David R.

1990-01-01

A commercial platinized tin oxide catalyst used for low-temperature CO oxidation has been characterized using ion scattering spectroscopy (ISS), Auger electron spectroscopy (AES) and Electron Spectroscopy for Chemical Analysis (ESCA) before and after reduction in 40 Torr of CO for 1 hour at various temperatures from 75 to 175 C. The reduction results in loss of surface oxygen, formation of metallic tin, conversion of platinum oxides to Pt-O-Sn and Pt(OH)2 and a small amount of metallic Pt which alloys with the tin. These results should be useful in understanding how the pretreatment temperature affects the catalytic activity of platinized tin oxide toward CO oxidation.

Radiation-induced deposition of transparent conductive tin oxide coatings

NASA Astrophysics Data System (ADS)

Umnov, S.; Asainov, O.; Temenkov, V.

2016-04-01

The study of tin oxide films is stimulated by the search for an alternative replacement of indium-tin oxide (ITO) films used as transparent conductors, oxidation catalysts, material gas sensors, etc. This work was aimed at studying the influence of argon ions irradiation on optical and electrical characteristics of tin oxide films. Thin films of tin oxide (without dopants) were deposited on glass substrates at room temperature using reactive magnetron sputtering. After deposition, the films were irradiated with an argon ion beam. The current density of the beam was (were) 2.5 mA/cm2, and the particles energy was 300-400 eV. The change of the optical and electrical properties of the films depending on the irradiation time was studied. Films optical properties were investigated by photometry in the range of 300-1100 nm. Films structural properties were studied using X-ray diffraction. The diffractometric research showed that the films, deposited on a substrate, had a crystal structure, and after argon ions irradiation they became quasi-crystalline (amorphous). It has been found that the transmission increases proportionally with the irradiation time, however the sheet resistance increases disproportionally. Tin oxide films (thickness ~30 nm) with ~100% transmittance and sheet resistance of ~100 kOhm/sq. were obtained. The study has proved to be prospective in the use of ion beams to improve the properties of transparent conducting oxides.

A review of tin oxide-based catalytic systems: Preparation, characterization and catalytic behavior

NASA Technical Reports Server (NTRS)

Hoflund, Gar B.

1987-01-01

This paper reviews the important aspects of the preparation, characterization and catalytic behavior of tin oxide-based catalytic systems including doped tin oxide, mixed oxides which contain tin oxide, Pt supported on tin oxide and Pt/Sn supported on alumina. These systems have a broad range of applications and are continually increasing in importance. However, due to their complex nature, much remains to be understood concerning how they function catalytically.

Tin-gallium-oxide-based UV-C detectors

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Partha; Toporkov, Mykyta; Schoenfeld, Winston V.

2018-02-01

The emergence of conductive gallium oxide single crystal substrates offers the potential for vertical Schottky detectors operating in the UV-C spectral region. We report here on our recent work in the development of Tin Gallium oxide (TGO) thin film metal-semiconductor-metal (MSM) and Schottky detectors using plasma-assisted molecular beam epitaxy on c plane sapphire and bulk Ga2O3 substrates. Tin alloying of gallium oxide thin films was found to systematically reduce the optical band gap of the compound, providing tunability in the UV-C spectral region. Tin concentration in the TGO epilayers was found to be highly dependent on growth conditions, and Ga flux in particular. First attempts to demonstrate vertical Schottky photodetectors using TGO epilayers on bulk n-type Ga2O3 substrates were successful. Resultant devices showed strong photoresponse to UV-C light with peak responsivities clearly red shifted in comparison to Ga2O3 homoepitaxial Schottky detectors due to TGO alloying.

Process for making a noble metal on tin oxide catalyst

NASA Technical Reports Server (NTRS)

Upchurch, Billy T. (Inventor); Davis, Patricia (Inventor); Miller, Irvin M. (Inventor)

1989-01-01

A quantity of reagent grade tin metal or compound, chloride-free, and high-surface-area silica spheres are placed in deionized water, followed by deaerating the mixture by boiling and adding an oxidizing agent, such as nitric acid. The nitric acid oxidizes the tin to metastannic acid which coats the spheres because the acid is absorbed on the substrate. The metastannic acid becomes tin oxide upon drying and calcining. The tin-oxide coated silica spheres are then placed in water and boiled. A chloride-free precious metal compound in aqueous solution is then added to the mixture containing the spheres, and the precious metal compound is reduced to a precious metal by use of a suitable reducing agent such as formic acid. Very beneficial results were obtained using the precious metal compound tetraammine platinum(II) hydroxide.

Morphology and phase transformations of tin oxide nanostructures synthesized by the hydrothermal method in the presence of dicarboxylic acids

NASA Astrophysics Data System (ADS)

Zima, Tatyana.; Bataev, Ivan

2016-11-01

A new approach to the synthesis of non-stoichiometric tin oxide structures with different morphologies and the phase compositions has been evaluated. The nanostructures were synthesized by hydrothermal treatment of the mixtures of dicarboxylic acids ― aminoterephthalic or oxalic ― with nanocrystalline SnO2 powder, which was obtained via the sol-gel technology. The products were characterized by Raman and IR spectroscopy, SEM, HRTEM, and XRD analysis. It was shown that the controlled addition of a dicarboxylic acid leads not only to a change in the morphology of the nanostructures, but also to SnO2-SnO2/Sn3O4-Sn3O4-SnO phase transformations. A single-phase Sn3O4 in the form of the well-separated hexagonal nanoplates and mixed SnO2/Sn3O4 phases in the form of hierarchical flower-like structures were obtained in the presence of organic additives. The effects of concentration, redox activity of the acids and heat treatment on the basic characteristics of the synthesized tin oxide nanostructures and phase transformations in the synthesized materials are discussed.

Vacancy-like defects in nanocrystalline SnO2: influence of the annealing treatment under different atmospheres

NASA Astrophysics Data System (ADS)

Macchi, C.; Ponce, M. A.; Desimone, P. M.; Aldao, C. M.; Somoza, A.

2018-03-01

The study of electronic and chemical properties of semiconductor oxides is motivated by their several applications. In particular, tin oxide is widely used as a solid state gas sensor material. In this regard, the defect structure has been proposed to be crucial in determining the resulting film conductivity and then its sensitivity. Here, the characteristics of vacancy-like defects in nanocrystalline commercial high-purity tin oxide powders and the influence of the annealing treatment under different atmospheres are presented. Specifically, SnO2 nanopowders were annealed at 330 °C under three different types of atmospheres: inert (vacuum), oxidative (oxygen) and reductive (hydrogen). The obtained experimental results are discussed in terms of the vacancy-like defects detected, shedding light to the basic conduction mechanisms, which are responsible for gas detection.

Tin oxide nanosheet assembly for hydrophobic/hydrophilic coating and cancer sensing.

PubMed

Masuda, Yoshitake; Ohji, Tatsuki; Kato, Kazumi

2012-03-01

Tin oxide nanosheets were crystallized on transparent conductive oxide substrates of fluorine-doped tin oxide in aqueous solutions. The nanosheets had chemical ratio of Sn:O:F = 1:1.85:0.076, suggesting fluorine doping into SnO(2). They were hydrophobic surfaces with contact angle of 140°. They were converted to hydrophilic surfaces with contact angle of below 1° by light irradiation. The simple water process will be applied to surface coating of polymers, metals, biomaterials, papers, etc. Furthermore, the tin oxide nanosheets were modified with dye-labeled monoclonal antibody. Monoclonal antibody reacts with human alpha-fetoprotein in blood serum of hepatocellular cancer patient. Photoluminescence and photocurrent were obtained from the nanosheets under excitation light. Photoelectric conversion was an essence in the sensing system. The tin oxide nanosheets with dye-labeled prostate specific antigen will be used for electrodes of prostate cancer sensors. © 2012 American Chemical Society

Effects of oxide distributed in grain boundaries on microstructure stability of nanocrystalline metals

NASA Astrophysics Data System (ADS)

Zhou, Kai; Li, Hui; Biao Pang, Jin; Wang, Zhu

2013-06-01

Nanocrystalline copper and zinc prepared by high-pressure compaction method have been studied by positron lifetime spectroscopy associated with X-ray diffraction. For nanocrystalline Cu, mean grain sizes of the samples decrease after being annealed at 900 °C and increase during aging at 180 °C, revealing that the atoms exchange between the two regions. The positron lifetime results indicate that the vacancy clusters formed in the annealing process are unstable and decomposed at the aging time below 6 hours. In addition, the partially oxidized surfaces of the nanoparticles hinder the grain growth during the ageing at 180 °C, and the vacancy clusters inside the disorder regions which are related to Cu2O need longer aging time to decompose. In the case of nanocrystalline Zn, the open volume defect (not larger than divacancy) is dominant according to the high relative intensity for the short positron lifetime (τ1). The oxide (ZnO) inside the grain boundaries has been found having an effect to hinder the decrease of average positron lifetime (τav) during the annealing, which probably indicates that the oxide stabilizes the microstructure of the grain boundaries. For both nanocrystalline copper and zinc, the oxides in grain boundaries enhance the thermal stability of the microstucture, in spite of their different crystal structures. This effect is very important for the nanocrystalline materials using as radiation resistant materials.

Low-temperature sintering behavior of nanocrystalline indium tin oxide prepared from polymer-containing sols

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

Koroesi, Laszlo, E-mail: l.korosi@chem.u-szeged.hu; Papp, Szilvia; Oszko, Albert

2012-04-15

Highlights: Black-Right-Pointing-Pointer The synthesis of ITO powders and thin films from PVP-containing sols is presented. Black-Right-Pointing-Pointer The nano- and microstructures of ITO are more compact when PVP is used. Black-Right-Pointing-Pointer PVP acts both as a steric stabilizer of the sol and as a pre-sintering agent. Black-Right-Pointing-Pointer The PVP-induced enhanced sintering results in ITO with lower electrical resistance. Black-Right-Pointing-Pointer The surface composition of the ITO films is independent of the initial PVP content. -- Abstract: Indium tin hydroxide (ITH) xerogel powders and thin films with different polyvinylpyrrolidone (PVP) contents (0-22%, w/w) were prepared by a classical sol-gel method. To obtain nanocrystallinemore » indium tin oxide (ITO), the ITH xerogels were calcined at 550 Degree-Sign C. The effect of the initial polymer content on the structure of the ITO powders was studied by means of N{sub 2}-sorption measurements, small-angle X-ray scattering (SAXS), transmission and scanning electron microscopy. The N{sub 2}-sorption measurements revealed that the ITO powders obtained contained micropores and both their porosity and specific surface area decreased with increasing PVP content of the ITH xerogels. The SAXS measurements confirmed the enhanced sintering of the particles in the presence of PVP. The calculated mass fractal dimensions of the ITO powders increased significantly, indicating a significant compaction in structure. The pre-sintered structure could be achieved at relatively low temperature, which induced a significant decreasing (three orders of magnitude) in the electrical resistance of the ITO films.« less

Effect of doping of tin on optoelectronic properties of indium oxide: DFT study

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

Tripathi, Madhvendra Nath, E-mail: ommadhav27@gmail.com

2015-06-24

Indium tin oxide is widely used transparent conductor. Experimentally observed that 6% tin doping in indium oxide is suitable for optoelectronic applications and more doping beyond this limit degrades the optoelectronic property. The stoichiometry (In{sub 32-x}Sn{sub x}O{sub 48+x/2}; x=0-6) is taken to understand the change in lattice parameter, electronic structure, and optical property of ITO. It is observed that lattice parameter increases and becomes constant after 6% tin doping that is in good agreement of the experimental observation. The electronic structure calculation shows that the high tin doping in indium oxide adversely affects the dispersive nature of the bottom ofmore » conduction band of pure indium oxide and decreases the carrier mobility. Optical calculations show that transmittance goes down upto 60% for the tin concentration more than 6%. The present paper shows that how more than 6% tin doping in indium oxide adversely affects the optoelectronic property of ITO.« less

Effect of doping of tin on optoelectronic properties of indium oxide: DFT study

NASA Astrophysics Data System (ADS)

Tripathi, Madhvendra Nath

2015-06-01

Indium tin oxide is widely used transparent conductor. Experimentally observed that 6% tin doping in indium oxide is suitable for optoelectronic applications and more doping beyond this limit degrades the optoelectronic property. The stoichiometry (In32-xSnxO48+x/2; x=0-6) is taken to understand the change in lattice parameter, electronic structure, and optical property of ITO. It is observed that lattice parameter increases and becomes constant after 6% tin doping that is in good agreement of the experimental observation. The electronic structure calculation shows that the high tin doping in indium oxide adversely affects the dispersive nature of the bottom of conduction band of pure indium oxide and decreases the carrier mobility. Optical calculations show that transmittance goes down upto 60% for the tin concentration more than 6%. The present paper shows that how more than 6% tin doping in indium oxide adversely affects the optoelectronic property of ITO.

Morphology and Gas-Sensing Properties of Tin Oxide Foams with Dual Pore Structure

NASA Astrophysics Data System (ADS)

Nam, Kyungju; Kim, Hyeong-Gwan; Choi, Hyelim; Park, Hyeji; Kang, Jin Soo; Sung, Yung-Eun; Lee, Hee Chul; Choe, Heeman

2017-06-01

Tin oxide is a commonly used gas-sensing material, which can be applied as an n- or p-type gas sensor. To improve the gas-sensing performance of tin oxide, we successfully synthesized tin oxide foam via an ice-templating or freeze-casting method. The tin oxide foam samples showed different morphological features depending on the major processing parameters, which include sintering temperature, sintering time, and the amount of added powder. Based on scanning electron microscopy images, we could identify dual pore structure of tin oxide foam containing `wall' pores ranging from 5.3 μm to 10.7 μm, as well as smaller secondary pores (a few micrometers in size) on the wall surfaces. Gas-sensing performance tests for the synthesized tin oxide foams reveal a sensitivity of 13.1, a response time of 192 s, and a recovery time of 160 s at an ethanol gas concentration of 60 ppm at 300°C. This is a remarkable result given that it showed p-type semiconductor behavior and was used without the addition of any catalyst.

The effect of reaction temperature on the room temperature ferromagnetic property of sol-gel derived tin oxide nanocrystal

NASA Astrophysics Data System (ADS)

Sakthiraj, K.; Hema, M.; Balachandra Kumar, K.

2018-06-01

In the present study, nanocrystalline tin oxide materials were prepared using sol-gel method with different reaction temperatures (25 °C, 50 °C, 75 °C & 90 °C) and the relation between the room temperature ferromagnetic property of the sample with processing temperature has been analysed. The X-ray diffraction pattern and infrared absorption spectra of the as-prepared samples confirm the purity of the samples. Transmission electron microscopy images visualize the particle size variation with respect to reaction temperature. The photoluminescence spectra of the samples demonstrate that luminescence process in materials is originated due to the electron transition mediated by defect centres. The room temperature ferromagnetic property is observed in all the samples with different amount, which was confirmed using vibrating sample magnetometer measurements. The saturation magnetization value of the as-prepared samples is increased with increasing the reaction temperature. From the photoluminescence & magnetic measurements we accomplished that, more amount of surface defects like oxygen vacancy and tin interstitial are created due to the increase in reaction temperature and it controls the ferromagnetic property of the samples.

Stabilizing Nanocrystalline Oxide Nanofibers at Elevated Temperatures by Coating Nanoscale Surface Amorphous Films.

PubMed

Yao, Lei; Pan, Wei; Luo, Jian; Zhao, Xiaohui; Cheng, Jing; Nishijima, Hiroki

2018-01-10

Nanocrystalline materials often exhibit extraordinary mechanical and physical properties but their applications at elevated temperatures are impaired by the rapid grain growth. Moreover, the grain growth in nanocrystalline oxide nanofibers at high temperatures can occur at hundreds of degrees lower than that would occur in corresponding bulk nanocrystalline materials, which would eventually break the fibers. Herein, by characterizing a model system of scandia-stabilized zirconia using hot-stage in situ scanning transmission electron microscopy, we discover that the enhanced grain growth in nanofibers is initiated at the surface. Subsequently, we demonstrate that coating the fibers with nanometer-thick amorphous alumina layer can enhance their temperature stability by nearly 400 °C via suppressing the surface-initiated grain growth. Such a strategy can be effectively applied to other oxide nanofibers, such as samarium-doped ceria, yttrium-stabilized zirconia, and lanthanum molybdate. The nanocoatings also increase the flexibility of the oxide nanofibers and stabilize the high-temperature phases that have 10 times higher ionic conductivity. This study provides new insights into the surface-initiated grain growth in nanocrystalline oxide nanofibers and develops a facile yet innovative strategy to improve the high-temperature stability of nanofibers for a broad range of applications.

The development of latent fingerprints by zinc oxide and tin oxide nanoparticles prepared by precipitation technique

NASA Astrophysics Data System (ADS)

Luthra, Deepali; Kumar, Sacheen

2018-05-01

Fingerprints are the very important evidence at the crime scene which must be developed clearly with shortest duration of time to solve the case. Metal oxide nanoparticles could be the mean to develop the latent fingerprints. Zinc oxide and Tin Oxide Nanoparticles were prepared by using chemical precipitation technique which were dried and characterized by X-ray diffraction, UV-Visible spectroscopy and FTIR. The size of zinc oxide crystallite was found to be 14.75 nm with minimum reflectance at 360 nm whereas tin oxide have the size of 90 nm and reflectance at minimum level 321 nm. By using these powdered samples on glass, plastic and glossy cardboard, latent fingerprints were developed. Zinc oxide was found to be better candidate than tin oxide for the fingerprint development on all the three types of substrates.

Bandgap-Engineered Zinc-Tin-Oxide Thin Films for Ultraviolet Sensors.

PubMed

Cheng, Tien-Hung; Chang, Sheng-Po; Chang, Shoou-Jinn

2018-07-01

Zinc-tin-oxide thin-film transistors were prepared by radio frequency magnetron co-sputtering, while an identical zinc-tin-oxide thin film was deposited simultaneously on a clear glass substrate to facilitate measurements of the optical properties. When we adjusted the deposition power of ZnO and SnO2, the bandgap of the amorphous thin film was dominated by the deposition power of SnO2. Since the thin-film transistor has obvious absorption in the ultraviolet region owing to the wide bandgap, the drain current increases with the generation of electron-hole pairs. As part of these investigations, a zinc-tin-oxide thin-film transistor has been fabricated that appears to be very promising for ultraviolet applications.

Rare isotope studies involving catalytic oxidation of CO over platinum-tin oxide

NASA Technical Reports Server (NTRS)

Upchurch, Billy T.; Wood, George M., Jr.; Hess, Robert V.; Hoyt, Ronald F.

1987-01-01

Results of studies utilizing normal and rare oxygen isotopes in the catalytic oxidation of carbon monoxide over a platinum-tin oxide catalyst substrate are presented. Chemisorption of labeled carbon monoxide on the catalyst followed by thermal desorption yielded a carbon dioxide product with an oxygen-18 composition consistent with the formation of a carbonate-like intermediate in the chemisorption process. The efficacy of a method developed for the oxygen-18 labeling of the platinum-tin oxide catalyst surface for use in closed cycle pulsed care isotope carbon dioxide lasers is demonstrated for the equivalent of 10 to the 6th power pulses at 10 pulses per second.

Demonstration of high-performance p-type tin oxide thin-film transistors using argon-plasma surface treatments

NASA Astrophysics Data System (ADS)

Bae, Sang-Dae; Kwon, Soo-Hun; Jeong, Hwan-Seok; Kwon, Hyuck-In

2017-07-01

In this work, we investigated the effects of low-temperature argon (Ar)-plasma surface treatments on the physical and chemical structures of p-type tin oxide thin-films and the electrical performance of p-type tin oxide thin-film transistors (TFTs). From the x-ray photoelectron spectroscopy measurement, we found that SnO was the dominant phase in the deposited tin oxide thin-film, and the Ar-plasma treatment partially transformed the tin oxide phase from SnO to SnO2 by oxidation. The resistivity of the tin oxide thin-film increased with the plasma-treatment time because of the reduced hole concentration. In addition, the root-mean-square roughness of the tin oxide thin-film decreased as the plasma-treatment time increased. The p-type oxide TFT with an Ar-plasma-treated tin oxide thin-film exhibited excellent electrical performance with a high current on-off ratio (5.2 × 106) and a low off-current (1.2 × 10-12 A), which demonstrates that the low-temperature Ar-plasma treatment is a simple and effective method for improving the electrical performance of p-type tin oxide TFTs.

Process for Making a Noble Metal on Tin Oxide Catalyst

NASA Technical Reports Server (NTRS)

Davis, Patricia; Miller, Irvin; Upchurch, Billy

2010-01-01

To produce a noble metal-on-metal oxide catalyst on an inert, high-surface-area support material (that functions as a catalyst at approximately room temperature using chloride-free reagents), for use in a carbon dioxide laser, requires two steps: First, a commercially available, inert, high-surface-area support material (silica spheres) is coated with a thin layer of metal oxide, a monolayer equivalent. Very beneficial results have been obtained using nitric acid as an oxidizing agent because it leaves no residue. It is also helpful if the spheres are first deaerated by boiling in water to allow the entire surface to be coated. A metal, such as tin, is then dissolved in the oxidizing agent/support material mixture to yield, in the case of tin, metastannic acid. Although tin has proven especially beneficial for use in a closed-cycle CO2 laser, in general any metal with two valence states, such as most transition metals and antimony, may be used. The metastannic acid will be adsorbed onto the high-surface-area spheres, coating them. Any excess oxidizing agent is then evaporated, and the resulting metastannic acid-coated spheres are dried and calcined, whereby the metastannic acid becomes tin(IV) oxide. The second step is accomplished by preparing an aqueous mixture of the tin(IV) oxide-coated spheres, and a soluble, chloride-free salt of at least one catalyst metal. The catalyst metal may be selected from the group consisting of platinum, palladium, ruthenium, gold, and rhodium, or other platinum group metals. Extremely beneficial results have been obtained using chloride-free salts of platinum, palladium, or a combination thereof, such as tetraammineplatinum (II) hydroxide ([Pt(NH3)4] (OH)2), or tetraammine palladium nitrate ([Pd(NH3)4](NO3)2).

Nature of active tin species and promoting effect of nickle in silica supported tin oxide for dehydrogenation of propane

NASA Astrophysics Data System (ADS)

Wang, Haoren; Wang, Hui; Li, Xiuyi; Li, Chunyi

2017-06-01

Different with Wang et. al.'s study, we found that polymeric Si-O-Sn2+ rather than Ni-Sn alloy and metallic Sn are active species in silica-supported tin oxide catalysts for dehydrogenation of propane. The results showed that high surface area of mesoporous silica brought about high dispersion of tin oxide species, as a result, catalytic activity and stability were both improved. DRUV-vis, XPS, TPR and XRD studies of fresh and reduced catalysts indicated that the deactivation was related to the reduction of active species rather than the coke formation since active tin species cannot maintain its oxidation state at reaction conditions (high temperature and reducing atmosphere). The formed Ni3Sn2 alloy after reduction just functioned as promoter which accelerated the desorption of H2 and regeneration of active site. A synergy effect between active tin species and Ni3Sn2 alloy were observed.

Understanding the gas sensing properties of polypyrrole coated tin oxide nanofiber mats

NASA Astrophysics Data System (ADS)

Bagchi, Sudeshna; Ghanshyam, C.

2017-03-01

Tin oxide-polypyrrole composites have been widely studied for their enhanced sensing performance towards ammonia vapours, but further investigations are required for an understanding of the interaction mechanisms with different target analytes. In this work, polypyrrole coated tin oxide fibers have been synthesized using a two-step approach of electrospinning and vapour phase polymerization for the sensing of ammonia, ethanol, methanol, 2-propanol and acetone vapours. The resistance variation in the presence of these vapours of different nature and concentration is investigated for the determination of sensor response. A decrease in resistance occurred on interaction of tin oxide-polypyrrole with ammonia, as opposed to previous reported works. Partial reduction of polypyrrole due to interfacial interaction with tin oxide has been proposed to explain this behavior. High sensitivity of 7.45 is achieved for 1 ppm ammonia concentration. Furthermore, the sensor exhibited high sensitivity and a faster response towards ethanol vapours although methanol has the highest electron donating capability. The catalytic mechanism has been discussed to explain this interesting behavior. The results reveal that interaction between tin oxide and polypyrrole is crucial to control the predominant sensing mechanism.

Room temperature aerobic oxidation of amines by a nanocrystalline ruthenium oxide pyrochlore nafion composite catalyst.

PubMed

Venkatesan, Shanmuganathan; Kumar, Annamalai Senthil; Lee, Jyh-Fu; Chan, Ting-Shan; Zen, Jyh-Myng

2012-05-14

The aerobic oxidation of primary amines to their respective nitriles has been carried out at room temperature using a highly reusable nanocrystalline ruthenium oxide pyrochlore Nafion composite catalyst (see figure). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structural and optical studies of 100 MeV Au irradiated thin films of tin oxide

NASA Astrophysics Data System (ADS)

Jaiswal, Manoj Kumar; Kanjilal, D.; Kumar, Rajesh

2013-11-01

Thin films of tin(IV) oxide (SnO2) of 100 nm thickness were grown on silicon (1 0 0) matrices by electron beam evaporation deposition technique under high vacuum. The thicknesses of these films were monitored by piezo-sensor attached to the deposition chamber. Nanocrystallinity is achieved in these thin films by 100 MeV Au8+ using 1 pnA current at normal incidence with ion fluences varying from 1 × 1011 ions/cm2 to 5 × 1013 ions/cm2. Swift Heavy Ion beam irradiation was carried out by using 15 UD Pelletron Accelerator at IUAC, New Delhi, India. Optical studies of pristine and ion irradiated thin films were characterized by UV-Visible spectroscopy and Fourier Transform Infrared (FTIR) spectroscopy. Prominent peak at 610 cm-1 in FTIR spectrum confirmed the O-Sn-O bonding of tin(IV) oxide. For Surface topographical studies and grain size calculations, these films were characterized by Atomic Force Microscope (AFM) using Nanoscope III-A. Crystallinity and phase transformation due to irradiation of pristine and irradiated films were characterized by Glancing Angle X-ray Diffraction (GAXRD) using Brucker-D8 advance model. GAXRD results show improvement in crystallinity and phase transformation due to swift heavy ion irradiation. Grain size distribution was verified by AFM and GAXRD results. Swift heavy ion induced modifications in thin films of SnO2 were confirmed by the presence of prominent peaks at 2θ values of 30.65°, 32.045°, 43.94°, 44.96° and 52.36° in GAXRD spectrum.

Efficient photovoltaic heterojunctions of indium tin oxides on silicon

NASA Technical Reports Server (NTRS)

Dubow, J. B.; Sites, J. R.; Burk, D. E.

1976-01-01

Heterojunction diodes of indium tin oxide films sputtered on to p-silicon using ion-beam techniques display significant photovoltaic effects when exposed to sunlight. Galvanomagnetic and optical measurements confirm that the oxide films are highly degenerate transparent semiconductors. At a tin oxide concentration of 10%, an open-circuit voltage of 0.51 V was observed along with a short-circuit current of 32 mA/sq cm, a fill factor of 0.70, and a conversion efficiency of 12%. As the concentration was raised to 70%, the voltage remained steady, the current fell to 27 mA/sq cm, and the fill factor fell to 0.60

Morphology and phase transformations of tin oxide nanostructures synthesized by the hydrothermal method in the presence of dicarboxylic acids

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

Zima, Tatyana, E-mail: zima@solid.nsc.ru; Novosibirsk State Technical University, 20 K. Marx Prospect, Novosibirsk 630092; Bataev, Ivan

A new approach to the synthesis of non-stoichiometric tin oxide structures with different morphologies and the phase compositions has been evaluated. The nanostructures were synthesized by hydrothermal treatment of the mixtures of dicarboxylic acids ― aminoterephthalic or oxalic ― with nanocrystalline SnO{sub 2} powder, which was obtained via the sol-gel technology. The products were characterized by Raman and IR spectroscopy, SEM, HRTEM, and XRD analysis. It was shown that the controlled addition of a dicarboxylic acid leads not only to a change in the morphology of the nanostructures, but also to SnO{sub 2}–SnO{sub 2}/Sn{sub 3}O{sub 4}–Sn{sub 3}O{sub 4}–SnO phase transformations.more » A single-phase Sn{sub 3}O{sub 4} in the form of the well-separated hexagonal nanoplates and mixed SnO{sub 2}/Sn{sub 3}O{sub 4} phases in the form of hierarchical flower-like structures were obtained in the presence of organic additives. The effects of concentration, redox activity of the acids and heat treatment on the basic characteristics of the synthesized tin oxide nanostructures and phase transformations in the synthesized materials are discussed. - Graphical abstract: The controlled addition of aminoterephthalic or oxalic acid leads not only to a change in the morphology of the nanostructures, but also to SnO{sub 2}–SnO{sub 2}/Sn{sub 3}O{sub 4}–Sn{sub 3}O{sub 4}–SnO phase transformations. - Highlights: • A new approach to the synthesis of non-stoichiometric tin oxide structures is studied. • Tin oxide structures are synthesized via hydrothermal method with dicarboxylic acids. • Morphology and phase composition are changed with redox activity and dosage of acid. • The redox activity of acid has an effect on ratio of SnO and SnO{sub 2} in crystal structure. • A pure phase Sn{sub 3}O{sub 4} nanoplates and SnO{sub 2}/Sn{sub 3}O{sub 4} hierarchical structures are formed.« less

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

Fully printable transparent monolithic solid-state dye-sensitized solar cell with mesoscopic indium tin oxide counter electrode.

PubMed

Yang, Ying; Ri, Kwangho; Rong, Yaoguang; Liu, Linfeng; Liu, Tongfa; Hu, Min; Li, Xiong; Han, Hongwei

2014-09-07

We present a new transparent monolithic mesoscopic solid-state dye-sensitized solar cell based on trilamellar films of mesoscopic TiO2 nanocrystalline photoanode, a ZrO2 insulating layer and an indium tin oxide counter electrode (ITO-CE), which were screen-printed layer by layer on a single substrate. When the thickness of the ITO-CE was optimized to 2.1 μm, this very simple and fully printable solid-state DSSC with D102 dye and spiro-OMeTAD hole transport materials presents efficiencies of 1.73% when irradiated from the front side and 1.06% when irradiated from the rear side under a standard simulated sunlight condition (AM 1.5 Global, 100 mW cm(-2)). Higher parameters could be expected with a better transparent mesoscopic counter electrode and hole conductor for the printable monolithic mesoscopic solid-state DSSC.

Post-annealing-free, room temperature processed nanocrystalline indium tin oxide thin films for plastic electronics

NASA Astrophysics Data System (ADS)

Nyoung Jang, Jin; Jong Lee, You; Jang, YunSung; Yun, JangWon; Yi, Seungjun; Hong, MunPyo

2016-06-01

In this study, we confirm that bombardment by high energy negative oxygen ions (NOIs) is the key origin of electro-optical property degradations in indium tin oxide (ITO) thin films formed by conventional plasma sputtering processes. To minimize the bombardment effect of NOIs, which are generated on the surface of the ITO targets and accelerated by the cathode sheath potential on the magnetron sputter gun (MSG), we introduce a magnetic field shielded sputtering (MFSS) system composed of a permanent magnetic array between the MSG and the substrate holder to block the arrival of energetic NOIs. The MFSS processed ITO thin films reveal a novel nanocrystal imbedded polymorphous structure, and present not only superior electro-optical characteristics but also higher gas diffusion barrier properties. To the best of our knowledge, no gas diffusion barrier composed of a single inorganic thin film formed by conventional plasma sputtering processes achieves such a low moisture permeability.

Performance comparison of tin oxide anodes to commercially available dimensionally stable anodes.

PubMed

Watts, Richard J; Finn, Dennis D; Wyeth, Megan S; Teel, Amy L

2008-06-01

Dimensionally stable anodes (DSAs) demonstrate potential for the electrochemical treatment of industrial waste streams and disinfection of effluent. Oxidation by laboratory-prepared tin oxide DSAs was compared with that of commercially available ruthenium oxide, iridium oxide, and mixed metal oxide DSAs, using hexanol as a probe molecule. The performance of the four anodes was similar in two-chamber reactors, in which the anode cell was separated from the cathode cell by a Nafion membrane, which allows transmission of current between the chambers, but not passage of chemical constituents. The anodes were then evaluated in single-cell reactors, which are more representative of potential treatment and disinfection applications. However, in the single-cell reactors, the tin oxide anodes were significantly more effective at oxidation and generated higher quality cyclic voltammograms than the other DSAs. These results suggest that tin oxide anodes have greater potential than the three commercially available DSAs tested for industrial waste stream treatment and effluent disinfection.

Patterning of Indium Tin Oxide Films

NASA Technical Reports Server (NTRS)

Immer, Christopher

2008-01-01

A relatively rapid, economical process has been devised for patterning a thin film of indium tin oxide (ITO) that has been deposited on a polyester film. ITO is a transparent, electrically conductive substance made from a mixture of indium oxide and tin oxide that is commonly used in touch panels, liquid-crystal and plasma display devices, gas sensors, and solar photovoltaic panels. In a typical application, the ITO film must be patterned to form electrodes, current collectors, and the like. Heretofore it has been common practice to pattern an ITO film by means of either a laser ablation process or a photolithography/etching process. The laser ablation process includes the use of expensive equipment to precisely position and focus a laser. The photolithography/etching process is time-consuming. The present process is a variant of the direct toner process an inexpensive but often highly effective process for patterning conductors for printed circuits. Relative to a conventional photolithography/ etching process, this process is simpler, takes less time, and is less expensive. This process involves equipment that costs less than $500 (at 2005 prices) and enables patterning of an ITO film in a process time of less than about a half hour.

Nanostructured antistatic and antireflective thin films made of indium tin oxide and silica over-coat layer

NASA Astrophysics Data System (ADS)

Cho, Young-Sang; Hong, Jeong-Jin; Yang, Seung-Man; Choi, Chul-Jin

2010-08-01

Stable dispersion of colloidal indium tin oxide nanoparticles was prepared by using indium tin oxide nanopowder, organic solvent, and suitable dispersants through attrition process. Various comminution parameters during the attrition step were studied to optimize the process for the stable dispersion of indium tin oxide sol. The transparent and conductive films were fabricated on glass substrate using the indium tin oxide sol by spin coating process. To obtain antireflective function, partially hydrolyzed alkyl silicate was deposited as over-coat layer on the pre-fabricated indium tin oxide film by spin coating technique. This double-layered structure of the nanostructured film was characterized by measuring the surface resistance and reflectance spectrum in the visible wavelength region. The final film structure was enough to satisfy the TCO regulations for EMI shielding purposes.

Thermally evaporated mechanically hard tin oxide thin films for opto-electronic apllications

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

Tripathy, Sumanta K.; Rajeswari, V. P.

2014-01-28

Tungsten doped tin oxide (WTO) and Molybdenum doped tin oxide (MoTO) thin film were deposited on corn glass by thermal evaporation method. The films were annealed at 350°C for one hour. Structural analysis using Xray diffraction data shows both the films are polycrystalline in nature with monoclinic structure of tin oxide, Sn{sub 3}O{sub 4}, corresponding to JCPDS card number 01-078-6064. SEM photograph showed that both the films have spherical grains with size in the range of 20–30 nm. Compositional analysis was carried out using EDS which reveals the presence of Sn, O and the dopant Mo/W only thereby indicating themore » absence of any secondary phase in the films. The films are found to contain nearly 6 wt% of Mo, 8 wt% of W as dopants respectively. The transmission pattern for both the films in the spectral range 200 – 2000 nm shows that W doping gives a transparency of nearly 80% from 380 nm onwards while Mo doping has less transparency of 39% at 380nm. Film hardness measurement using Triboscope shows a film hardness of about 9–10 GPa for both the films. It indicates that W or M doping in tin oxide provides the films the added advantage of withstanding the mechanical wear and tear due to environmental fluctuations By optimizing the optical and electrical properties, W/Mo doped tin oxide films may be explored as window layers in opto-electronic applications such as solar cells.« less

Growth behavior and properties of atomic layer deposited tin oxide on silicon from novel tin(II)acetylacetonate precursor and ozone

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

Kannan Selvaraj, Sathees; Feinerman, Alan; Takoudis, Christos G., E-mail: takoudis@uic.edu

In this work, a novel liquid tin(II) precursor, tin(II)acetylacetonate [Sn(acac){sub 2}], was used to deposit tin oxide films on Si(100) substrate, using a custom-built hot wall atomic layer deposition (ALD) reactor. Three different oxidizers, water, oxygen, and ozone, were tried. Resulting growth rates were studied as a function of precursor dosage, oxidizer dosage, reactor temperature, and number of ALD cycles. The film growth rate was found to be 0.1 ± 0.01 nm/cycle within the wide ALD temperature window of 175–300 °C using ozone; no film growth was observed with water or oxygen. Characterization methods were used to study the composition, interface quality, crystallinity, microstructure,more » refractive index, surface morphology, and resistivity of the resulting films. X-ray photoelectron spectra showed the formation of a clean SnO{sub x}–Si interface. The resistivity of the SnO{sub x} films was calculated to be 0.3 Ω cm. Results of this work demonstrate the possibility of introducing Sn(acac){sub 2} as tin precursor to deposit conducting ALD SnO{sub x} thin films on a silicon surface, with clean interface and no formation of undesired SiO{sub 2} or other interfacial reaction products, for transparent conducting oxide applications.« less

Oxidation resistant nanocrystalline MCrAl(Y) coatings and methods of forming such coatings

DOEpatents

Cheruvu, Narayana S.; Wei, Ronghua

2014-07-29

The present disclosure relates to an oxidation resistant nanocrystalline coating and a method of forming an oxidation resistant nanocrystalline coating. An oxidation resistant coating comprising an MCrAl(Y) alloy may be deposited on a substrate, wherein M, includes iron, nickel, cobalt, or combinations thereof present greater than 50 wt % of the MCrAl(Y) alloy, chromium is present in the range of 15 wt % to 30 wt % of the MCrAl(Y) alloy, aluminum is present in the range of 6 wt % to 12 wt % of the MCrAl(Y) alloy and yttrium, is optionally present in the range of 0.1 wt % to 0.5 wt % of the MCrAl(Y) alloy. In addition, the coating may exhibit a grain size of 200 nm or less as deposited.

Surface grafting of reduced graphene oxide using nanocrystalline cellulose via click reaction

NASA Astrophysics Data System (ADS)

Kabiri, Roya; Namazi, Hassan

2014-07-01

Reduced graphene oxide (RGO) sheet was functionalized with nanocrystalline cellulose (NCC) via click coupling between azide-functionalized graphene oxide (GO-N3) and terminal propargyl-functionalized nanocrystalline cellulose (PG-NCC). First, the reactive azide groups were introduced on the surface of GO with azidation of 2-chloroethyl isocyanate-treated graphene oxide (GO-Cl). Then, the resulted compounds were reacted with PG-NCC utilizing copper-catalyzed azide-alkyne cycloaddition. During the click reaction, GO was simultaneously reduced to graphene. The coupling was confirmed by Fourier transform infrared, Raman, DEPT135, and 13C NMR spectroscopy, and the complete exfoliation of graphene in the NCC matrix was confirmed with X-ray diffraction measurement. The degree of functionalization from the gradual mass loss of RGO-NCC suggests that around 23 mass % has been functionalized covalently. The size of both NCC and GO was found to be in nanometric range, which decreased after click reaction.

Formation of crack-free nanoporous tin oxide layers via simple one-step anodic oxidation in NaOH at low applied voltages

NASA Astrophysics Data System (ADS)

Zaraska, Leszek; Gilek, Dominika; Gawlak, Karolina; Jaskuła, Marian; Sulka, Grzegorz D.

2016-12-01

A simple anodic oxidation of metallic tin in fluoride-free alkaline electrolyte at low potentials was proposed as a new and effective strategy for fabrication of crack-free nanoporous tin oxide layers. A low-purity Sn foil (98.8%) was used as a starting material, and a series of anodizations were performed in 1 M NaOH at different conditions such as anodizing potential, and duration of the process. It was proved for the first time that nanostructured tin oxides with ultra-small nanochannels having diameters of <15 nm can be synthesized by simple anodization of metallic tin at a potential of 2 V in 1 M NaOH electrolyte. Increasing anodizing potential to 3 and 4 V allowed for formation of tin oxide layers with much larger pores (40-50 nm in diameter) which were still free from internal cracks and transversal pores. Applying such low potentials significantly reduces the oxide growth rate and suppresses vigorous oxygen evolution at the anode. As a result mechanical deterioration of the oxide structure is prevented while strongly alkaline electrolyte is responsible for formation of the porous layer with completely open pores even at such low potentials. On the contrary, when anodization was carried out at potentials of 5 and 6 V, much faster formation of anodic layer, accompanied by vigorous oxygen gas formation, was observed. In consequence, as grown oxide layers exhibited typical cracked or even stacked internal structure. Finally, we demonstrated for the first time that nanoporous tin oxide layers with segments of different channel sizes can be successfully obtained by simple altering potential during anodization.

Synthesis of nanocrystalline rare earth oxides by glycothermal method

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

Hosokawa, Saburo; Iwamoto, Shinji; Inoue, Masashi

2008-11-03

The reaction of yttrium acetate hydrate in 1,2-propanediol at 300 deg. C yielded a product containing acetate groups and glycol moieties. From this product, Y{sub 2}O{sub 3} was directly crystallized at 400 deg. C without the formation of a carbonate oxide phase. The thus-obtained Y{sub 2}O{sub 3} samples had a small crystallite size (2.2 nm) and significantly large surface area (280 m{sup 2}/g). Other nanocrystalline rare earth (Gd-Yb) oxides were also obtained by this method.

On-line coating of glass with tin oxide by atmospheric pressure chemical vapor deposition.

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

Allendorf, Mark D.; Sopko, J.F.; Houf, William G.

2006-11-01

Atmospheric pressure chemical vapor deposition (APCVD) of tin oxide is a very important manufacturing technique used in the production of low-emissivity glass. It is also the primary method used to provide wear-resistant coatings on glass containers. The complexity of these systems, which involve chemical reactions in both the gas phase and on the deposition surface, as well as complex fluid dynamics, makes process optimization and design of new coating reactors a very difficult task. In 2001 the U.S. Dept. of Energy Industrial Technologies Program Glass Industry of the Future Team funded a project to address the need for more accuratemore » data concerning the tin oxide APCVD process. This report presents a case study of on-line APCVD using organometallic precursors, which are the primary reactants used in industrial coating processes. Research staff at Sandia National Laboratories in Livermore, CA, and the PPG Industries Glass Technology Center in Pittsburgh, PA collaborated to produce this work. In this report, we describe a detailed investigation of the factors controlling the growth of tin oxide films. The report begins with a discussion of the basic elements of the deposition chemistry, including gas-phase thermochemistry of tin species and mechanisms of chemical reactions involved in the decomposition of tin precursors. These results provide the basis for experimental investigations in which tin oxide growth rates were measured as a function of all major process variables. The experiments focused on growth from monobutyltintrichloride (MBTC) since this is one of the two primary precursors used industrially. There are almost no reliable growth-rate data available for this precursor. Robust models describing the growth rate as a function of these variables are derived from modeling of these data. Finally, the results are used to conduct computational fluid dynamic simulations of both pilot- and full-scale coating reactors. As a result, general conclusions

First-principles analysis of structural and opto-electronic properties of indium tin oxide

NASA Astrophysics Data System (ADS)

Tripathi, Madhvendra Nath; Shida, Kazuhito; Sahara, Ryoji; Mizuseki, Hiroshi; Kawazoe, Yoshiyuki

2012-05-01

Density functional theory (DFT) and DFT + U (DFT with on-site Coulomb repulsion corrections) calculations have been carried out to study the structural and opto-electronic properties of indium tin oxide (ITO) for both the oxidized and reduced environment conditions. Some of the results obtained by DFT calculations differ from the experimental observations, such as uncertain indication for the site preference of tin atom to replace indium atom at b-site or d-site, underestimation of local inward relaxation in the first oxygen polyhedra around tin atom, and also the improper estimation of electronic density of states and hence resulting in an inappropriate optical spectra of ITO. These discrepancies of theoretical outcomes with experimental observations in ITO arise mainly due to the underestimation of the cationic 4d levels within standard DFT calculations. Henceforth, the inclusion of on-site corrections within DFT + U framework significantly modifies the theoretical results in better agreement to the experimental observations. Within this framework, our calculations show that the indium b-site is preferential site over d-site for tin atom substitution in indium oxide under both the oxidized and reduced conditions. Moreover, the calculated average inward relaxation value of 0.16 Å around tin atom is in good agreement with the experimental value of 0.18 Å. Furthermore, DFT + U significantly modify the electronic structure and consequently induce modifications in the calculated optical spectra of ITO.

Fabrication of heterojunction solar cells by improved tin oxide deposition on insulating layer

DOEpatents

Feng, Tom; Ghosh, Amal K.

1980-01-01

Highly efficient tin oxide-silicon heterojunction solar cells are prepared by heating a silicon substrate, having an insulating layer thereon, to provide a substrate temperature in the range of about 300.degree. C. to about 400.degree. C. and thereafter spraying the so-heated substrate with a solution of tin tetrachloride in a organic ester boiling below about 250.degree. C. Preferably the insulating layer is naturally grown silicon oxide layer.

Influence of silicon oxide on the performance of TiN bottom electrode in phase change memory

NASA Astrophysics Data System (ADS)

Gao, Dan; Liu, Bo; Xu, Zhen; Wang, Heng; Xia, Yangyang; Wang, Lei; Zhu, Nanfei; Li, Ying; Zhan, Yipeng; Song, Zhitang; Feng, Songlin

2016-10-01

The stability of TiN which is the preferred bottom electrode contact (BEC) of phase change memory (PCM) due to its low thermal conductivity and suitable electrical conductivity, is very essential to the reliability of PCM devices. In this work, in order to investigate the effect of high aspect ratio process (HARP) SiO2 on the performance of TiN, both TiN/SiO2, TiN/SiN thin films and TiN BEC device structures are analyzed. By combining transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS), we found that the TiN would be oxidized after the deposition of HARP SiO2 and there exist a thin ( 4 nm) oxidation interfacial layer between TiN and SiO2. Electrical measurements were performed on the 1R PCM test-key die with 7 nm and 10 nm BEC-only cells. The statistical initial resistances of BEC have wide distribution and it is confirmed that the non-uniform oxidation of TiN BEC affects the astringency of the resistance of TiN BEC. The experimental results help to optimize the process of TiN BEC, and SiN is recommended as a better choice as the linear layer.

Synthesis of antimony-doped tin oxide (ATO) nanoparticles by the nitrate-citrate combustion method

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

Zhang Jianrong; Gao Lian

2004-12-02

Antimony-doped tin oxide (ATO) nanoparticles having rutile structure have been synthesized by the combustion method using citric acid (CA) as fuel and nitrate as an oxidant, the metal sources were granulated tin and Sb{sub 2}O{sub 3}. The influence of citric acid (fuel) to metal ratio on the average crystallite size, specific surface area and morphology of the nanoparticles has been investigated. X-ray diffraction showed the tin ions were reduced to elemental tin during combustion reaction. The average ATO crystallite size increased with the increase of citric acid (fuel). Powder morphology and the comparison of crystallite size and grain size showsmore » that the degree of agglomeration of the powder decreased with an increase of the ratio. The highest specific surface area was 37.5 m{sup 2}/g when the citric acid to tin ratio was about 6.« less

Platinum/Tin Oxide/Silica Gel Catalyst Oxidizes CO

NASA Technical Reports Server (NTRS)

Upchurch, Billy T.; Davis, Patricia P.; Schryer, David R.; Miller, Irvin M.; Brown, David; Van Norman, John D.; Brown, Kenneth G.

1991-01-01

Heterogeneous catalyst of platinum, tin oxide, and silica gel combines small concentrations of laser dissociation products, CO and O2, to form CO22 during long times at ambient temperature. Developed as means to prevent accumulation of these products in sealed CO2 lasers. Effective at ambient operating temperatures and installs directly in laser envelope. Formulated to have very high surface area and to chemisorb controlled quantities of moisture: chemisorbed water contained within and upon its structure, makes it highly active and very longlived so only small quantity needed for long times.

Immune stimulation following dermal exposure to unsintered indium tin oxide

PubMed Central

Brock, Kristie; Anderson, Stacey E.; Lukomska, Ewa; Long, Carrie; Anderson, Katie; Marshall, Nikki; Meade, B. Jean

2015-01-01

In recent years, several types of pulmonary pathology, including alveolar proteinosis, fibrosis, and emphysema, have been reported in workers in the indium industry. To date, there remains no clear understanding of the underlying mechanism(s). Pulmonary toxicity studies in rats and mice have demonstrated the development of mediastinal lymph node hyperplasia and granulomas of mediastinal lymph nodes and bronchus-associated lymphoid tissues following exposure to indium tin oxide. Given the association between exposure to other metals and the development of immune-mediated diseases, these studies were undertaken to begin to investigate the immuno-modulatory potential of unsintered indium tin oxide (uITO) in a mouse model. Using modifications of the local lymph node assay, BALB/c mice (five animals/group) were exposed topically via intact or breached skin or injected intradermally at the base of the ear pinnae with either vehicle or increasing concentrations 2.5–10% uITO (90:10 indium oxide/tin oxide, particle size <50 nm). Dose-responsive increases in lymphocyte proliferation were observed with a calculated EC3 of 4.7% for the intact skin study. Phenotypic analysis of draining lymph node cells following intradermal injection with 5% uITO yielded a profile consistent with a T-cell-mediated response. These studies demonstrate the potential for uITO to induce sensitization and using lymphocyte proliferation as a biomarker of exposure, and demonstrate the potential for uITO to penetrate both intact and breached skin. PMID:24164313

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.

Investigation of buried homojunctions in p-InP formed during sputter deposition of both indium tin oxide and indium oxide

NASA Technical Reports Server (NTRS)

Gessert, T. A.; Li, X.; Wanlass, M. W.; Nelson, A. J.; Coutts, T. J.

1990-01-01

While dc magnetron sputter deposition of indium tin oxide leads to the formation of a buried homojunction in single crystal p-type InP, the mechanism of type conversion of the InP surface is not apparent. In view of the recent achievement of nearly 17-percent global efficiencies for cells fabricated solely by sputter deposition of In2O3, it is presently surmised that tin may not be an essential element in type conversion. A variety of electrical and optical techniques are presently used to evaluate the changes at both indium tin oxide/InP and indium oxide/InP interfaces. Such mechanisms as the passivation of acceptors by hydrogen, and sputter damage, are found to occur simultaneously.

Silicon-based microfabricated tin oxide gas sensor incorporating use of Hall effect measurement

NASA Astrophysics Data System (ADS)

Hammond, Joseph Wilson

2000-10-01

Characterization of a microfabricated sol-gel derived nano-particle tin oxide thin film on a silicon substrate, through simultaneous measurement of conductivity, Hall mobility and electron density, had not been accomplished before this study. Conductivity is a function of carrier density and Hall mobility. Therefore, a full understanding of the sensing mechanism of tin oxide requires knowledge of the sensor conductivity, electron density and Hall mobility. A tin oxide thin film (1100A thick), derived by the sol-gel method, was deposited on a Si/SiO2 substrate by means of spin coating method. The sol-gel method produces films of porous interconnected nano-sized particles and is relatively inexpensive and easy to produce compared to existing methods of tin oxide thin film deposition. A goal of this study was to determine the compatibility of sol-gel derived tin oxide thin films with silicon based microfabrication procedures. It was determined that conductivity sensitivity is strongly dependant on electron density level and shows very weak dependence on Hall mobility. Lack of Hall mobility sensitivity to H2 concentration suggests that conduction is grain control limited. In this regime, in which the grain size (D) is less than twice the characteristic Debye length (LD), a change in reducing gas concentration results in a nearly simultaneous change in carrier density throughout the entire grain, while the Hall mobility remains unchanged. The sensor calcined at 500°C and operated at 250°C showed maximum conductivity sensitivity to H2 in air. The sensor exhibited a high conductivity sensitivity of 10.6 to 100ppm H2 in air with response time of (˜1) minute and recovery time of (˜4) minutes. Images of the thin film surface, obtained by SEM, were used to study the effects of calcination temperature and operating conditions on the tin oxide structure. Sensitivity decreased as average grain size increased from 7.7nm to 14.7nm, with increasing calcination temperature from

Spray deposited gallium doped tin oxide thinfilm for acetone sensor application

NASA Astrophysics Data System (ADS)

Preethi, M. S.; Bharath, S. P.; Bangera, Kasturi V.

2018-04-01

Undoped and gallium doped (1 at.%, 2 at.% and 3 at.%) tin oxide thin films were prepared using spray pyrolysis technique by optimising the deposition conditions such as precursor concentration, substrate temperature and spraying rate. X-ray diffraction analysis revealed formation of tetragonally structured polycrystalline films. The SEM micrographs of Ga doped films showed microstructures. The electrical resistivity of the doped films was found to be more than that of the undoped films. The Ga-doped tin oxide thin films were characterised for gas sensors. 1 at.% Ga doped thin films were found to be better acetone gas sensor, showed 68% sensitivity at 350°C temperature.

Pretreatment of Platinum/Tin Oxide-Catalyst

NASA Technical Reports Server (NTRS)

Hess, Robert V.; Paulin, Patricia A.; Miller, Irvin M.; Schryer, David R.; Sidney, Barry D.; Wood, George M.; Upchurch, Billy T.; Brown, Kenneth G.

1987-01-01

Addition of CO to He pretreatment doubles catalytic activity. In sealed, high-energy, pulsed CO2 laser, CO and O2 form as decomposition products of CO2 in laser discharge zone. Products must be recombined, because oxygen concentration of more than few tenths of percent causes rapid deterioration of power, ending in unstable operation. Promising low-temperature catalyst for combining CO and O2 is platinum on tin oxide. New development increases activity of catalyst so less needed for recombination process.

Synthesis and characterization of single-crystalline zinc tin oxide nanowires

NASA Astrophysics Data System (ADS)

Shi, Jen-Bin; Wu, Po-Feng; Lin, Hsien-Sheng; Lin, Ya-Ting; Lee, Hsuan-Wei; Kao, Chia-Tze; Liao, Wei-Hsiang; Young, San-Lin

2014-05-01

Crystalline zinc tin oxide (ZTO; zinc oxide with heavy tin doping of 33 at.%) nanowires were first synthesized using the electrodeposition and heat treatment method based on an anodic aluminum oxide (AAO) membrane, which has an average diameter of about 60 nm. According to the field emission scanning electron microscopy (FE-SEM) results, the synthesized ZTO nanowires are highly ordered and have high wire packing densities. The length of ZTO nanowires is about 4 μm, and the aspect ratio is around 67. ZTO nanowires with a Zn/(Zn + Sn) atomic ratio of 0.67 (approximately 2/3) were observed from an energy dispersive spectrometer (EDS). X-ray diffraction (XRD) and corresponding selected area electron diffraction (SAED) patterns demonstrated that the ZTO nanowire is hexagonal single-crystalline. The study of ultraviolet/visible/near-infrared (UV/Vis/NIR) absorption showed that the ZTO nanowire is a wide-band semiconductor with a band gap energy of 3.7 eV.

Synthesis and characterization of single-crystalline zinc tin oxide nanowires.

PubMed

Shi, Jen-Bin; Wu, Po-Feng; Lin, Hsien-Sheng; Lin, Ya-Ting; Lee, Hsuan-Wei; Kao, Chia-Tze; Liao, Wei-Hsiang; Young, San-Lin

2014-01-01

Crystalline zinc tin oxide (ZTO; zinc oxide with heavy tin doping of 33 at.%) nanowires were first synthesized using the electrodeposition and heat treatment method based on an anodic aluminum oxide (AAO) membrane, which has an average diameter of about 60 nm. According to the field emission scanning electron microscopy (FE-SEM) results, the synthesized ZTO nanowires are highly ordered and have high wire packing densities. The length of ZTO nanowires is about 4 μm, and the aspect ratio is around 67. ZTO nanowires with a Zn/(Zn + Sn) atomic ratio of 0.67 (approximately 2/3) were observed from an energy dispersive spectrometer (EDS). X-ray diffraction (XRD) and corresponding selected area electron diffraction (SAED) patterns demonstrated that the ZTO nanowire is hexagonal single-crystalline. The study of ultraviolet/visible/near-infrared (UV/Vis/NIR) absorption showed that the ZTO nanowire is a wide-band semiconductor with a band gap energy of 3.7 eV.

Amorphous nickel incorporated tin oxide thin film transistors

NASA Astrophysics Data System (ADS)

Yang, Jianwen; Ren, Jinhua; Lin, Dong; Han, Yanbing; Qu, Mingyue; Pi, Shubin; Fu, Ruofan; Zhang, Qun

2017-09-01

Nickel as a dopant has been proposed to suppress excess carrier concentration in n-type tin oxide based thin film transistors (TFTs). The influences of Ni content on nickel doped tin oxide (TNO) thin films and their corresponding TFTs were investigated with experimental results showing that the TNO thin films are amorphous. Through the comparison of the transfer characteristic curves of the TNO TFTs with different Ni contents, it was observed that Ni doping is useful to improve the performance of SnO2-based TFTs by suppressing the off-state current and shifting the threshold voltage to 0 V. The amorphous TNO TFT with 3.3 at.% Ni content shows optimum performance, with field effect mobility of 8.4 cm2 V-1 s-1, saturation mobility of 6.8 cm2 V-1 s-1, subthreshold swing value of 0.8 V/decade, and an on-off current ratio of 2.1  ×  107. Nevertheless, the bias stress stability of SnO2-based TFTs deteriorate.

Rapid pH change due to bacteriorhodopsin measured with a tin-oxide electrode.

PubMed Central

Robertson, B; Lukashev, E P

1995-01-01

The photocurrent transient generated by bacteriorhodopsin (bR) on a tin-oxide electrode is due to pH change and not to charge displacement as previously assumed. Films of either randomly oriented or highly oriented purple membranes were deposited on transparent electrodes made of tin-oxide-coated glass. The membranes contained either wild-type or D96N-mutant bR. When excited with yellow light through the glass, the bR pumps protons across the membrane. The result is a rapid local pH change as well as a charge displacement. Experiments with these films show that it is the pH change rather than the displacement that produces the current transient. The calibration for the transient pH measurement is given. The sensitivity of a tin-oxide electrode to a transient pH change is very much larger than its sensitivity to a steady-state pH change. PMID:7787036

Structural studies of supported tin catalysts

NASA Astrophysics Data System (ADS)

Nava, Noel; Viveros, Tomás

1999-11-01

Tin oxide was supported on aluminium oxide, titanium oxide, magnesium oxide and silicon oxide, and the resulting interactions between the components in the prepared samples and after reduction were characterized by Mössbauer spectroscopy. It was observed that in the oxide state, tin is present as SnO2 on alumina, magnesia and silica, but on titania tin occupies Ti sites in the structure. After hydrogen treatment at high temperatures, tin is reduced from Sn(4) to Sn(2) on alumina and titania; it is reduced from Sn(4) to Sn(0) on silica, and is practically not reduced on magnesia. These results reveal the degree of interaction between tin and the different supports studied.

Facile Synthesis of Wormhole-Like Mesoporous Tin Oxide via Evaporation-Induced Self-Assembly and the Enhanced Gas-Sensing Properties

NASA Astrophysics Data System (ADS)

Li, Xiaoyu; Peng, Kang; Dou, Yewei; Chen, Jiasheng; Zhang, Yue; An, Gai

2018-01-01

Wormhole-like mesoporous tin oxide was synthesized via a facile evaporation-induced self-assembly (EISA) method, and the gas-sensing properties were evaluated for different target gases. The effect of calcination temperature on gas-sensing properties of mesoporous tin oxide was investigated. The results demonstrate that the mesoporous tin oxide sensor calcined at 400 °C exhibits remarkable selectivity to ethanol vapors comparison with other target gases and has a good performance in the operating temperature and response/recovery time. This might be attributed to their high specific surface area and porous structure, which can provide more active sites and generate more chemisorbed oxygen spices to promote the diffusion and adsorption of gas molecules on the surface of the gas-sensing material. A possible formation mechanism of the mesoporous tin oxide and the enhanced gas-sensing mechanism are proposed. The mesoporous tin oxide shows prospective detecting application in the gas sensor fields.

Atomic layer epitaxy of hematite on indium tin oxide for application in solar energy conversion

DOEpatents

Martinson, Alex B.; Riha, Shannon; Guo, Peijun; Emery, Jonathan D.

2016-07-12

A method to provide an article of manufacture of iron oxide on indium tin oxide for solar energy conversion. An atomic layer epitaxy method is used to deposit an uncommon bixbytite-phase iron (III) oxide (.beta.-Fe.sub.2O.sub.3) which is deposited at low temperatures to provide 99% phase pure .beta.-Fe.sub.2O.sub.3 thin films on indium tin oxide. Subsequent annealing produces pure .alpha.-Fe.sub.2O.sub.3 with well-defined epitaxy via a topotactic transition. These highly crystalline films in the ultra thin film limit enable high efficiency photoelectrochemical chemical water splitting.

A novel precursor system and its application to produce tin doped indium oxide.

PubMed

Veith, M; Bubel, C; Zimmer, M

2011-06-14

A new type of precursor has been developed by molecular design and synthesised to produce tin doped indium oxide (ITO). The precursor consists of a newly developed bimetallic indium tin alkoxide, Me(2)In(O(t)Bu)(3)Sn (Me = CH(3), O(t)Bu = OC(CH(3))(3)), which is in equilibrium with an excess of Me(2)In(O(t)Bu). This quasi single-source precursor is applied in a sol-gel process to produce powders and coatings of ITO using a one-step heat treatment process under an inert atmosphere. The main advantage of this system is the simple heat treatment that leads to the disproportionation of the bivalent Sn(II) precursor into Sn(IV) and metallic tin, resulting in an overall reduced state of the metal in the final tin doped indium oxide (ITO) material, hence avoiding the usually necessary reduction step. Solid state (119)Sn-NMR measurements of powder samples confirm the appearance of Sn(II) in an amorphous gel state and of metallic tin after annealing under nitrogen. The corresponding preparation of ITO coatings by spin coating on glass leads to transparent conductive layers with a high transmittance of visible light and a low electrical resistivity without the necessity of a reduction step.

Resistive switching characteristics of thermally oxidized TiN thin films

NASA Astrophysics Data System (ADS)

Biju, K. P.

2018-04-01

Resistive switching characteristics of thermally oxidized TiN thin films and mechanisms were investigated.XPS results indicates Ti-O content decreases with sputter etching and Ti 2p peak shift towards lower binding energy due to formation of Ti-O-N and Ti-N. Pt/TiO2/TiON/TiN stack exhibits both clockwise switching (CWS) and counter clockwise switching(CCWS) characteristic depending on polarity of the applied voltage. However the transition from CCWS to CWS is irreversible. Two stable switching modes with opposite switching polarity and different electrical characteristics are found to coexist in the same memory cell. Clockwise switching shows filamentary characteristics that lead to faster switching with excellent retention at high temperature. Counter-clockwise switching exhibits homogeneous conduction with slower switching and moderate retention. The field-induced switching in both CCWS and CWS might be due to inhomogeneous defect distribution due to thermal oxidation.

Investigation of TiN thin film oxidation depending on the substrate temperature at vacuum break

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

Piallat, Fabien, E-mail: fabien.piallat@gmail.com; CEA, LETI, Campus Minatec, F-38054 Grenoble; LTM-CNRS, 17 rue des Martyrs, 38054 Grenoble

2016-09-15

Due to the reduction of the thickness of the layers used in the advanced technology nodes, there is a growing importance of the surface phenomena in the definition of the general properties of the materials. One of the least controlled and understood phenomenon is the oxidation of metals after deposition, at the vacuum break. In this study, the influence of the sample temperature at vacuum break on the oxidation level of TiN deposited by metalorganic chemical vapor deposition is investigated. TiN resistivity appears to be lower for samples which underwent vacuum break at high temperature. Using X-ray photoelectron spectrometry analysis,more » this change is correlated to the higher oxidation of the TiN layer. Moreover, angle resolved XPS analysis reveals that higher is the temperature at the vacuum break, higher is the surface oxidation of the sample. This surface oxidation is in turn limiting the diffusion of oxygen in the volume of the layer. Additionally, evolution of TiN layers resistivity was monitored in time and it shows that resistivity increases until a plateau is reached after about 10 days, with the lowest temperature at vacuum break resulting in the highest increase, i.e., the resistivity of the sample released to atmosphere at high temperature increased by a factor 1.7 whereas the resistivity of the sample cooled down under vacuum temperature increased by a factor 2.7.« less

Gas Sensors Based on Tin Oxide Nanoparticles Synthesized from a Mini-Arc Plasma Source

DOE PAGES

Lu, Ganhua; Huebner, Kyle L.; Ocola, Leonidas E.; ...

2006-01-01

Minimore » aturized gas sensors or electronic noses to rapidly detect and differentiate trace amount of chemical agents are extremely attractive. In this paper, we report on the fabrication and characterization of a functional tin oxide nanoparticle gas sensor. Tin oxide nanoparticles are first synthesized using a convenient and low-cost mini-arc plasma source. The nanoparticle size distribution is measured online using a scanning electrical mobility spectrometer (SEMS). The product nanoparticles are analyzed ex-situ by high resolution transmission electron microscopy (HRTEM) for morphology and defects, energy dispersive X-ray (EDX) spectroscopy for elemental composition, electron diffraction for crystal structure, and X-ray photoelectron spectroscopy (XPS) for surface composition. Nonagglomerated rutile tin oxide ( SnO 2 ) nanoparticles as small as a few nm have been produced. Larger particles bear a core-shell structure with a metallic core and an oxide shell. The nanoparticles are then assembled onto an e-beam lithographically patterned interdigitated electrode using electrostatic force to fabricate the gas sensor. The nanoparticle sensor exhibits a fast response and a good sensitivity when exposed to 100 ppm ethanol vapor in air.« less

Synaptic plasticity and oscillation at zinc tin oxide/silver oxide interfaces

NASA Astrophysics Data System (ADS)

Murdoch, Billy J.; McCulloch, Dougal G.; Partridge, James G.

2017-02-01

Short-term plasticity, long-term potentiation, and pulse interval dependent plasticity learning/memory functions have been observed in junctions between amorphous zinc-tin-oxide and silver-oxide. The same junctions exhibited current-controlled negative differential resistance and when connected in an appropriate circuit, they behaved as relaxation oscillators. These oscillators produced voltage pulses suitable for device programming. Transmission electron microscopy, energy dispersive X-ray spectroscopy, and electrical measurements suggest that the characteristics of these junctions arise from Ag+/O- electromigration across a highly resistive interface layer. With memory/learning functions and programming spikes provided in a single device structure, arrays of similar devices could be used to form transistor-free neuromorphic circuits.

Purely electronic mechanism of electrolyte gating of indium tin oxide thin films

DOE PAGES

Leng, X.; Bozovic, I.; Bollinger, A. T.

2016-08-10

Epitaxial indium tin oxide films have been grown on both LaAlO 3 and yttria-stabilized zirconia substrates using RF magnetron sputtering. Electrolyte gating causes a large change in the film resistance that occurs immediately after the gate voltage is applied, and shows no hysteresis during the charging/discharging processes. When two devices are patterned next to one another and the first one gated through an electrolyte, the second one shows no changes in conductance, in contrast to what happens in materials (like tungsten oxide) susceptible to ionic electromigration and intercalation. These findings indicate that electrolyte gating in indium tin oxide triggers amore » pure electronic process (electron depletion or accumulation, depending on the polarity of the gate voltage), with no electrochemical reactions involved. Electron accumulation occurs in a very thin layer near the film surface, which becomes highly conductive. These results contribute to our understanding of the electrolyte gating mechanism in complex oxides and may be relevant for applications of electric double layer transistor devices.« less

Reactivation of a tin oxide-containing catalyst

NASA Technical Reports Server (NTRS)

Brown, Kenneth G. (Inventor); Hess, Robert V. (Inventor); Paulin, Patricia A. (Inventor); Miller, Irvin M. (Inventor); Schryer, David R. (Inventor); Upchurch, Billy T. (Inventor); Sidney, Barry D. (Inventor); Wood, George M. (Inventor)

1989-01-01

A method for the reactivation of a tin oxide-containing catalyst of a CO.sub.2 laser is provided. First, the catalyst is pretreated by a standard procedure. When the catalyst experiences diminished activity during usage, the heated zone surrounding the catalyst is raised to a temperature which is the operating temperature of the laser and 400.degree. C. for approximately one hour. The catalyst is exposed to the same laser gas mixture during this period. The temperature of the heated zone is then lowered to the operating temperature of the CO.sub.2 laser.

Benzene oxidation at diamond electrodes: comparison of microcrystalline and nanocrystalline diamonds.

PubMed

Pleskov, Yu V; Krotova, M D; Elkin, V V; Varnin, V P; Teremetskaya, I G; Saveliev, A V; Ralchenko, V G

2012-08-27

A comparative study of benzene oxidation at boron-doped diamond (BDD) and nitrogenated nanocrystalline diamond (NCD) anodes in 0.5 M K(2)SO(4) aqueous solution is conducted by using cyclic voltammetry and electrochemical impedance spectroscopy. It is shown by measurements of differential capacitance and anodic current that during the benzene oxidation at the BDD electrode, adsorption of a reaction intermediate occurs, which partially blocks the electrode surface and lowers the anodic current. At the NCD electrode, benzene is oxidized concurrently with oxygen evolution, a (quinoid) intermediate being adsorbed at the electrode. The adsorption and the electrode surface blocking are reflected in the impedance-frequency and impedance-potential complex-plane plots. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rapid synthesis of tin oxide nanostructures by microwave-assisted thermal oxidation for sensor applications

NASA Astrophysics Data System (ADS)

Phadungdhitidhada, S.; Ruankham, P.; Gardchareon, A.; Wongratanaphisan, D.; Choopun, S.

2017-09-01

In the present work nanostructures of tin oxides were synthesized by a microwave-assisted thermal oxidation. Tin precursor powder was loaded into a cylindrical quartz tube and further radiated in a microwave oven. The as-synthesized products were characterized by scanning electron microscope, transmission electron microscope, and x-ray diffractometer. The results showed that two different morphologies of SnO2 microwires (MWs) and nanoparticles (NPs) were obtained in one minute of microwave radiation under atmospheric ambient. A few tens of the SnO2 MWs with the length of 10-50 µm were found. Some parts of the MWs were decorated with the SnO2 NPs. However, most of the products were SnO2 NPs with the diameter ranging from 30-200 nm. Preparation under loosely closed system lead to mixed phase SnO-SnO2 NPs with diameter of 30-200 nm. The single-phase of SnO2 could be obtained by mixing the Sn precursor powders with CuO2. The products were mostly found to be SnO2 nanowires (NWs) and MWs. The diameter of SnO2 NWs was less than 50 nm. The SnO2 NPs, MWs, and NWs were in the cassiterite rutile structure phase. The SnO NPs was in the tetragonal structure phase. The growth direction of the SnO2 NWs was observed in (1 1 0) and (2 2 1) direction. The ethanol sensor performance of these tin oxide nanostructures showed that the SnO-SnO2 NPs exhibited extremely high sensitivity. Invited talk at 5th Thailand International Nanotechnology Conference (Nano Thailand-2016), 27-29 November 2016, Nakhon Ratchasima, Thailand.

Alternating current transport and dielectric relaxation of nanocrystalline graphene oxide

NASA Astrophysics Data System (ADS)

Zedan, I. T.; El-Menyawy, E. M.

2018-07-01

Graphene oxide (GO) has been synthesized from natural graphite using modified Hummer's method and is subjected to sonication for 1 h. X-ray diffraction (XRD) showed that the prepared GO has nanocrystalline structure with particle size of about 5 nm and high-resolution transmission electron microscope showed that it had a layered structure. The nanocrystalline GO powder was pressed as a disk and the alternating current (AC) electrical conductivity, σAC, and dielectric properties have been investigated in the frequency range 50Hz-5 MHz and temperature range 298-523K using parallel plate spectroscopic technique. Analysis of σ AC as a function of frequency shows that the relation follows Jonscher's universal law with frequency exponent decreases with increasing temperature in which the correlated barrier hopping model is applicable to describe the behavior. The dielectric constant and dielectric loss are studied as functions of frequency and temperature. The dielectric modulus formalism is used for describing the relaxation process in which the relaxation time and its activation energy were evaluated.

Study of annealing time on sol-gel indium tin oxide films on glass

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

De, A.; Biswas, P.K.; Manara, J.

2007-07-15

Indium and tin salt-based precursors maintaining In:Sn atomic ratio as 90:10 were utilized for the development of sol-gel dip coated indium tin oxide films (ITO) on SiO{sub 2} coated ({approx} 200 nm thickness) soda lime silica glass substrate. The gel films were initially cured in air at {approx} 450 deg. C to obtain oxide films of physical thickness {approx} 250 nm. These were then annealed in 95% Ar-5% H{sub 2} atmosphere at {approx} 500 deg. C. The annealing time was varied from 0.5 h to 5 h. Variation of annealing time did not show any considerable change of transmittance inmore » the visible region. Thermal emissivity ({epsilon} {sub d}, 0.67-0.79) of the films were evaluated from their hemispherical spectral reflectance. These passed through a minima with increasing annealing time as the reflectivity of the films in the mid-IR passed through a maxima. The microstructure of the films revealed systematic growth of the ITO grains. XRD and XPS studies revealed the presence of both In and Sn metals in addition to the metal oxides. The energy dispersive X-ray (EDX) analysis showed little lowering of tin content in the films with increasing annealing time.« less

Initial stage corrosion of nanocrystalline copper particles and thin films

NASA Astrophysics Data System (ADS)

Tao, Weimin

1997-12-01

Corrosion behavior is an important issue in nanocrystalline materials research and development. A very fine grain size is expected to have significant effects on the corrosion resistance of these novel materials. However, both the macroscopic corrosion properties and the corresponding structure evolution during corrosion have not been fully studied. Under such circumstances, conducting fundamental research in this area is important and necessary. In this study, high purity nanocrystalline and coarse-grained copper were selected as our sample material, sodium nitrite aqueous solution at room temperature and air at a high temperature were employed as corrosive environments. The weight loss testing and electrochemical methods were used to obtain the macroscopic corrosion properties, whereas the high resolution transmission electron microscope was employed for the structure analysis. The weight loss tests indicate that the corrosion rate of nanocrystalline copper is about 5 times higher than that of coarse-grained copper at the initial stage of corrosion. The electrochemical measurements show that the corrosion potential of the nanocrystalline copper has a 230 mV negative shift in comparison with that of the coarse-grained copper. The nanocrystalline copper also exhibits a significantly higher exchange current density than the coarse-grained copper. High resolution TEM revealed that the surface structure changes at the initial stage of corrosion. It was found that the first copper oxide layer formed on the surface of nanocrystalline copper thin film contains a large density of high angle grain boundaries, whereas that formed on the surface of coarse-grained copper shows highly oriented oxide nuclei and appears to show a strong tendency for forming low angle grain boundaries. A correlation between the macroscopic corrosion properties and the structure characteristics is proposed for the nanocrystalline copper based on the concept of the "apparent" exchange current

The chemical and catalytic properties of nanocrystalline metal oxides prepared through modified sol-gel synthesis

NASA Astrophysics Data System (ADS)

Carnes, Corrie Leigh

The goal of this research was to synthesize, characterize and study the chemical properties of nanocrystalline metal oxides. Nanocrystalline (NC) ZnO, CuO, NiO, Al2O3, and the binary Al2O 3/MgO and ZnO/CuO were prepared through modified sol gel methods. These NC metal oxides were studied in comparison to the commercial (CM) metal oxides. The samples were characterized by XRD, TGA, FTIR, BET, and TEM. The NC samples were all accompanied by a significant increase in surface area and decrease in crystallite size. Several chemical reactions were studied to compare the NC samples to the CM samples. One of the reactions involved a high temperature reaction between carbon tetrachloride and the oxide to form carbon dioxide and the corresponding metal chloride. A similar high temperature reaction was conducted between the metal oxide and hydrogen sulfide to form water and the corresponding metal sulfide. A room temperature gas phase adsorption was studied where SO2 was adsorbed onto the oxide. A liquid phase adsorption conducted at room temperature was the destructive adsorption of paraoxon (a toxic insecticide). In all reactions the NC samples exhibited greater activity, destroying or adsorbing a larger amount of the toxins compared to the CM samples. To better study surface area effects catalytic reactions were also studied. The catalysis of methanol was studied over the nanocrystalline ZnO, CuO, NiO, and ZnO/CuO samples in comparison to their commercial counterparts. In most cases the NC samples proved to be more active catalysts, having higher percent conversions and turnover numbers. A second catalytic reaction was also studied, this reaction was investigated to look at the support effects. The catalysis of cyclopropane to propane was studied over Pt and Co catalysts. These catalysts were supported onto NC and CM alumina by impregnation. By observing differences in the catalytic behavior, support effects have become apparent.

Electrochemical fabrication and optical properties of porous tin oxide films with structural colors

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

Cheng, Hua; Shu, Shiwei; Lee, Chris

2014-10-21

Photonic crystals with porous features not only provide the capability to control light but also enable structural colors that are environmentally sensitive. Here, we report a novel kind of tin oxide-based photonic crystal featuring periodically arranged air pores fabricated by the periodic anodization of tin foil. The existence of a photonic band gap in the fabricated structure is verified by its vivid color, and its reflective spectra which are responsive to environmental stimuli. Furthermore, the sample colors (i.e., the photonic band gap positions) can be easily adjusted by manipulating the anodization parameters. The theoretical modeling results of these tin oxidemore » photonic crystals agree well with the reported experimental ones.« less

On Defect Cluster Aggregation and Non-Reducibilty in Tin-Doped Indium Oxide

NASA Astrophysics Data System (ADS)

Warschkow, Oliver; Ellis, Donald E.; Gonzalez, Gabriela; Mason, Thomas O.

2003-03-01

The conductivity of tin-doped indium oxide (ITO), a transparent conductor, is critically dependent on the amount of tin-doping and oxygen partial pressure during preparation and annealing. Frank and Kostlin (Appl. Phys. A 27 (1982) 197-206) rationalized the carrier concentration dependence by postulating the formation of two types of neutral defect clusters at medium tin-doping levels: "Reducible" and "non-reducible" defect clusters; so named to indicate their ability to create carriers under reduction. According to Frank and Kostlin, both are composed of a single oxygen interstitial and two tin atoms substituting for indium, positioned in non-nearest and nearest coordination, respectively. This present work, seeking to distinguish reducible and non-reducible clusters by use of an atomistic model, finds only a weak correlation of oxygen interstitial binding energies with the relative positioning of dopants. Instead, the number of tin-dopants in the vicinity of the interstitial has a much larger effect on how strongly it is bound, a simple consequence of Coulomb interactions. We postulate that oxygen interstitials become non-reducible when clustered with three or more Sn_In. This occurs at higher doping levels as reducible clusters aggregate and share tin atoms. A simple probabilistic model, estimating the average number of clusters so aggregated, provides a qualitatively correct description of the carrier density in reduced ITO as a function of Sn doping level.

Tin induced a-Si crystallization in thin films of Si-Sn alloys

NASA Astrophysics Data System (ADS)

Neimash, V.; Poroshin, V.; Shepeliavyi, P.; Yukhymchuk, V.; Melnyk, V.; Kuzmich, A.; Makara, V.; Goushcha, A. O.

2013-12-01

Effects of tin doping on crystallization of amorphous silicon were studied using Raman scattering, Auger spectroscopy, scanning electron microscopy, and X-ray fluorescence techniques. Formation of silicon nanocrystals (2-4 nm in size) in the amorphous matrix of Si1-xSnx, obtained by physical vapor deposition of the components in vacuum, was observed at temperatures around 300 °C. The aggregate volume of nanocrystals in the deposited film of Si1-xSnx exceeded 60% of the total film volume and correlated well with the tin content. Formation of structures with ˜80% partial volume of the nanocrystalline phase was also demonstrated. Tin-induced crystallization of amorphous silicon occurred only around the clusters of metallic tin, which suggested the crystallization mechanism involving an interfacial molten Si:Sn layer.

Fabrication and characterization of copper oxide (CuO)–gold (Au)–titania (TiO{sub 2}) and copper oxide (CuO)–gold (Au)–indium tin oxide (ITO) nanowire heterostructures

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

Chopra, Nitin, E-mail: nchopra@eng.ua.edu; Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487; Shi, Wenwu

2014-10-15

Nanoscale heterostructures composed of standing copper oxide nanowires decorated with Au nanoparticles and shells of titania and indium tin oxide were fabricated. The fabrication process involved surfactant-free and wet-chemical nucleation of gold nanoparticles on copper oxide nanowires followed by a line-of-sight sputtering of titania or indium tin oxide. The heterostructures were characterized using high resolution electron microscopy, diffraction, and energy dispersive spectroscopy. The interfaces, morphologies, crystallinity, phases, and chemical compositions were analyzed. The process of direct nucleation of gold nanoparticles on copper oxide nanoparticles resulted in low energy interface with aligned lattice for both the components. Coatings of polycrystalline titaniamore » or amorphous indium tin oxide were deposited on standing copper oxide nanowire–gold nanoparticle heterostructures. Self-shadowing effect due to standing nanowire heterostructures was observed for line-of-sight sputter deposition of titania or indium tin oxide coatings. Finally, the heterostructures were studied using Raman spectroscopy and ultraviolet–visible spectroscopy, including band gap energy analysis. Tailing in the band gap energy at longer wavelengths (or lower energies) was observed for the nanowire heterostructures. - Highlights: • Heterostructures comprised of CuO nanowires coated with Au nanoparticles. • Au nanoparticles exhibited nearly flat and low energy interface with nanowire. • Heterostructures were further sputter-coated with oxide shell of TiO{sub 2} or ITO. • The process resulted in coating of polycrystalline TiO{sub 2} and amorphous ITO shell.« less

Hollow tin/chromium whiskers

NASA Astrophysics Data System (ADS)

Cheng, Jing; Vianco, Paul T.; Li, James C. M.

2010-05-01

Tin whiskers have been an engineering challenge for over five decades. The mechanism has not been agreed upon thus far. This experiment aimed to identify a mechanism by applying compressive stresses to a tin film evaporated on silicon substrate with an adhesion layer of chromium in between. A phenomenon was observed in which hollow whiskers grew inside depleted areas. Using focused ion beam, the hollow whiskers were found to contain both tin and chromium. At the bottom of the depleted areas, thin tin/tin oxide film remained over the chromium layer. It indicates that tin transport occurred along the interface between tin and chromium layers.

Electrochemical properties of tin oxide anodes for sodium-ion batteries

NASA Astrophysics Data System (ADS)

Lu, Ying Ching; Ma, Chuze; Alvarado, Judith; Kidera, Takafumi; Dimov, Nikolay; Meng, Ying Shirley; Okada, Shigeto

2015-06-01

Few tin (Sn)-oxide based anode materials have been found to have large reversible capacity for both sodium (Na)-ion and lithium (Li)-ion batteries. Herein, we report the synthesis and electrochemical properties of Sn oxide-based anodes for sodium-ion batteries: SnO, SnO2, and SnO2/C. Among them, SnO is the most suitable anode for Na-ion batteries with less first cycle irreversibility, better cycle life, and lower charge transfer resistance. The energy storage mechanism of the above-mentioned Sn oxides was studied, which suggested that the conversion reaction of the Sn oxide anodes is reversible in Na-ion batteries. The better anode performance of SnO is attributed by the better conductivity.

Structural and electrical characteristics of gallium tin oxide thin films prepared by electron cyclotron resonance-metal organic chemical vapor deposition.

PubMed

Park, Ji Hun; Byun, Dongjin; Lee, Joong Kee

2011-08-01

Gallium tin oxide composite (GTO) thin films were prepared by electron cyclotron resonance-metal organic chemical vapor deposition (ECR-MOCVD). The organometallics of tetramethlytin and trimethylgallium were used for precursors of gallium and tin, respectively. X-ray diffraction (XRD) characterization indicated that the gallium tin oxide composite thin films show the nanopolycrystalline of tetragonal rutile structure. Hall measurement indicated that the Ga/[O+Sn] mole ratio play an important role to determine the electrical properties of gallium tin composite oxide thin films. n-type conducting film obtained Ga/[O+Sn] mole ratio of 0.05 exhibited the lowest electrical resistivity of 1.21 x 10(-3) ohms cm. In our experimental range, the optimized carrier concentration of 3.71 x 10(18) cm(-3) was prepared at the Ga/[O+Sn] mole ratio of 0.35.

Method of making nanocrystalline alpha alumina

DOEpatents

Siegel, Richard W.; Hahn, Horst; Eastman, Jeffrey A.

1992-01-01

Method of making selected phases of nanocrystalline ceramic materials. Various methods of controlling the production of nanocrystalline alpha alumina and titanium oxygen phases are described. Control of the gas atmosphere and use of particular oxidation treatments give rise to the ability to control the particular phases provided in the aluminum/oxygen and titanium/oxygen system.

Positron annihilation and X-ray diffraction studies on tin oxide thin films

NASA Astrophysics Data System (ADS)

Prabakar, K.; Abhaya, S.; Krishnan, R.; Kalavathi, S.; Dash, S.; Jayapandian, J.; Amarendra, G.

2009-04-01

Positron annihilation spectroscopy along with glancing incidence X-ray diffraction have been used to investigate tin oxide thin films grown on Si by pulsed laser deposition. The films were prepared at room temperature and at 670 K under oxygen partial pressure. As-grown samples are amorphous and are found to contain large concentration of open volume sites (vacancy defects). Post-deposition annealing of as-grown samples at 970 K is found to drastically reduce the number of open volume sites and the film becomes crystalline. However, film grown under elevated temperature and under partial pressure of oxygen is found to exhibit a lower S-parameter, indicating lower defect concentration. Based on the analysis of experimental positron annihilation results, the defect-sensitive S-parameter and the overlayer thickness of tin oxide thin films are deduced. S- W correlation plots exhibit distinct positron trapping defect states in three samples.

The Application of Metal Oxide Nanomaterials for Chemical Sensor Development

NASA Technical Reports Server (NTRS)

Xu, Jennifer C.; Hunter, Gary W.; Evans, Laura J.; VanderWal, Randy L.; Berger, Gordon M.

2007-01-01

NASA Glenn Research Center (GRC) has been developing miniature chemical sensors for a variety of applications including fire detection, emissions monitoring, fuel leak detection, and environmental monitoring. Smart Lick and Stick sensor technology which integrates a sensor array, electronics, telemetry, and power into one microsystem are being developed. These microsystems require low power consumption for long-term aerospace applications. One approach to decreasing power consumption is the use of nanotechnology. Nanocrystalline tin oxide (SnO2) carbon monoxide (CO) sensors developed previously by this group have been successfully used for fire detection and emissions monitoring. This presentation will briefly review the overall NASA GRC chemical sensor program and discuss our further effort in nanotechnology applications. New carbon dioxide (CO2) sensing material using doped nanocrystalline SnO2 will be discussed. Nanocrystalline SnO2 coated solid electrolyte CO2 sensors and SnO2 nanorod and nanofiber hydrogen (H2) sensors operated at reduced or room temperatures will also be discussed.

Surface oxidation of tin chalcogenide nanocrystals revealed by 119Sn-Mössbauer spectroscopy.

PubMed

de Kergommeaux, Antoine; Faure-Vincent, Jérôme; Pron, Adam; de Bettignies, Rémi; Malaman, Bernard; Reiss, Peter

2012-07-18

Narrow band gap tin(II) chalcogenide (SnS, SnSe, SnTe) nanocrystals are of high interest for optoelectronic applications such as thin film solar cells or photodetectors. However, charge transfer and charge transport processes strongly depend on nanocrystals' surface quality. Using (119)Sn-Mössbauer spectroscopy, which is the most sensitive tool for probing the Sn oxidation state, we show that SnS nanocrystals exhibit a Sn((IV))/Sn((II)) ratio of around 20:80 before and 40:60 after five minutes exposure to air. Regardless of the tin or sulfur precursors used, similar results are obtained using six different synthesis protocols. The Sn((IV)) content before air exposure arises from surface related SnS(2) and Sn(2)S(3) species as well as from surface Sn atoms bound to oleic acid ligands. The increase of the Sn((IV)) content upon air exposure results from surface oxidation. Full oxidation of the SnS nanocrystals without size change is achieved by annealing at 500 °C in air. With the goal to prevent surface oxidation, SnS nanocrystals are capped with a cadmium-phosphonate complex. A broad photoluminescence signal centered at 600 nm indicates successful capping, which however does not reduce the air sensitivity. Finally we demonstrate that SnSe nanocrystals exhibit a very similar behavior with a Sn((IV))/Sn((II)) ratio of 43:57 after air exposure. In the case of SnTe nanocrystals, the ratio of 55:45 is evidence of a more pronounced tendency for oxidation. These results demonstrate that prior to their use in optoelectronics further surface engineering of tin chalcogenide nanocrystals is required, which otherwise have to be stored and processed under inert atmosphere.

CO2 Sensors Based on Nanocrystalline SnO2 Doped with CuO

NASA Technical Reports Server (NTRS)

Xu, Jennifer C.; Hunter, Gary W.; Liu, Chung Chiun; Ward, Benjamin J.

2008-01-01

Nanocrystalline tin oxide (SnO2) doped with copper oxide (CuO) has been found to be useful as an electrical-resistance sensory material for measuring the concentration of carbon dioxide in air. SnO2 is an n-type semiconductor that has been widely used as a sensing material for detecting such reducing gases as carbon monoxide, some of the nitrogen oxides, and hydrocarbons. Without doping, SnO2 usually does not respond to carbon dioxide and other stable gases. The discovery that the electrical resistance of CuO-doped SnO2 varies significantly with the concentration of CO2 creates opportunities for the development of relatively inexpensive CO2 sensors for detecting fires and monitoring atmospheric conditions. This discovery could also lead to research that could alter fundamental knowledge of SnO2 as a sensing material, perhaps leading to the development of SnO2-based sensing materials for measuring concentrations of oxidizing gases. Prototype CO2 sensors based on CuO-doped SnO2 have been fabricated by means of semiconductor-microfabrication and sol-gel nanomaterial-synthesis batch processes that are amendable to inexpensive implementation in mass production.

Tin Oxide Chemistry from Macquer (1758) to Mendeleeff (1891) as Revealed in the Textbooks and Other Literature of the Era

ERIC Educational Resources Information Center

de Berg, Kevin C.

2008-01-01

Eight chemistry textbooks written from 1758 to 1891 have been analyzed for the way they present the chemistry of the oxides of tin. This analysis gives insight into the foundation of a number of chemical ideas such as nomenclature and composition used in modern chemistry. Four major preparation techniques for the production of tin oxides emerge…

Reactive Ball Milling to Fabricate Nanocrystalline Titanium Nitride Powders and Their Subsequent Consolidation Using SPS

NASA Astrophysics Data System (ADS)

El-Eskandarany, M. Sherif

2017-05-01

The room-temperature reactive ball milling (RBM) approach was employed to synthesize nanostructured fcc-titanium nitride (TiN) powders, starting from milling hcp-titanium (Ti) powders under 10 bar of a nitrogen gas atmosphere, using a roller mill. During the first and intermediate stage of milling, the agglomerated Ti powders were continuously disintegrated into smaller particles with fresh surfaces. Increasing the RBM time led to an increase in the active-fresh surfaces of Ti, resulting increasing of the mole fraction of TiN against unreacted hcp-Ti. Toward the end of the RBM time (20 h), ultrafine spherical powder (with particles 0.5 μm in diameter) of the fcc-TiN phase was obtained, composed of nanocrystalline grains with an average diameter of 8 nm. The samples obtained after different stages of RBM time were consolidated under vacuum at 1600 °C into cylindrical bulk compacts of 20 mm diameter, using spark plasma sintering technique. These compacts that maintained their nanocrystalline characteristics with an average grain size of 56 nm in diameter, possessed high relative density (above 99% of the theoretical density). The Vickers hardness of the as-consolidated TiN was measured and found to be 22.9 GPa. The modulus of elasticity and shear modulus of bulk TiN were measured by a nondestructive test and found to be 384 and 189 GPa, respectively. In addition, the coefficient of friction of the end-product TiN bulk sample was measured and found to be 0.35.

Enhancing the mechanical and biological performance of a metallic biomaterial for orthopedic applications through changes in the surface oxide layer by nanocrystalline surface modification.

PubMed

Bahl, Sumit; Shreyas, P; Trishul, M A; Suwas, Satyam; Chatterjee, Kaushik

2015-05-07

Nanostructured metals are a promising class of biomaterials for application in orthopedics to improve the mechanical performance and biological response for increasing the life of biomedical implants. Surface mechanical attrition treatment (SMAT) is an efficient way of engineering nanocrystalline surfaces on metal substrates. In this work, 316L stainless steel (SS), a widely used orthopedic biomaterial, was subjected to SMAT to generate a nanocrystalline surface. Surface nanocrystallization modified the nature of the oxide layer present on the surface. It increased the corrosion-fatigue strength in saline by 50%. This increase in strength is attributed to a thicker oxide layer, residual compressive stresses, high strength of the surface layer, and lower propensity for intergranular corrosion in the nanocrystalline layer. Nanocrystallization also enhanced osteoblast attachment and proliferation. Intriguingly, wettability and surface roughness, the key parameters widely acknowledged for controlling the cellular response remained unchanged after nanocrystallization. The observed cellular behavior is explained in terms of the changes in electronic properties of the semiconducting passive oxide film present on the surface of 316L SS. Nanocrystallization increased the charge carrier density of the n-type oxide film likely preventing denaturation of the adsorbed cell-adhesive proteins such as fibronectin. In addition, a net positive charge developed on the otherwise neutral oxide layer, which is known to facilitate cellular adhesion. The role of changes in the electronic properties of the oxide films on metal substrates is thus highlighted in this work. This study demonstrates the advantages of nanocrystalline surface modification by SMAT for processing metallic biomaterials used in orthopedic implants.

Multifunctional organized mesoporous tin oxide films templated by graft copolymers for dye-sensitized solar cells.

PubMed

Park, Jung Tae; Ahn, Sung Hoon; Roh, Dong Kyu; Lee, Chang Soo; Kim, Jong Hak

2014-07-01

The synthesis of organized mesoporous SnO2 films with high porosity, larger pores, and good interconnectivity, obtained by sol-gel templating with an amphiphilic graft copolymer, poly(vinyl chloride)-graft-poly(oxyethylene methacrylate), is reported. An improved performance of dye-sensitized solar cells (DSSCs) is demonstrated by the introduction of a 400 nm thick organized mesoporous SnO2 interfacial (om-SnO2 IF) layer between nanocrystalline TiO2 (nc-TiO2 ) and a fluorine-doped tin oxide substrate. To elucidate the improved efficiency, the structural, optical, and electrochemical properties of the devices were characterized by SEM, UV/Vis spectroscopy, noncontact 3D surface profilometry, intensity-modulated photocurrent/voltage spectroscopy, incident photon-to-electron conversion efficiency, and electrochemical impedance spectroscopy measurements. The energy-conversion efficiency of the solid polymerized ionic liquid based DSSC fabricated with the om-SnO2 IF/nc-TiO2 photoanode reached 5.9% at 100 mW cm(-2) ; this is higher than those of neat nc-TiO2 (3.5%) and organized mesoporous TiO2 interfacial/nc-TiO2 layer (5.4%) photoanodes. The improved efficiency is attributed to the antireflective property, cascadal energy band gap, good interconnectivity, and high electrical conductivity of the om-SnO2 IF layer, which results in enhanced light harvesting, increased electron transport, reduced charge recombination, and decreased interfacial/internal resistance. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hybrid structure of biotemplate-zinc-tin oxide for better optical, morphological and photocatalytic properties

NASA Astrophysics Data System (ADS)

Karpuraranjith, M.; Thambidurai, S.

2017-03-01

A new chitosan (as biotemplate)-zinc-tin oxide hybrid structure was successfully synthesized by a chemical precipitation method and annealed at 500 °C. We studied the structural changes, optical, thermal and photo catalytic properties. The chemical bonding of the Zn-O and Sn-O-Sn functional groups were confirmed by FT-IR absorption peaks appearing at 538 and 635 cm-1. The different ratio of ZnO to SnO2 particles on the biotemplate matrix altered the morphology of the hybrids from an agglomerated state to a microcrystalline form confirmed by HR-SEM and TEM analysis. The formation of a Zn0.15Sn0.85O hybrid structure was observed in the visible light region, with an energy band gap of ˜3.19 eV and higher surface area of 98 m2 g-1. The thermal property shows that CS-Zn0.15Sn0.85O has a higher thermal stability than a CS-Zn0.25Sn0.75O hybrid structure. The results demonstrate that the biotemplate-zinc-tin oxide hybrid structure has a reinforced effect compared to the other components. Therefore, a biotemplate-based zinc-tin oxide hybrid structure could be a promising material for better dye removal efficiency, which was obtained for ˜100 and 96% with MB and RY-15 dyes.

Hydrogen plasma treatment for improved conductivity in amorphous aluminum doped zinc tin oxide thin films

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

Morales-Masis, M., E-mail: monica.moralesmasis@epfl.ch; Ding, L.; Dauzou, F.

2014-09-01

Improving the conductivity of earth-abundant transparent conductive oxides (TCOs) remains an important challenge that will facilitate the replacement of indium-based TCOs. Here, we show that a hydrogen (H{sub 2})-plasma post-deposition treatment improves the conductivity of amorphous aluminum-doped zinc tin oxide while retaining its low optical absorption. We found that the H{sub 2}-plasma treatment performed at a substrate temperature of 50 °C reduces the resistivity of the films by 57% and increases the absorptance by only 2%. Additionally, the low substrate temperature delays the known formation of tin particles with the plasma and it allows the application of the process to temperature-sensitivemore » substrates.« less

Nanocrystalline heterojunction materials

DOEpatents

Elder, Scott H.; Su, Yali; Gao, Yufei; Heald, Steve M.

2003-07-15

Mesoporous nanocrystalline titanium dioxide heterojunction materials are disclosed. In one disclosed embodiment, materials comprising a core of titanium dioxide and a shell of a molybdenum oxide exhibit a decrease in their photoadsorption energy as the size of the titanium dioxide core decreases.

Alkaline earth metal doped tin oxide as a novel oxygen storage material

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

Dong, Qiang, E-mail: dong@tagen.tohoku.ac.jp; Yin, Shu; Yoshida, Mizuki

2015-09-15

Alkaline earth metal doped tin oxide (SnO{sub 2}) hollow nanospheres with a diameter of 50 nm have been synthesized successfully via a facial solvothermal route in a very simple system composed of only ethanol, acetic acid, SnCl{sub 4}·5H{sub 2}O and A(NO{sub 3}){sub 2}·xH{sub 2}O (A = Mg, Ca, Sr, Ba). The synthesized undoped SnO{sub 2} and A-doped SnO{sub 2} hollow nanospheres were characterized by the oxygen storage capacity (OSC), X-ray diffraction, transmission electron microscopy and the Brunauer–Emmet–Teller (BET) technique. The OSC values of all samples were measured using thermogravimetric-differential thermal analysis. The incorporation of alkaline earth metal ion into tinmore » oxide greatly enhanced the thermal stability and OSC. Especially, Ba-doped SnO{sub 2} hollow nanospheres calcined at 1000 °C for 20 h with a BET surface area of 61 m{sup 2} g{sup −1} exhibited the considerably high OSC of 457 μmol-O g{sup −1} and good thermal stability. Alkaline earth metal doped tin oxide has the potential to be a novel oxygen storage material.« less

Junction characteristics of indium tin oxide/indium phosphide solar cells

NASA Astrophysics Data System (ADS)

Sheldon, P.; Ahrenkiel, R. K.; Hayes, R. E.; Russell, P. E.; Nottenburg, R. N.; Kazmerski, L. L.

Efficient indium tin oxide (ITO)/p-InP solar cells have been fabricated. Typical uncorrected efficiencies range from 9-12 percent at AM1 intensities. It is shown that deposition of ITO causes a semi-insulating layer at the InP surface as determined by C-V measurements. The thickness of this layer is approximately 750 A. We believe that this high resistivity region is due to surface accumulation of Fe at the ITO/InP interface.

A characterization study of a hydroxylated polycrystalline tin oxide surface

NASA Technical Reports Server (NTRS)

Hoflund, Gar B.; Grogan, Austin L., Jr.; Asbury, Douglas A.; Schryer, David R.

1989-01-01

In this study Auger electron spectroscopy, electron spectroscopy for chemical analysis (ESCA) and electron-stimulated desorption (ESD) have been used to examine a polycrystalline tin oxide surface before and after annealing in vacuum at 500 C. Features due to surface hydroxyl groups are present in both the ESCA and ESD spectra, and ESD shows that several chemical states of hydrogen are present. Annealing at 500 C causes a large reduction in the surface hydrogen concentration but not complete removal.

Antimony-Doped Tin Oxide Thin Films Grown by Home Made Spray Pyrolysis Technique

NASA Astrophysics Data System (ADS)

Yusuf, Gbadebo; Babatola, Babatunde Keji; Ishola, Abdulahi Dimeji; Awodugba, Ayodeji O.; Solar cell Collaboration

2016-03-01

Transparent conducting antimony-doped tin oxide (ATO) films have been deposited on glass substrates by home made spray pyrolysis technique. The structural, electrical and optical properties of the ATO films have been investigated as a function of Sb-doping level and annealing temperature. The optimum target composition for high conductivity and low resistivity was found to be 20 wt. % SnSb2 + 90 wt. ATO. Under optimized deposition conditions of 450oC annealing temperature, electrical resistivity of 5.2×10-4 Ω -cm, sheet resistance of 16.4 Ω/sq, average optical transmittance of 86% in the visible range, and average optical band-gap of 3.34eV were obtained. The film deposited at lower annealing temperature shows a relatively rough, loosely bound slightly porous surface morphology while the film deposited at higher annealing temperature shows uniformly distributed grains of greater size. Keywords: Annealing, Doping, Homemade spray pyrolysis, Tin oxide, Resistivity

Influence of anodizing conditions on generation of internal cracks in anodic porous tin oxide films grown in NaOH electrolyte

NASA Astrophysics Data System (ADS)

Zaraska, Leszek; Gawlak, Karolina; Gurgul, Magdalena; Dziurka, Magdalena; Nowak, Marlena; Gilek, Dominika; Sulka, Grzegorz D.

2018-05-01

Nanoporous tin oxide layers were synthesized via simple one-step anodic oxidation of a low-purity Sn foil (98.8%) in sodium hydroxide electrolyte. The process of pore formation at the early stage of anodization was discussed on the basis of concepts of oxygen bubble mould effect and viscous flow of oxide. The effect of anodizing conditions on the generation of internal cracks and fractures within the anodic film was investigated in detail. It was confirmed that crack-free tin oxide films can be obtained if the anodization is carried out at the potential of 4 V independently of the electrolyte concentration. On the other hand, the porous anodic film with a totally stacked internal morphology is obtained at the potential of 5 V in 0.1 M NaOH electrolyte. The generation of internal cracks and voids can be attributed to a much lower surface porosity and local trapping of O2 inside the pores of the oxide layer. However, increasing electrolyte concentration allows for obtaining less cracked porous films due to effective and uniform liberation of oxygen bubbles from the channels through completely open pore mouths. Furthermore, it was confirmed that uniformity of the anodic tin oxide layers can be significantly improved by vigorous electrolyte stirring. Finally, we observed that the addition of ethanol to the electrolyte can reduce anodic current density and the oxide growth rate. In consequence, less cracked anodic film can be formed even at the potential of 6 V. The generation of oxygen at the pore bottoms, together with the open pore mouths were found to be critical factors responsible for the anodic formation of crack-free porous tin oxide films.

Nanocrystalline Heterojunction Materials

DOEpatents

Elder, Scott H.; Su, Yali; Gao, Yufei; Heald, Steve M.

2004-02-03

Mesoporous nanocrystalline titanium dioxide heterojunction materials and methods of making the same are disclosed. In one disclosed embodiment, materials comprising a core of titanium dioxide and a shell of a molybdenum oxide exhibit a decrease in their photoadsorption energy as the size of the titanium dioxide core decreases.

Investigation of fluorine-doped tin oxide based optically transparent E-shaped patch antenna for terahertz communications

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

Anand, S., E-mail: anand.s.krishna@gmail.com, E-mail: darak.mayur@gmail.com, E-mail: srk@nitt.edu; Darak, Mayur Sudesh, E-mail: anand.s.krishna@gmail.com, E-mail: darak.mayur@gmail.com, E-mail: srk@nitt.edu; Kumar, D. Sriram, E-mail: anand.s.krishna@gmail.com, E-mail: darak.mayur@gmail.com, E-mail: srk@nitt.edu

2014-10-15

In this paper, a fluorine-doped tin oxide based optically transparent E-shaped patch antenna is designed and its radiation performance is analyzed in the 705 – 804 GHz band. As optically transparent antennas can be mounted on optical display, they facilitate the reduction of overall system size. The proposed antenna design is simulated using electromagnetic solver - Ansys HFSS and its characteristics such as impedance bandwidth, directivity, radiation efficiency and gain are observed. Results show that the fluorine-doped tin oxide based optically transparent patch antenna overcomes the conventional patch antenna limitations and thus the same can be used for solar cellmore » antenna used in satellite systems.« less

Energy level alignment at the interfaces between typical electrodes and nucleobases: Al/adenine/indium-tin-oxide and Al/thymine/indium-tin-oxide

NASA Astrophysics Data System (ADS)

Lee, Younjoo; Lee, Hyunbok; Park, Soohyung; Yi, Yeonjin

2012-12-01

We investigated the interfacial electronic structures of Al/adenine/indium-tin-oxide (ITO) and Al/thymine/ITO using in situ ultraviolet and x-ray photoemission spectroscopy and density functional theory calculations. Adenine shows both an interface dipole and level bending, whereas thymine shows only an interface dipole in contact with ITO. In addition, thymine possesses a larger ionization energy than adenine. These are understood with delocalized π states confirmed with theoretical calculations. For the interface between nucleobases and Al, both nucleobases show a prominent reduction of the electron injection barrier from Al to each base in accordance with a downward level shift.

Combustion synthesized indium-tin-oxide (ITO) thin film for source/drain electrodes in all solution-processed oxide thin-film transistors

NASA Astrophysics Data System (ADS)

Tue, Phan Trong; Inoue, Satoshi; Takamura, Yuzuru; Shimoda, Tatsuya

2016-06-01

We report combustion solution synthesized (SCS) indium-tin-oxide (ITO) thin film, which is a well-known transparent conductive oxide, for source/drain (S/D) electrodes in solution-processed amorphous zirconium-indium-zinc-oxide TFT. A redox-based combustion synthetic approach is applied to ITO thin film using acetylacetone as a fuel and metal nitrate as oxidizer. The structural and electrical properties of SCS-ITO precursor solution and thin films were systematically investigated with changes in tin concentration, indium metal precursors, and annealing conditions such as temperature, time, and ambient. It was found that at optimal conditions the SCS-ITO thin film exhibited high crystalline quality, atomically smooth surface (RMS ~ 4.1 Å), and low electrical resistivity (4.2 × 10-4 Ω cm). The TFT using SCS-ITO film as the S/D electrodes showed excellent electrical properties with negligible hysteresis. The obtained "on/off" current ratio, subthreshold swing factor, subthreshold voltage, and field-effect mobility were 5 × 107, 0.43 V/decade, 0.7 V, and 2.1 cm2/V s, respectively. The performance and stability of the SCS-ITO TFT are comparable to those of the sputtered-ITO TFT, emphasizing that the SCS-ITO film is a promising candidate for totally solution-processed oxide TFTs.

Transparent and Flexible Zinc Tin Oxide Thin Film Transistors and Inverters using Low-pressure Oxygen Annealing Process

NASA Astrophysics Data System (ADS)

Lee, Kimoon; Kim, Yong-Hoon; Kim, Jiwan; Oh, Min Suk

2018-05-01

We report on the transparent and flexible enhancement-load inverters which consist of zinc tin oxide (ZTO) thin film transistors (TFTs) fabricated at low process temperature. To control the electrical characteristics of oxide TFTs by oxygen vacancies, we applied low-pressure oxygen rapid thermal annealing (RTA) process to our devices. When we annealed the ZTO TFTs in oxygen ambient of 2 Torr, they showed better electrical characteristics than those of the devices annealed in the air ambient of 760 Torr. To realize oxide thin film transistor and simple inverter circuits on flexible substrate, we annealed the devices in O2 of 2 Torr at 150° C and could achieve the decent electrical properties. When we used transparent conductive oxide electrodes such as indium zinc oxide (IZO) and indium tin oxide (ITO), our transparent and flexible inverter showed the total transmittance of 68% in the visible range and the voltage gain of 5. And the transition voltage in voltage transfer curve was located well within the range of operation voltage.

Optoelectric biosensor using indium-tin-oxide electrodes.

PubMed

Choi, Chang Kyoung; Kihm, Kenneth D; English, Anthony E

2007-06-01

The use of an optically thin indium-tin-oxide (ITO) electrode is presented for an optoelectric biosensor simultaneously recording optical images and microimpedance to examine time-dependent cellular growth. The transmittance of a 100 nm thick ITO electrode layer is approximately the same as the transmittance of a clean glass substrate, whereas the industry-standard Au(47.5 nm)/Ti(2.5 nm) electrode layer drops the transmittance to less than 10% of that of the glass substrate. The simultaneous optoelectric measurements permit determining the correlation of the cell-covered area increase with the microimpedance increase, and the example results obtained for live porcine pulmonary artery endothelial cells delineate the quantitative and comprehensive nature of cellular attachment and spreading to the substrate, which has not been clearly perceived before.

Determination of the solubility of tin indium oxide using in situ and ex x-ray diffraction

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

Gonzalez, G. B.; Mason, T. O.; Okasinski, J. S.

A novel approach to determine the thermodynamic solubility of tin in indium oxide via the exsolution from tin overdoped nano-ITO powders is presented. High-energy, in situ and ex situ synchrotron X-ray diffraction was utilized to study the solubility limit at temperatures ranging from 900 C to 1375 C. The tin exsolution from overdoped nanopowders and the formation of In{sub 4}Sn{sub 3}O{sub 12} were observed in situ during the first 4-48 h of high-temperature treatment. Samples annealed between 900 C and 1175 C were also studied ex situ with heat treatments for up to 2060 h. Structural results obtained from Rietveldmore » analysis include compositional phase analysis, atomic positions, and lattice parameters. The tin solubility in In{sub 2}O{sub 3} was determined using the phase analysis compositions from X-ray diffraction and the elemental compositions obtained from X-ray fluorescence. Experimental complications that can lead to incorrect tin solubility values in the literature are discussed.« less

Photocatalytic degradation of Orange G dye under solar light using nanocrystalline semiconductor metal oxide.

PubMed

Thennarasu, G; Kavithaa, S; Sivasamy, A

2011-08-01

The photocatalytic degradation of Orange G (OG) dye has been investigated using synthesised nanocrystalline ZnO as a photocatalyst and sunlight as the irradiation source. The formation of ZnO prepared from its precursor was confirmed through FT-IR and powder X-ray diffraction analyses. Surface morphology was characterised by scanning electron microscope and transmission electron microscope analysis. Band gap energy of synthesised nanocrystalline ZnO was calculated using diffuse reflectance spectroscopy (DRS). Different experimental parameters such as effects of pH, dye concentrations and mass of catalyst were standardised in order to achieve complete degradation of the dye molecules under solar light irradiation. The kinetics of oxidation of OG was also studied. The complete degradation of OG was evident after 90 min of irradiation at an initial pH of 6.86. The degradation of OG was confirmed by UV-Visible spectrophotometer, high-pressure liquid chromatography, ESI-Mass and chemical oxygen demand analyses. The adsorption of dye onto catalytic surface was analysed employing model equations such as Langmuir and Freundlich isotherms, and it was found that the Langmuir isotherm model best fitted the adsorption data. The solar photodegradation of OG followed pseudo-first-order kinetics. HPLC and ESI-Mass analyses of the degraded samples suggested that the dye molecules were readily degraded under solar irradiation with nanocrystalline ZnO.

Enhancement of the electrical characteristics of thin-film transistors with indium-zinc-tin oxide/Ag/indium-zinc-tin oxide multilayer electrodes

NASA Astrophysics Data System (ADS)

Oh, Dohyun; Yun, Dong Yeol; Cho, Woon-Jo; Kim, Tae Whan

2014-08-01

Transparent indium-zinc-tin oxide (IZTO)-based thin-film transistors (TFTs) with IZTO/Ag/IZTO multilayer electrodes were fabricated on glass substrates using a tilted dual-target radio-frequency magnetron sputtering system. The IZTO TFTs with IZTO/Ag/IZTO multilayer electrodes exhibited a high optical transmittance in a visible region. The threshold voltage, the mobility, and the on/off-current ratio of the TFTs with IZTO/Ag/IZTO multilayer electrodes were enhanced in comparison with those of the TFTs with ITO electrodes. The source/drain contact resistance of the IZTO TFTs with IZTO/Ag/IZTO multilayer electrodes was smaller than that of the IZTO TFTs with ITO electrodes, resulting in enhancement of their electrical characteristics.

Evidence of alloy formation during reduction of platinized tin oxide surfaces

NASA Technical Reports Server (NTRS)

Gardner, Steven D.; Hoflund, Gar B.; Davidson, Mark R.; Schryer, David R.

1989-01-01

Ion scattering spectroscopy, Auger electron spectroscopy, and electron spectroscopy for chemical analysis have been used to examine a platinized tin oxide catalyst surface before, during, and after reduction by annealing under vacuum at 250 to 450 C. These techniques were then used to examine the reduced surface after a room-temperature, low-pressure oxygen exposure. The spectral results and the behavior of the reduced surface toward oxygen exposure both indicate that a Pt/Sn alloy is produced during reduction.

Effect of fluorine doping on highly transparent conductive spray deposited nanocrystalline tin oxide thin films

NASA Astrophysics Data System (ADS)

Moholkar, A. V.; Pawar, S. M.; Rajpure, K. Y.; Bhosale, C. H.; Kim, J. H.

2009-09-01

The undoped and fluorine doped thin films are synthesized by using cost-effective spray pyrolysis technique. The dependence of optical, structural and electrical properties of SnO 2 films, on the concentration of fluorine is reported. Optical absorption, X-ray diffraction, scanning electron microscope (SEM) and Hall effect studies have been performed on SnO 2:F (FTO) films coated on glass substrates. The film thickness varies from 800 to 1572 nm. X-ray diffraction pattern reveals the presence of cassiterite structure with (2 0 0) preferential orientation for FTO films. The crystallite size varies from 35 to 66 nm. SEM and AFM study reveals the surface of FTO to be made of nanocrystalline particles. The electrical study reveals that the films are degenerate and exhibit n-type electrical conductivity. The 20 wt% F doped film has a minimum resistivity of 3.8 × 10 -4 Ω cm, carrier density of 24.9 × 10 20 cm -3 and mobility of 6.59 cm 2 V -1 s -1. The sprayed FTO film having minimum resistance of 3.42 Ω/cm 2, highest figure of merit of 6.18 × 10 -2 Ω -1 at 550 nm and 96% IR reflectivity suggest, these films are useful as conducting layers in electrochromic and photovoltaic devices and also as the passive counter electrode.

Solvent free tin oxide nanoparticle for gas sensing application

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

Ranjan, Pranay, E-mail: pranjan@iitp.ac.in; Thakur, Ajay D.; Centre for Energy and Environment, Indian Institute of Technology Patna, Patliputra, Patna 800013 India

2016-05-06

A new modified technique of synthesizing tin oxide nanoparticles with crystallite size of 2 nm to 6 nm has been developed. Surface area of the nanoparticle has been increased as we approached towards the Debye length. Such a techniques for approaching the Debye length is expected to bring remarkable changes in the properties of resistive based gas sensors. The technique used here is less toxic, economical and has high yield. Phase purity, size, shape and composition has been investigated using x-ray diffraction, micro Raman, scanning electron microscopy and energy dispersive x ray spectroscopy. While surface area has been calculated through Brunaur-Emmett-Teller (BET).

Bandgap engineering through nanocrystalline magnetic alloy grafting on reduced graphene oxide.

PubMed

De, D; Chakraborty, M; Majumdar, S; Giri, S

2014-09-28

High conductivity and the absence of ferromagnetism in pristine graphene fail to satisfy primary criteria for possible technological application in spintronics. Opening of the bandgap in graphene is primarily desirable for such applications. We report a simplified and novel approach of controlled grafting of a magnetic alloy on reduced graphene oxide. This eventually leads to ferromagnetism of the stable hybrid material at room temperature, with a large moment (∼1.2 μB) and a remarkable decrease in conductivity (∼10 times) compared to highly ordered pyrolytic graphite. Our model band-structure calculation indicates that the combined effect of controlled vacancies and impurities attributed to the nanocrystalline alloy grafting leads to a promising step toward band gap engineering.

Surface smoothing of indium tin oxide film by laser-induced photochemical etching

NASA Astrophysics Data System (ADS)

Kang, JoonHyun; Kim, Young-Hwan; Kwon, Seok Joon; Park, Joon-Suh; Park, Kyoung Wan; Park, Jae-Gwan; Han, Il Ki

2017-12-01

Surface smoothing of indium tin oxide (ITO) film by laser irradiation was demonstrated. The ITO surface was etched by choline radicals, which were activated by laser irradiation at a wavelength of 532 nm. The RMS surface roughness was improved from 5.6 to 4.6 nm after 10 min of laser irradiation. We also showed the changes in the surface morphology of the ITO film with various irradiation powers and times.

Combined flame and solution synthesis of nanoscale tungsten-oxide and zinc/tin-oxide heterostructures

NASA Astrophysics Data System (ADS)

Dong, Zhizhong; Huo, Di; Kear, Bernard H.; Tse, Stephen D.

2015-12-01

Heterostructures of tungsten-oxide nanowires decorated with zinc/tin-oxide nanostructures are synthesized via a combined flame and solution synthesis approach. Vertically well-aligned tungsten-oxide nanowires are grown on a tungsten substrate by a flame synthesis method. Here, tetragonal WO2.9 nanowires (diameters of 20-50 nm, lengths >10 μm, and coverage density of 109-1010 cm-2) are produced by the vapor-solid mechanism at 1720 K. Various kinds of Zn/Sn-oxide nanostructures are grown or deposited on the WO2.9 nanowires by adjusting the Sn2+ : Zn2+ molar ratio in an aqueous ethylenediamine solution at 65 °C. With WO2.9 nanowires serving as the base structures, sequential growth or deposition on them of hexagonal ZnO nanoplates, Zn2SnO4 nanocubes, and SnO2 nanoparticles are attained for Sn2+ : Zn2+ ratios of 0 : 1, 1 : 10, and 10 : 1, respectively, along with different saturation conditions. High-resolution transmission electron microscopy of the interfaces at the nanoheterojunctions shows abrupt interfaces for ZnO/WO2.9 and Zn2SnO4/WO2.9, despite lattice mismatches of >20%.

Properties of Resistive Hydrogen Sensors as a Function of Additives of 3 D-Metals Introduced in the Volume of Thin Nanocrystalline SnO2 Films

NASA Astrophysics Data System (ADS)

Sevast'yanov, E. Yu.; Maksimova, N. K.; Potekaev, A. I.; Sergeichenko, N. V.; Chernikov, E. V.; Almaev, A. V.; Kushnarev, B. O.

2017-11-01

Analysis of the results of studying electrical and gas sensitive characteristics of the molecular hydrogen sensors based on thin nanocrystalline SnO2 films coated with dispersed Au layers and containing Au+Ni and Au+Co impurities in the bulk showed that the characteristics of these sensors are more stable under the prolonged exposure to hydrogen in comparison with Au/SnO2:Sb, Au films modified only with gold. It has been found that introduction of the nickel and cobalt additives increases the band bending at the grain boundaries of tin dioxide already in freshly prepared samples, which indicates an increase in the density Ni of the chemisorbed oxygen. It is important that during testing, the band bending eφs at the grain boundaries of tin dioxide additionally slightly increases. It can be assumed that during crystallization of films under thermal annealing, the 3d-metal atoms in the SnO2 volume partially segregate on the surface of microcrystals and form bonds with lattice oxygen, the superstoichiometric tin atoms are formed, and the density Ni increases. If the bonds of oxygen with nickel and cobalt are stronger than those with tin, then, under the prolonged tests, atomic hydrogen will be oxidized not by lattice oxygen, but mainly by the chemisorbed one. In this case, stability of the sensors' characteristics increases.

Platinized tin oxide catalysts for CO2 lasers: Effects of pretreatment

NASA Technical Reports Server (NTRS)

Gardner, Steven D.; Hoflund, Gar B.; Schryer, David R.; Upchurch, Billy T.

1990-01-01

Platinized tin oxide surfaces used for low-temperature CO oxidation in CO2 lasers have been characterized before and after reduction in CO at 125 and 250 C using ion scattering spectroscopy (ISS) and X ray photoelectron spectroscopy (XPS). XPS indicates that the Pt is present initially as PtO2. Reduction at 125 C converts the PtO2 to Pt(OH)2 while reduction at 250 C converts the PtO2 to metallic Pt. ISS shows that the Pt in the outermost atomic layer of the catalyst is mostly covered by substrate species during the 250 C reduction. Both the ISS and XPS results are consistent with Pt/Sn alloy formation. The surface dehydration and migration of substrate species over surface Pt and Sn appear to explain why a CO pretreatment at 250 C produces inferior CO oxidation activities compared to a 125 C pretreatment.

Platinized tin oxide catalysts for CO2 lasers - Effects of pretreatment

NASA Technical Reports Server (NTRS)

Gardner, Steven D.; Hoflund, Gar B.; Schryer, David R.; Upchurch, Billy T.

1989-01-01

Platinized tin oxide surfaces used for low-temperature CO oxidation in CO2 lasers have been characterized before and after reduction in CO at 125 and 250 C using ion scattering spectroscopy (ISS) and X-ray photoelectron spectroscopy (XPS). XPS indicates that the Pt is present initially as Pto2. Reduction at 125 C converts the PtO2 to Pt(OH)2 while reduction at 250 C converts the PtO2 to metallic Pt. ISS shows that the Pt in the outermost atomic layer of the catalyst is mostly covered by substrate species during the 250 C reduction. Both the ISS and XPS results are consistent with Pt/Sn alloy formation. The surface dehydration and migration of substrate species over surface Pt and Sn appear to explain why a CO pretreatment at 250 C produces inferior CO oxidation activities compared to a 125 C pretreatment.

Highly conducting and crystalline doubly doped tin oxide films fabricated using a low-cost and simplified spray technique

NASA Astrophysics Data System (ADS)

Ravichandran, K.; Muruganantham, G.; Sakthivel, B.

2009-11-01

Doubly doped (simultaneous doping of antimony and fluorine) tin oxide films (SnO 2:Sb:F) have been fabricated by employing an inexpensive and simplified spray technique using perfume atomizer from aqueous solution of SnCl 2 precursor. The structural studies revealed that the films are highly crystalline in nature with preferential orientation along the (2 0 0) plane. It is found that the size of the crystallites of the doubly doped tin oxide films is larger (69 nm) than that (27 nm) of their undoped counterparts. The dislocation density of the doubly doped film is lesser (2.08×10 14 lines/m 2) when compared with that of the undoped film (13.2×10 14 lines/m 2), indicating the higher degree of crystallinity of the doubly doped films. The SEM images depict that the films are homogeneous and uniform. The optical transmittance in the visible range and the optical band gap of the doubly doped films are 71% and 3.56 eV respectively. The sheet resistance (4.13 Ω/□) attained for the doubly doped film in this study is lower than the values reported for spray deposited fluorine or antimony doped tin oxide films prepared from aqueous solution of SnCl 2 precursor (without using methanol or ethanol).

Reactive ion etching of indium-tin oxide films by CCl4-based Inductivity Coupled Plasma

NASA Astrophysics Data System (ADS)

Juneja, Sucheta; Poletayev, Sergey D.; Fomchenkov, Sergey; Khonina, Svetlana N.; Skidanov, Roman V.; Kazanskiy, Nikolay L.

2016-08-01

Indium tin oxide (ITO) films have been a subject of extensive studies in fabrication of micro-electronic devices for opto-electronic applications ranging from anti-reflection coatings to transparent contacts in photovoltaic devices. In this paper, a new and effective way of reactive ion etching of a conducting indium-tin oxide (ITO) film with Carbon tetrachloride (CCl4) has been investigated. CCl4 plasma containing an addition of gases mixture of dissociated argon and oxygen were used. Oxygen is added to increase the etchant percentage whereas argon was used for stabilization of plasma. The etching characteristics obtained with these gaseous mixtures were explained based on plasma etch chemistry and etching regime of ITO films. An etch rate as high as ∼20 nm/min can be achieved with a controlled process parameter such as power density, total flow rate, composition of reactive gases gas and pressure. Our Investigation represents some of the extensive work in this area.

Study of indium tin oxide films exposed to atomic axygen

NASA Technical Reports Server (NTRS)

Snyder, Paul G.; De, Bhola N.; Woollam, John A.; Coutts, T. J.; Li, X.

1989-01-01

A qualitative simulation of the effects of atomic oxygen has been conducted on indium tin oxide (ITO) films prepared by dc sputtering onto room-temperature substrates, by exposing them to an RF-excited oxygen plasma and characterizing the resulting changes in optical, electrical, and structural properties as functions of exposure time with ellipsometry, spectrophotometry, resistivity, and X-ray measurements. While the films thus exposed exhibit reduced resistivity and optical transmission; both of these effects, as well as partial crystallization of the films, may be due to sample heating by the plasma. Film resistivity is found to stabilize after a period of exposure.

Evidence of nanocrystalline semiconducting graphene monoxide during thermal reduction of graphene oxide in vacuum.

PubMed

Mattson, Eric C; Pu, Haihui; Cui, Shumao; Schofield, Marvin A; Rhim, Sonny; Lu, Ganhua; Nasse, Michael J; Ruoff, Rodney S; Weinert, Michael; Gajdardziska-Josifovska, Marija; Chen, Junhong; Hirschmugl, Carol J

2011-12-27

As silicon-based electronics are reaching the nanosize limits of the semiconductor roadmap, carbon-based nanoelectronics has become a rapidly growing field, with great interest in tuning the properties of carbon-based materials. Chemical functionalization is a proposed route, but syntheses of graphene oxide (G-O) produce disordered, nonstoichiometric materials with poor electronic properties. We report synthesis of an ordered, stoichiometric, solid-state carbon oxide that has never been observed in nature and coexists with graphene. Formation of this material, graphene monoxide (GMO), is achieved by annealing multilayered G-O. Our results indicate that the resulting thermally reduced G-O (TRG-O) consists of a two-dimensional nanocrystalline phase segregation: unoxidized graphitic regions are separated from highly oxidized regions of GMO. GMO has a quasi-hexagonal unit cell, an unusually high 1:1 O:C ratio, and a calculated direct band gap of ∼0.9 eV.

Nanocrystalline SnO2 formation using energetic ion beam.

PubMed

Mohanty, T; Batra, Y; Tripathi, A; Kanjilal, D

2007-06-01

Nanocrystalline tin oxide (SnO2) thin films grown by RF magnetron sputtering technique were characterized by UV-Visible absorption spectroscopy and Photoluminescence spectroscopy. From atomic force microscopic (AFM) and Glancing angle X-ray diffraction (GAXRD) measurements, the radius of grains was found to be approximately 6+/-2 nm. The thin films were bombarded with 250 keV Xe2+ ion beam to observe the stability of nanophases against radiation. For ion bombarded films, optical absorption band edge is shifted towards red region. Atomic force microscopy studies show that the radius of the grains was increased to approximately 8 +/- 1 nm and the grains were nearly uniform in size. The size of the grains has been reduced after ion bombardment in the case of films grown on Si. During this process, defects such as vacancies, voids were generated in the films as well as in the substrates. Ion bombardment induces local temperature increase of thin films causing melting of films. Ion beam induced defects enhances the diffusion of atoms leading to uniformity in size of grains. The role of matrix on ion beam induced grain growth is discussed.

Nonvolatile memory behavior of nanocrystalline cellulose/graphene oxide composite films

NASA Astrophysics Data System (ADS)

Valentini, L.; Cardinali, M.; Fortunati, E.; Kenny, J. M.

2014-10-01

With the continuous advance of modern electronics, the demand for nonvolatile memory cells rapidly grows. In order to develop post-silicon electronic devices, it is necessary to find innovative solutions to the eco-sustainability problem of materials for nonvolatile memory cells. In this work, we realized a resistive memory device based on graphene oxide (GO) and GO/cellulose nanocrystals (CNC) thin films. Aqueous solutions of GO and GO with CNC have been prepared and drop cast between two metal electrodes. Such thin-film based devices showed a transition between low and high conductivity states upon the forward and backward sweeping of an external electric field. This reversible current density transition behavior demonstrates a typical memory characteristic. The obtained results open an easy route for electronic information storage based on the integration of nanocrystalline cellulose onto graphene based devices.

Nonvolatile memory behavior of nanocrystalline cellulose/graphene oxide composite films

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

Valentini, L., E-mail: luca.valentini@unipg.it; Cardinali, M.; Fortunati, E.

2014-10-13

With the continuous advance of modern electronics, the demand for nonvolatile memory cells rapidly grows. In order to develop post-silicon electronic devices, it is necessary to find innovative solutions to the eco-sustainability problem of materials for nonvolatile memory cells. In this work, we realized a resistive memory device based on graphene oxide (GO) and GO/cellulose nanocrystals (CNC) thin films. Aqueous solutions of GO and GO with CNC have been prepared and drop cast between two metal electrodes. Such thin-film based devices showed a transition between low and high conductivity states upon the forward and backward sweeping of an external electricmore » field. This reversible current density transition behavior demonstrates a typical memory characteristic. The obtained results open an easy route for electronic information storage based on the integration of nanocrystalline cellulose onto graphene based devices.« less

Selective Oxidation of n-Hexane by Cu (II) Nanoclusters Supported on Nanocrystalline Zirconia Catalyst.

PubMed

Acharyya, Shankha Shubhra; Ghosh, Shilpi; Adak, Shubhadeep; Singh, Raghuvir; Saran, Sandeep; Bal, Rajaram

2015-08-01

Cu (II) nanoclusters supported on nanocrystalline zirconia catalyst (with size ~15 nm), was prepared by using cationic surfactant cetyltrimethylammonium in a hydrothermal synthesis method. The catalyst was characterized by XRD, XPS, TGA, SEM, TEM, FTIR and ICP-AES. The catalyst was found to be efficient in selective oxidation of n-hexane to 2-hexanol. An n-hexane conversion of 55%, with a 2-hexanol selectivity of 70% was achieved over this catalyst in liquid phase, without the use of any solvent. The catalyst can be reused several times without any significant activity loss.

A comparative study of TiN and TiC: Oxidation resistance and retention of xenon at high temperature and under degraded vacuum

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

Gavarini, S.; Bes, R.; Millard-Pinard, N.

2011-01-01

Dense TiN and TiC samples were prepared by hot pressing using micrometric powders. Xenon species (simulating rare gas fission products) were then implanted into the ceramics. The samples were annealed for 1 h at 1500 deg. C under several degraded vacuums with P{sub O{sub 2}} varying from 10{sup -6} to 2x10{sup -4} mbars. The oxidation resistance of the samples and their retention properties with respect to preimplanted xenon species were analyzed using scanning electron microscopy, grazing incidence x-ray diffraction, Rutherford backscattering spectrometry, and nuclear backscattering spectrometry. Results indicate that TiC is resistant to oxidation and does not release xenon formore » P{sub O{sub 2{<=}}}6x10{sup -6} mbars. When P{sub O{sub 2}} increases, geometric oxide crystallites appear at the surface depending on the orientation and size of TiC grains. These oxide phases are Ti{sub 2}O{sub 3}, Ti{sub 3}O{sub 5}, and TiO{sub 2}. Apparition of oxide crystallites is associated with the beginning of xenon release. TiC surface is completely covered by the oxide phases at P{sub O{sub 2}}=2x10{sup -4} mbars up to a depth of 3 {mu}m and the xenon is then completely released. For TiN samples, the results show a progressive apparition of oxide crystallites (Ti{sub 3}O{sub 5} mainly) at the surface when P{sub O{sub 2}} increases. The presence of the oxide crystallites is also directly correlated with xenon release, the more oxide crystallites are growing the more xenon is released. TiN surface is completely covered by an oxide layer at P{sub O{sub 2}}=2x10{sup -4} mbars up to 1 {mu}m. A correlation between the initial fine microstructure of TiN and the properties of the growing layer is suggested.« less

Improving the efficiency of cadmium sulfide-sensitized titanium dioxide/indium tin oxide glass photoelectrodes using silver sulfide as an energy barrier layer and a light absorber

PubMed Central

2014-01-01

Cadmium sulfide (CdS) and silver sulfide (Ag2S) nanocrystals are deposited on the titanium dioxide (TiO2) nanocrystalline film on indium tin oxide (ITO) substrate to prepare CdS/Ag2S/TiO2/ITO photoelectrodes through a new method known as the molecular precursor decomposition method. The Ag2S is interposed between the TiO2 nanocrystal film and CdS nanocrystals as an energy barrier layer and a light absorber. As a consequence, the energy conversion efficiency of the CdS/Ag2S/TiO2/ITO electrodes is significantly improved. Under AM 1.5 G sunlight irradiation, the maximum efficiency achieved for the CdS(4)/Ag2S/TiO2/ITO electrode is 3.46%, corresponding to an increase of about 150% as compared to the CdS(4)/TiO2/ITO electrode without the Ag2S layer. Our experimental results show that the improved efficiency is mainly due to the formation of Ag2S layer that may increase the light absorbance and reduce the recombination of photogenerated electrons with redox ions from the electrolyte. PMID:25411566

Transparent indium-tin oxide/indium-gallium-zinc oxide Schottky diodes formed by gradient oxygen doping

NASA Astrophysics Data System (ADS)

Ho, Szuheng; Yu, Hyeonggeun; So, Franky

2017-11-01

Amorphous InGaZnO (a-IGZO) is promising for transparent electronics due to its high carrier mobility and optical transparency. However, most metal/a-IGZO junctions are ohmic due to the Fermi-level pinning at the interface, restricting their device applications. Here, we report that indium-tin oxide/a-IGZO Schottky diodes can be formed by gradient oxygen doping in the a-IGZO layer that would otherwise form an ohmic contact. Making use of back-to-back a-IGZO Schottky junctions, a transparent IGZO permeable metal-base transistor is also demonstrated with a high common-base gain.

Indium Tin Oxide Resistor-Based Nitric Oxide Microsensors

NASA Technical Reports Server (NTRS)

Xu, Jennifer C.; Hunter, Gary W.; Gonzalez, Jose M., III; Liu, Chung-Chiun

2012-01-01

A sensitive resistor-based NO microsensor, with a wide detection range and a low detection limit, has been developed. Semiconductor microfabrication techniques were used to create a sensor that has a simple, robust structure with a sensing area of 1.10 0.99 mm. A Pt interdigitated structure was used for the electrodes to maximize the sensor signal output. N-type semiconductor indium tin oxide (ITO) thin film was sputter-deposited as a sensing material on the electrode surface, and between the electrode fingers. Alumina substrate (250 m in thickness) was sequentially used for sensor fabrication. The resulting sensor was tested by applying a voltage across the two electrodes and measuring the resulting current. The sensor was tested at different concentrations of NO-containing gas at a range of temperatures. Preliminary results showed that the sensor had a relatively high sensitivity to NO at 450 C and 1 V. NO concentrations from ppm to ppb ranges were detected with the low limit of near 159 ppb. Lower NO concentrations are being tested. Two sensing mechanisms were involved in the NO gas detection at ppm level: adsorption and oxidation reactions, whereas at ppb level of NO, only one sensing mechanism of adsorption was involved. The NO microsensor has the advantages of high sensitivity, small size, simple batch fabrication, high sensor yield, low cost, and low power consumption due to its microsize. The resistor-based thin-film sensor is meant for detection of low concentrations of NO gas, mainly in the ppb or lower range, and is being developed concurrently with other sensor technology for multispecies detection. This development demonstrates that ITO is a sensitive sensing material for NO detection. It also provides crucial information for future selection of nanostructured and nanosized NO sensing materials, which are expected to be more sensitive and to consume less power.

Thermoelectric Properties and Thermal Tolerance of Indium Tin Oxide Nanowires.

PubMed

Hernandez, Jose A; Carpena Nunez, Jennifer; Fonseca, Luis F; Pettes, Michael Thompson; Yacaman, Miguel Jose; Benitez, Alfredo

2018-06-14

Single-crystalline indium tin oxide (ITO) nanowires were grown via a vapor-liquid-solid (VLS) method, with thermal tolerance up to ~1300°C. We report the electric and thermoelectric properties of the ITO nanowires before and after heat treatments and draw conclusions about their applicability as thermoelectric building blocks in nanodevices that can operate in high temperature conditions. The Seebeck coefficient and the thermal and electrical conductivities were measured in each individual nanowire by means of specialized micro-bridge thermometry devices. Measured data was analyzed and explained in terms of changes in charge carrier density, impurities and vacancies due to the thermal treatments. © 2018 IOP Publishing Ltd.

High-efficiency indium tin oxide/indium phosphide solar cells

NASA Technical Reports Server (NTRS)

Li, X.; Wanlass, M. W.; Gessert, T. A.; Emery, K. A.; Coutts, T. J.

1989-01-01

Improvements in the performance of indium tin oxide (ITO)/indium phosphide solar cells have been realized by the dc magnetron sputter deposition of n-ITO onto an epitaxial p/p(+) structure grown on commercial p(+) bulk substrates. The highest efficiency cells were achieved when the surface of the epilayer was exposed to an Ar/H2 plasma before depositing the bulk of the ITO in a more typical Ar/O2 plasma. With H2 processing, global efficiencies of 18.9 percent were achieved. It is suggested that the excellent performance of these solar cells results from the optimization of the doping, thickness, transport, and surface properties of the p-type base, as well as from better control over the ITO deposition procedure.

Co-precipitation synthesis of nano-composites consists of zinc and tin oxides coatings on glass with enhanced photocatalytic activity on degradation of Reactive Blue 160 KE2B.

PubMed

Habibi, Mohammad Hossein; Mardani, Maryam

2015-02-25

Nano-composite containing zinc oxide-tin oxide was obtained by a facile co-precipitation route using tin chloride tetrahydrate and zinc chloride as precursors and coated on glass by Doctor Blade deposition. The crystalline structure and morphology of composites were evaluated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The XRD results showed peaks relative to zinc oxide with hexagonal wurtzite structure and tin oxide with tetragonal structure. FESEM observations showed that the nano-composite consisted of aggregates of particles with an average particle size of 18 nm. The photocatalytic activity of the pure SnO2, pure ZnO, ZnSnO3-Zn2SnO4 and ZnO-SnO2 nano-structure thin films was examined using the degradation of a textile dye Reactive Blue 160 (KE2B). ZnO-SnO2 nano-composite showed enhanced photo-catalytic activity than the pure zinc oxide and tin oxide. The enhanced photo-catalytic activity of the nano-composite was ascribed to an improved charge separation of the photo-generated electron-hole pairs. Copyright © 2014 Elsevier B.V. All rights reserved.

Secondary ion mass spectrometric investigation on ruthenium oxide systems: a comparison between poly- and nanocrystalline deposits

PubMed

Barison; Barreca; Daolio; Fabrizio; Piccirillo

2000-01-01

The influence of different RuO(2) crystallite sizes was investigated by secondary ion mass spectrometry (SIMS) on the oxide deposited on various support materials (Ni, Ti, Al(2)O(3), oxidized Si(100)). In order to examine the effect of an oxidic environment on the film structure, RuO(2) 20%-TiO(2) 80% at. mixed oxide was deposited on Ti. The polycrystalline coatings were prepared by heating the Ru (and Ti)-containing solution dropped on the supports.1 RuO(2) nanocrystalline coatings were grown by chemical vapor deposition (CVD) from Ru(COD)(eta(3)-allyl)(2).2 The identification of mixed oxide clusters showed the higher reactivity of Ni and Al(2)O(3) over the other substrates. Diffusion and migration characteristics were observed to be influenced by the nature of the support. The results are complementary to those of a previous SIMS investigation.3 Copyright 2000 John Wiley & Sons, Ltd.

Synthesis and characterization of mesoporous indium tin oxide possessing an electronically conductive framework.

PubMed

Emons, Theo T; Li, Jianquan; Nazar, Linda F

2002-07-24

The new mesoporous transparent conducting oxide based on indium-tin-oxide, meso-ITO, has been synthesized by a modified sol-gel method, using CTAB as the surfactant. Critical was the employment of triethanolamine to control the rate of hydrolysis and inhibit deposition of the bulk oxides. Removal of the surfactant by calcination yielded a relatively well-ordered worm-hole motif arrangement of pores visible in the TEM and stable to 400 degrees C. BET measurements revealed no hysteresis in the absorption-desorption isotherm, consistent with a narrow pore-size distribution (between 20 and 40 A depending on the In:Sn ratio); surface areas ranged between 270 and 310 m2/g. This colorless material is the first mesoporous oxide exhibiting substantial framework conductivity, with a conductivity at 25 degrees C of 1.2 x 10-3 S/cm. This distinguishes it from mesoporous mixed-valence transition-metal oxides that exhibit weak hopping semiconductor behavior and much lower conductivity.

Low Temperature Synthesis of Fluorine-Doped Tin Oxide Transparent Conducting Thin Film by Spray Pyrolysis Deposition.

PubMed

Ko, Eun-Byul; Choi, Jae-Seok; Jung, Hyunsung; Choi, Sung-Churl; Kim, Chang-Yeoul

2016-02-01

Transparent conducting oxide (TCO) is widely used for the application of flat panel display like liquid crystal displays and plasma display panel. It is also applied in the field of touch panel, solar cell electrode, low-emissivity glass, defrost window, and anti-static material. Fluorine-doped tin oxide (FTO) thin films were fabricated by spray pyrolysis of ethanol-added FTO precursor solutions. FTO thin film by spray pyrolysis is very much investigated and normally formed at high temperature, about 500 degrees C. However, these days, flexible electronics draw many attentions in the field of IT industry and the research for flexible transparent conducting thin film is also required. In the industrial field, indium-tin oxide (ITO) film on polymer substrate is widely used for touch panel and displays. In this study, we investigated the possibility of FTO thin film formation at relatively low temperature of 250 degrees C. We found out that the control of volume of input precursor and exhaust gases could make it possible to form FTO thin film with a relatively low electrical resistance, less than 100 Ohm/sq and high optical transmittance about 88%.

Recent developments in the formation and structure of tin-iron oxides by laser pyrolysis

NASA Astrophysics Data System (ADS)

Alexandrescu, R.; Morjan, I.; Dumitrache, F.; Birjega, R.; Fleaca, C.; Soare, I.; Gavrila, L.; Luculescu, C.; Prodan, G.; Kuncser, V.; Filoti, G.

2011-04-01

Complex oxides demonstrate specific electric and magnetic properties which make them suitable for a wide variety of applications, including dilute magnetic semiconductors for spin electronics. A tin-iron oxide Sn 1- xFe xO 2 nanoparticulate material has been successfully synthesized by using the laser pyrolysis of tetramethyl tin-iron pentacarbonyl-air mixtures. Fe doping of SnO 2 nanoparticles has been varied systematically in the 3-10 at% range. As determined by EDAX, the Fe/Sn ratio (in at%) in powders varied between 0.14 and 0.64. XRD studies of Sn 1- xFe xO 2 nanoscale powders, revealed only structurally modified SnO 2 due to the incorporation of Fe into the lattice mainly by substitutional changes. The substitution of Fe 3+ in the Sn 4+ positions (Fe 3+ has smaller ionic radius as compared to the ionic radius of 0.69 Å for Sn 4+) with the formation of a mixed oxide Sn 1- xFe xO 2 is suggested. A lattice contraction consistent with the determined Fe/Sn atomic ratios was observed. The nanoparticle size decreases with the Fe doping (about 7 nm for the highest Fe content). Temperature dependent 57Fe Mössbauer spectroscopy data point to the additional presence of defected Fe 3+-based oxide nanoclusters with blocking temperatures below 60 K. A new Fe phase presenting magnetic order at substantially higher temperatures was evidenced and assigned to a new type of magnetism relating to the dispersed Fe ions into the SnO 2 matrix.

Nanocrystalline SnO2:F thin films for liquid petroleum gas sensors.

PubMed

Chaisitsak, Sutichai

2011-01-01

This paper reports the improvement in the sensing performance of nanocrystalline SnO(2)-based liquid petroleum gas (LPG) sensors by doping with fluorine (F). Un-doped and F-doped tin oxide films were prepared on glass substrates by the dip-coating technique using a layer-by-layer deposition cycle (alternating between dip-coating a thin layer followed by a drying in air after each new layer). The results showed that this technique is superior to the conventional technique for both improving the film thickness uniformity and film transparency. The effect of F concentration on the structural, surface morphological and LPG sensing properties of the SnO(2) films was investigated. Atomic Force Microscopy (AFM) and X-ray diffraction pattern measurements showed that the obtained thin films are nanocrystalline SnO(2) with nanoscale-textured surfaces. Gas sensing characteristics (sensor response and response/recovery time) of the SnO(2):F sensors based on a planar interdigital structure were investigated at different operating temperatures and at different LPG concentrations. The addition of fluorine to SnO(2) was found to be advantageous for efficient detection of LPG gases, e.g., F-doped sensors are more stable at a low operating temperature (300 °C) with higher sensor response and faster response/recovery time, compared to un-doped sensor materials. The sensors based on SnO(2):F films could detect LPG even at a low level of 25% LEL, showing the possibility of using this transparent material for LPG leak detection.

Nanocrystalline SnO2:F Thin Films for Liquid Petroleum Gas Sensors

PubMed Central

Chaisitsak, Sutichai

2011-01-01

This paper reports the improvement in the sensing performance of nanocrystalline SnO2-based liquid petroleum gas (LPG) sensors by doping with fluorine (F). Un-doped and F-doped tin oxide films were prepared on glass substrates by the dip-coating technique using a layer-by-layer deposition cycle (alternating between dip-coating a thin layer followed by a drying in air after each new layer). The results showed that this technique is superior to the conventional technique for both improving the film thickness uniformity and film transparency. The effect of F concentration on the structural, surface morphological and LPG sensing properties of the SnO2 films was investigated. Atomic Force Microscopy (AFM) and X-ray diffraction pattern measurements showed that the obtained thin films are nanocrystalline SnO2 with nanoscale-textured surfaces. Gas sensing characteristics (sensor response and response/recovery time) of the SnO2:F sensors based on a planar interdigital structure were investigated at different operating temperatures and at different LPG concentrations. The addition of fluorine to SnO2 was found to be advantageous for efficient detection of LPG gases, e.g., F-doped sensors are more stable at a low operating temperature (300 °C) with higher sensor response and faster response/recovery time, compared to un-doped sensor materials. The sensors based on SnO2:F films could detect LPG even at a low level of 25% LEL, showing the possibility of using this transparent material for LPG leak detection. PMID:22164007

Effects on Organic Photovoltaics Using Femtosecond-Laser-Treated Indium Tin Oxides.

PubMed

Chen, Mei-Hsin; Tseng, Ya-Hsin; Chao, Yi-Ping; Tseng, Sheng-Yang; Lin, Zong-Rong; Chu, Hui-Hsin; Chang, Jan-Kai; Luo, Chih-Wei

2016-09-28

The effects of femtosecond-laser-induced periodic surface structures (LIPSS) on an indium tin oxide (ITO) surface applied to an organic photovoltaic (OPV) system were investigated. The modifications of ITO induced by LIPPS in OPV devices result in more than 14% increase in power conversion efficiency (PCE) and short-circuit current density relative to those of the standard device. The basic mechanisms for the enhanced short-circuit current density are attributed to better light harvesting, increased scattering effects, and more efficient charge collection between the ITO and photoactive layers. Results show that higher PCEs would be achieved by laser-pulse-treated electrodes.

Tin in a chondritic interplanetary dust particle

NASA Technical Reports Server (NTRS)

Rietmeijer, Frans J. M.

1989-01-01

Submicron platey Sn-rich grains are present in chondritic porous interplanetary dust particle (IDP) W7029 A and it is the second occurrence of a tin mineral in a stratospheric micrometeorite. Selected Area Electron Diffraction data for the Sn-rich grains match with Sn2O3 and Sn3O4. The oxide(s) may have formed in the solar nebula when tin metal catalytically supported reduction of CO or during flash heating on atmospheric entry of the IDP. The presence of tin is consistent with enrichments for other volatile trace elements in chondritic IDPs and may signal an emerging trend toward nonchondritic volatile element abundances in chondritic IDPs. The observation confirms small-scale mineralogical heterogeneity in fine-grained chondritic porous interplanetary dust.

Investigation of the properties of Sb doping on tin oxide SNO2 materials for technological applications

NASA Astrophysics Data System (ADS)

Hachoun, Z.; Ouerdane, A.; Bouslama, M.; Ghaffour, M.; Abdellaoui, A.; Caudano, Y.; benamara, A. Ali

2016-04-01

The conductivities of the oxide SnO2 is dependent on the nature of the surrounding gas. This property stems from the adsorption or desorption on the surface of oxide grains. These phenomena are usually accompanied by electronic transfer between the adsorbed molecule and the semiconductor material, changing its conductivity. Tin oxidation and Sb doping were realized without and with heating process. The XPS technique and the TEM microscopy showed the synthesized nanocrystals. Simulated Monte Carlo program Casino is used for a scanning its profile. The surface characteristics are highlighted in the aim to be used as spatial gas sensors.

Low temperature processed complementary metal oxide semiconductor (CMOS) device by oxidation effect from capping layer.

PubMed

Wang, Zhenwei; Al-Jawhari, Hala A; Nayak, Pradipta K; Caraveo-Frescas, J A; Wei, Nini; Hedhili, M N; Alshareef, H N

2015-04-20

In this report, both p- and n-type tin oxide thin-film transistors (TFTs) were simultaneously achieved using single-step deposition of the tin oxide channel layer. The tuning of charge carrier polarity in the tin oxide channel is achieved by selectively depositing a copper oxide capping layer on top of tin oxide, which serves as an oxygen source, providing additional oxygen to form an n-type tin dioxide phase. The oxidation process can be realized by annealing at temperature as low as 190 °C in air, which is significantly lower than the temperature generally required to form tin dioxide. Based on this approach, CMOS inverters based entirely on tin oxide TFTs were fabricated. Our method provides a solution to lower the process temperature for tin dioxide phase, which facilitates the application of this transparent oxide semiconductor in emerging electronic devices field.

Low-temperature growth and electronic structures of ambipolar Yb-doped zinc tin oxide transparent thin films

NASA Astrophysics Data System (ADS)

Oh, Seol Hee; Ferblantier, Gerald; Park, Young Sang; Schmerber, Guy; Dinia, Aziz; Slaoui, Abdelilah; Jo, William

2018-05-01

The compositional dependence of the crystal structure, optical transmittance, and surface electric properties of the zinc tin oxide (Zn-Sn-O, shortened ZTO) thin films were investigated. ZTO thin films with different compositional ratios were fabricated on glass and p-silicon wafers using radio frequency magnetron sputtering. The binding energy of amorphous ZTO thin films was examined by a X-ray photoelectron spectroscopy. The optical transmittance over 70% in the visible region for all the ZTO films was observed. The optical band gap of the ZTO films was changed as a result of the competition between the Burstein-Moss effect and renormalization. An electron concentration in the films and surface work function distribution were measured by a Hall measurement and Kelvin probe force microscopy, respectively. The mobility of the n- and p-type ZTO thin films have more than 130 cm2/V s and 15 cm2/V s, respectively. We finally constructed the band structure which contains band gap, work function, and band edges such as valence band maximum and conduction band minimum of ZTO thin films. The present study results suggest that the ZTO thin film is competitive compared with the indium tin oxide, which is a representative material of the transparent conducting oxides, regarding optoelectronic devices applications.

Development of p-type oxide semiconductors based on tin oxide and its alloys: application to thin film transistors

NASA Astrophysics Data System (ADS)

Barros, Ana Raquel Xarouco de

In spite of the recent p-type oxide TFTs developments based on SnOx and CuxO, the results achieved so far refer to devices processed at high temperatures and are limited by a low hole mobility and a low On-Off ratio and still there is no report on p-type oxide TFTs with performance similar to n-type, especially when comparing their field-effect mobility values, which are at least one order of magnitude higher on n-type oxide TFTs. Achieving high performance p-type oxide TFTs will definitely promote a new era for electronics in rigid and flexible substrates, away from silicon. None of the few reported p-channel oxide TFTs is suitable for practical applications, which demand significant improvements in the device engineering to meet the real-world electronic requirements, where low processing temperatures together with high mobility and high On-Off ratio are required for TFT and CMOS applications. The present thesis focuses on the study and optimization of p-type thin film transistors based on oxide semiconductors deposited by r.f. magnetron sputtering without intentional substrate heating. In this work several p-type oxide semiconductors were studied and optimized based on undoped tin oxide, Cu-doped SnOx and In-doped SnO2.

Optically active polyurethane@indium tin oxide nanocomposite: Preparation, characterization and study of infrared emissivity

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

Yang, Yong; Zhou, Yuming, E-mail: ymzhou@seu.edu.cn; Ge, Jianhua

Highlights: ► Silane coupling agent of KH550 was used to connect the ITO and polyurethanes. ► Infrared emissivity values of the hybrids were compared and analyzed. ► Interfacial synergistic action and orderly secondary structure were the key factors. -- Abstract: Optically active polyurethane@indium tin oxide and racemic polyurethane@indium tin oxide nanocomposites (LPU@ITO and RPU@ITO) were prepared by grafting the organics onto the surfaces of modified ITO nanoparticles. LPU@ITO and RPU@ITO composites based on the chiral and racemic tyrosine were characterized by FT-IR, UV–vis spectroscopy, X-ray diffraction (XRD), SEM, TEM, and thermogravimetric analysis (TGA), and the infrared emissivity values (8–14 μm)more » were investigated in addition. The results indicated that the polyurethanes had been successfully grafted onto the surfaces of ITO without destroying the crystalline structure. Both composites possessed the lower infrared emissivity values than the bare ITO nanoparticles, which indicated that the interfacial interaction had great effect on the infrared emissivity. Furthermore, LPU@ITO based on the optically active polyurethane had the virtue of regular secondary structure and more interfacial synergistic actions between organics and inorganics, thus it exhibited lower infrared emissivity value than RPU@ITO based on the racemic polyurethane.« less

The influence of interfacial defects on fast charge trapping in nanocrystalline oxide-semiconductor thin film transistors

NASA Astrophysics Data System (ADS)

Kim, Taeho; Hur, Jihyun; Jeon, Sanghun

2016-05-01

Defects in oxide semiconductors not only influence the initial device performance but also affect device reliability. The front channel is the major carrier transport region during the transistor turn-on stage, therefore an understanding of defects located in the vicinity of the interface is very important. In this study, we investigated the dynamics of charge transport in a nanocrystalline hafnium-indium-zinc-oxide thin-film transistor (TFT) by short pulse I-V, transient current and 1/f noise measurement methods. We found that the fast charging behavior of the tested device stems from defects located in both the front channel and the interface, following a multi-trapping mechanism. We found that a silicon-nitride stacked hafnium-indium-zinc-oxide TFT is vulnerable to interfacial charge trapping compared with silicon-oxide counterpart, causing significant mobility degradation and threshold voltage instability. The 1/f noise measurement data indicate that the carrier transport in a silicon-nitride stacked TFT device is governed by trapping/de-trapping processes via defects in the interface, while the silicon-oxide device follows the mobility fluctuation model.

Nanocrystalline tin oxide nanofibers deposited by a novel focused electrospinning method. Application to the detection of TATP precursors.

PubMed

Santos, José Pedro; Fernández, Maria Jesús; Fontecha, José Luis; Matatagui, Daniel; Sayago, Isabel; Horrillo, Maria Carmen; Gracia, Isabel

2014-12-16

A new method of depositing tin dioxide nanofibers in order to develop chemical sensors is presented. It involves an electrospinning process with in-plane electrostatic focusing over micromechanized substrates. It is a fast and reproducible method. After an annealing process, which can be performed by the substrate heaters, it is observed that the fibers are intertwined forming porous networks that are randomly distributed on the substrate. The fiber diameters oscillate from 100 nm to 200 nm and fiber lengths reach several tens of microns. Each fiber has a polycrystalline structure with multiple nano-grains. The sensors have been tested for the detection of acetone and hydrogen peroxide (precursors of the explosive triacetone triperoxide, TATP) in air in the ppm range. High and fast responses to these gases have been obtained.

Synthesis of tin-containing polyimide films

NASA Technical Reports Server (NTRS)

Ezzell, S. A.; Taylor, L. T.

1984-01-01

A series of tin-containing polyimide films derived from either 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride or pyromellitic dianhydride and 4,4'-oxydianiline have been synthesized and their electrical properties examined. Highest quality materials (i.e., homogeneous, smooth surface, flexible) with the best electrical properties were doped with either SnCl2.2H2O or (n-Bu)2SnCl2. In all cases, extensive reactivity of the tin dopant with water, air or polyamic acid during imidization is observed. Lowered electrical surface resistivities appear to be correlatable with the presence of surface tin oxide on the film surface.

Low Temperature Processed Complementary Metal Oxide Semiconductor (CMOS) Device by Oxidation Effect from Capping Layer

PubMed Central

Wang, Zhenwei; Al-Jawhari, Hala A.; Nayak, Pradipta K.; Caraveo-Frescas, J. A.; Wei, Nini; Hedhili, M. N.; Alshareef, H. N.

2015-01-01

In this report, both p- and n-type tin oxide thin-film transistors (TFTs) were simultaneously achieved using single-step deposition of the tin oxide channel layer. The tuning of charge carrier polarity in the tin oxide channel is achieved by selectively depositing a copper oxide capping layer on top of tin oxide, which serves as an oxygen source, providing additional oxygen to form an n-type tin dioxide phase. The oxidation process can be realized by annealing at temperature as low as 190°C in air, which is significantly lower than the temperature generally required to form tin dioxide. Based on this approach, CMOS inverters based entirely on tin oxide TFTs were fabricated. Our method provides a solution to lower the process temperature for tin dioxide phase, which facilitates the application of this transparent oxide semiconductor in emerging electronic devices field. PMID:25892711

Plasma vapor deposited n-indium tin oxide/p-copper indium oxide heterojunctions for optoelectronic device applications

NASA Astrophysics Data System (ADS)

Jaya, T. P.; Pradyumnan, P. P.

2017-12-01

Transparent crystalline n-indium tin oxide/p-copper indium oxide diode structures were fabricated on quartz substrates by plasma vapor deposition using radio frequency (RF) magnetron sputtering. The p-n heterojunction diodes were highly transparent in the visible region and exhibited rectifying current-voltage (I-V) characteristics with a good ideality factor. The sputter power during fabrication of the p-layer was found to have a profound effect on I-V characteristics, and the diode with the p-type layer deposited at a maximum power of 200 W exhibited the highest value of the diode ideality factor (η value) of 2.162, which suggests its potential use in optoelectronic applications. The ratio of forward current to reverse current exceeded 80 within the range of applied voltages of -1.5 to +1.5 V in all cases. The diode structure possessed an optical transmission of 60-70% in the visible region.

Structural, photoconductivity, and dielectric studies of polythiophene-tin oxide nanocomposites

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

Murugavel, S., E-mail: starin85@gmail.com; Malathi, M., E-mail: mmalathi@vit.ac.in

2016-09-15

Highlights: • Synthesis of polythiophene-tin oxide nanocomposites confirmed by FTIR and EDAX. • SEM shows SnO{sub 2} nanoparticles embedded within polythiophene matrix. • Stability and isoelectric point suggest nanoparticle–matrix interaction. • High dielectric constant due to high Maxwell–Wagner interfacial polarization. - Abstract: Polythiophene-tinoxide (PT-SnO{sub 2}) nanocomposites were prepared by in situ chemical oxidative polymerization, in the presence of various concentrations of SnO{sub 2} nanoparticles. Samples were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy and Zeta potential measurements. Morphologies and elemental compositions were investigated by transmission electron microscopy, field-emission scanning electron microscopy and energy-dispersive X-ray spectroscopy.more » The photoconductivity of the nanocomposites was studied by field-dependent dark and photo conductivity measurements. Their dielectric properties were investigated using dielectric spectroscopy, in the frequency range of 1kHz–1 MHz. The results indicated that the SnO{sub 2} nanoparticles in the PT-SnO{sub 2} nanocomposite were responsible for its enhanced dielectric performance.« less

Nanocrystalline semiconductor doped rare earth oxide for the photocatalytic degradation studies on Acid Blue 113: A di-azo compound under UV slurry photoreactor.

PubMed

Suganya Josephine, G A; Mary Nisha, U; Meenakshi, G; Sivasamy, A

2015-11-01

Preventive measures for the control of environmental pollution and its remediation has received much interest in recent years due to the world-wide increase in the contamination of water bodies. Contributions of these harmful effluents are caused by the leather processing, pharmaceutical, cosmetic, textile, agricultural and other chemical industries. Nowadays, advanced oxidation processes considered to be better option for the complete destruction of organic contaminants in water and wastewater. Acid Blue 113 is a most widely used di-azo compound in leather, textile, dying and food industry as a color rending compound. In the present study, we have reported the photo catalytic degradation of Acid Blue 113 using a nanocrystalline semiconductor doped rare earth oxide as a photo catalyst under UV light irradiation. The photocatalyst was prepared by a simple precipitation technique and were characterized by XRD, FT-IR, UV-DRS and FE-SEM analysis. The experimental results proved that the prepared photo catalyst was nanocrystalline and highly active in the UV region. The UV-DRS results showed the band gap energy was 3.15eV for the prepared photo catalyst. The photodegradation efficiency was analyzed by various experimental parameters such as pH, catalyst dosage, variation of substrate concentration and effect of electrolyte addition. The photo degradation process followed a pseudo first order kinetics and was continuously monitored by UV-visible spectrophotometer. The experimental results proved the efficacy of the nanocrystalline zinc oxide doped dysprosium oxide which are highly active under UV light irradiations. It is also suggested that the prepared material would find wider applications in environmental remediation technologies to remove the carcinogenic and toxic moieties present in the industrial effluents. Copyright © 2015 Elsevier Inc. All rights reserved.

Synthesis and properties of nanocrystalline copper indium oxide thin films deposited by Rf magnetron sputtering.

PubMed

Singh, Mandeep; Singh, V N; Mehta, B R

2008-08-01

Nanocrystalline copper indium oxide (CuInO2) thin films with particle size ranging from 25 nm to 71 nm have been synthesized from a composite target using reactive Rf magnetron sputtering technique. X-ray photoelectron spectroscopy (XPS) combined with glancing angle X-ray diffraction (GAXRD) analysis confirmed the presence of delafossite CuInO2 phase in these films. The optical absorption studies show the presence of two direct band gaps at 3.3 and 4.3 eV, respectively. The resistance versus temperature measurements show thermally activated hopping with activation energy of 0.84 eV to be the conduction mechanism.

Effect of annealing temperature on optical properties of binary zinc tin oxide nano-composite prepared by sol-gel route using simple precursors: structural and optical studies by DRS, FT-IR, XRD, FESEM investigations.

PubMed

Habibi, Mohammad Hossein; Mardani, Maryam

2015-02-25

Binary zinc tin oxide nano-composite was synthesized by a facile sol-gel method using simple precursors from the solutions consisting of zinc acetate, tin(IV) chloride and ethanol. Effect of annealing temperature on optical and structural properties was investigated using X-ray diffraction (XRD), diffuse reflectance spectra (DRS), field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). XRD results revealed the existence of the ZnO and SnO2 phases. FESEM results showed that binary zinc tin oxide nano-composites ranges from 56 to 60 nm in diameter at 400°C and 500°C annealing temperatures respectively. The optical band gap was increased from 2.72 eV to 3.11 eV with the increasing of the annealing temperature. FTIR results confirmed the presence of zinc oxide and tin oxide and the broad absorption peaks at 3426 and 1602 cm(-1) can be ascribed to the vibration of absorptive water, and the absorption peaks at 546, 1038 and 1410 cm(-1) are due to the vibration of Zn-O or Sn-O groups in binary zinc tin oxide. Copyright © 2014 Elsevier B.V. All rights reserved.

High Mobility Thin Film Transistors Based on Amorphous Indium Zinc Tin Oxide

PubMed Central

Noviyana, Imas; Lestari, Annisa Dwi; Putri, Maryane; Won, Mi-Sook; Bae, Jong-Seong; Heo, Young-Woo; Lee, Hee Young

2017-01-01

Top-contact bottom-gate thin film transistors (TFTs) with zinc-rich indium zinc tin oxide (IZTO) active layer were prepared at room temperature by radio frequency magnetron sputtering. Sintered ceramic target was prepared and used for deposition from oxide powder mixture having the molar ratio of In2O3:ZnO:SnO2 = 2:5:1. Annealing treatment was carried out for as-deposited films at various temperatures to investigate its effect on TFT performances. It was found that annealing treatment at 350 °C for 30 min in air atmosphere yielded the best result, with the high field effect mobility value of 34 cm2/Vs and the minimum subthreshold swing value of 0.12 V/dec. All IZTO thin films were amorphous, even after annealing treatment of up to 350 °C. PMID:28773058

Cyclic etching of tin-doped indium oxide using hydrogen-induced modified layer

NASA Astrophysics Data System (ADS)

Hirata, Akiko; Fukasawa, Masanaga; Nagahata, Kazunori; Li, Hu; Karahashi, Kazuhiro; Hamaguchi, Satoshi; Tatsumi, Tetsuya

2018-06-01

The rate of etching of tin-doped indium oxide (ITO) and the effects of a hydrogen-induced modified layer on cyclic, multistep thin-layer etching were investigated. It was found that ITO cyclic etching is possible by precisely controlling the hydrogen-induced modified layer. Highly selective etching of ITO/SiO2 was also investigated, and it was suggested that cyclic etching by selective surface adsorption of Si can precisely control the etch rates of ITO and SiO2, resulting in an almost infinite selectivity for ITO over SiO2 and in improved profile controllability.

Nanostructured tin oxide films: Physical synthesis, characterization, and gas sensing properties.

PubMed

Ingole, S M; Navale, S T; Navale, Y H; Bandgar, D K; Stadler, F J; Mane, R S; Ramgir, N S; Gupta, S K; Aswal, D K; Patil, V B

2017-05-01

Nanostructured tin oxide (SnO 2 ) films are synthesized using physical method i.e. thermal evaporation and are further characterized with X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy measurement techniques for confirming its structure and morphology. The chemiresistive properties of SnO 2 films are studied towards different oxidizing and reducing gases where these films have demonstrated considerable selectivity towards oxidizing nitrogen dioxide (NO 2 ) gas with a maximum response of 403% to 100ppm @200°C, and fast response and recovery times of 4s and 210s, respectively, than other test gases. In addition, SnO 2 films are enabling to detect as low as 1ppm NO 2 gas concentration @200°C with 23% response enhancement. Chemiresistive performances of SnO 2 films are carried out in the range of 1-100ppm and reported. Finally, plausible adsorption and desorption reaction mechanism of NO 2 gas molecules with SnO 2 film surface has been thoroughly discussed by means of an impedance spectroscopy analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

Dependence of the optical constants and the performance in the SPREE gas measurement on the thickness of doped tin oxide over coatings

NASA Astrophysics Data System (ADS)

Fischer, D.; Hertwig, A.; Beck, U.; Negendank, D.; Lohse, V.; Kormunda, M.; Esser, N.

2017-11-01

In this study, thickness related changes of the optical properties of doped tin oxide were studied. Two different sets of samples were prepared. The first set was doped with iron or nickel on silicon substrate with thicknesses of 29-56 nm, the second was iron doped on gold/glass substrate with 1.6-6.3 nm. The optical constants were determined by using spectral ellipsometry (SE) followed by modelling of the dielectric function with an oscillator model using Gaussian peaks. The analysis of the optical constants shows a dependence of the refraction and the absorption on the thickness of the doped tin oxide coating. In addition to the tin oxide absorption in the UV, one additional absorption peak was found in the near-IR/red which is related to plasmonic effects due to the doping. This peak shifts from the near-IR to the red part of the visible spectrum and becomes stronger by reducing the thickness, probably due to the formation of metal nanoparticles in this layer. These results were found for two different sets of samples by using the same optical model. Afterwards the second sample set was tested in the Surface Plasmon Resonance Enhanced Ellipsometric (SPREE) gas measurement with CO gas. It was found that the thickness has significant influence on the sensitivity and thus the adsorption of the CO gas. By increasing the thickness from 1.6 nm to 5.1 nm, the sensing ability is enhanced due to a higher coverage of the surface with the over coating. This is explained by the high affinity of CO molecules to the incorporated Fe-nanoparticles in the tin oxide coating. By increasing the thickness further to 6.3 nm, the sensing ability drops because the layer disturbs the SPR sensing effect too much.

Oxidation-Based Continuous Laser Writing in Vertical Nano-Crystalline Graphite Thin Films

PubMed Central

Loisel, Loïc; Florea, Ileana; Cojocaru, Costel-Sorin; Tay, Beng Kang; Lebental, Bérengère

2016-01-01

Nano and femtosecond laser writing are becoming very popular techniques for patterning carbon-based materials, as they are single-step processes enabling the drawing of complex shapes without photoresist. However, pulsed laser writing requires costly laser sources and is known to cause damages to the surrounding material. By comparison, continuous-wave lasers are cheap, stable and provide energy at a more moderate rate. Here, we show that a continuous-wave laser may be used to pattern vertical nano-crystalline graphite thin films with very few macroscale defects. Moreover, a spatially resolved study of the impact of the annealing to the crystalline structure and to the oxygen ingress in the film is provided: amorphization, matter removal and high oxygen content at the center of the beam; sp2 clustering and low oxygen content at its periphery. These data strongly suggest that amorphization and matter removal are controlled by carbon oxidation. The simultaneous occurrence of oxidation and amorphization results in a unique evolution of the Raman spectra as a function of annealing time, with a decrease of the I(D)/I(G) values but an upshift of the G peak frequency. PMID:27194181

Oxidation-Based Continuous Laser Writing in Vertical Nano-Crystalline Graphite Thin Films

NASA Astrophysics Data System (ADS)

Loisel, Loïc; Florea, Ileana; Cojocaru, Costel-Sorin; Tay, Beng Kang; Lebental, Bérengère

2016-05-01

Nano and femtosecond laser writing are becoming very popular techniques for patterning carbon-based materials, as they are single-step processes enabling the drawing of complex shapes without photoresist. However, pulsed laser writing requires costly laser sources and is known to cause damages to the surrounding material. By comparison, continuous-wave lasers are cheap, stable and provide energy at a more moderate rate. Here, we show that a continuous-wave laser may be used to pattern vertical nano-crystalline graphite thin films with very few macroscale defects. Moreover, a spatially resolved study of the impact of the annealing to the crystalline structure and to the oxygen ingress in the film is provided: amorphization, matter removal and high oxygen content at the center of the beam; sp2 clustering and low oxygen content at its periphery. These data strongly suggest that amorphization and matter removal are controlled by carbon oxidation. The simultaneous occurrence of oxidation and amorphization results in a unique evolution of the Raman spectra as a function of annealing time, with a decrease of the I(D)/I(G) values but an upshift of the G peak frequency.

Characterization study of polycrystalline tin oxide surfaces before and after reduction in CO

NASA Technical Reports Server (NTRS)

Drawdy, Jean E.; Hoflund, Gar B.; Davidson, Mark R.; Schryer, David R.

1990-01-01

Polycrystalline tin oxide surfaces have been examined before and after reduction in 40 Torr of CO at 100 and 175 C using Auger electron spectroscopy (AES), electron spectroscopy for chemical analysis (ESCA), ion scattering spectroscopy (ISS) and electron stimulated desorption (ESD). The changes in the surface composition and chemical states of the surface species generally are subtle for the reductive conditions used. However, significant changes do occur with regard to the amounts and the chemical forms of the hydrogen-containing species remaining after both the 100 and 175 C reductions.

Large-Scale Synthesis of Tin-Doped Indium Oxide Nanofibers Using Water as Solvent

NASA Astrophysics Data System (ADS)

Altecor, Aleksey; Mao, Yuanbing; Lozano, Karen

2012-09-01

Here we report the successful fabrication of tin-doped indium oxide (ITO) nanofibers using a scalable Forcespinning™ method. In this environmentally-friendly process, water was used as the only solvent for both Polyvinylpyrrolidone (PVP, the sacrificial polymer) and the metal chloride precursor salts. The obtained precursor nanofiber mats were calcinated at temperatures ranging from 500-800°C to produce ITO nanofibers with diameters as small as 400 nm. The developed ITO nanofibers were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction analysis.

The optical and structural properties of graphene nanosheets and tin oxide nanocrystals composite

NASA Astrophysics Data System (ADS)

Farheen, Parveen, Azra; Azam, Ameer

2018-05-01

A nanocomposite material consisting of metal oxide and reduced graphene oxide was prepared via simple, economic, and effective chemical reduction method. The synthesis strategy was based on the reduction of GO with Sn2+ ion that combines tin oxidation and GO reduction in one step, which provides a simple, low-cost and effective way to prepare graphene nanosheets/SnO2 nanocrystals composites because no additional chemicals were needed. SEM and TEM images shows the uniform distribution of the SnO2 nanocrystals on the Graphene nanosheets (GNs) surface and transmission electron microscope shows an average particle size of 2-4 nm. The mean crystallite size was calculated by Debye Scherrer formula and was found to be about 4.0 nm. Optical analysis was done by using UV-Visible spectroscopy technique and the band gap energy of the GNs/SnO2 nanocomposite was calculated by Tauc relation and came out to be 3.43eV.

Synthesis and properties of ternary mixture of nickel/cobalt/tin oxides for supercapacitors

NASA Astrophysics Data System (ADS)

Ferreira, C. S.; Passos, R. R.; Pocrifka, L. A.

2014-12-01

The present study reports the synthesis and morphological, structural and electrochemical characterization of ternary oxides mixture containing nickel, cobalt and tin. The ternary oxide is synthesized by Pechini method with subsequent deposition onto a titanium substrate in a thin-film form. XRD and EDS analysis confirm the formation of ternary film with amorphous nature. SEM analysis show that cracks on the film favor the gain of the surface area that is an interesting feature for electrochemical capacitors. The ternary film is investigated in KOH electrolyte solution using cyclic voltammetry and charge-discharge study with a specific capacitance of 328 F g-1, and a capacitance retention of 86% over 600 cycles. The values of specific power and specific energy was 345.7 W kg-1 and 18.92 Wh kg-1, respectively.

Tailoring the index of refraction of nanocrystalline hafnium oxide thin films

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

Vargas, Mirella; Murphy, N. R.; Ramana, C. V., E-mail: rvchintalapalle@utep.edu

2014-03-10

Hafnium oxide (HfO{sub 2}) films were grown by sputter-deposition by varying the growth temperature (T{sub s} = 25–700 °C). HfO{sub 2} films grown at T{sub s} < 200 °C were amorphous, while those grown at T{sub s} ≥ 200 °C were monoclinic, nanocrystalline with (1{sup ¯}11) texturing. X-ray reflectivity (XRR) analyses indicate that the film-density (ρ) increases with increasing T{sub s}. The index of refraction (n) profiles derived from spectroscopic ellipsometry analyses follow the Cauchy dispersion relation. Lorentz-Lorenz analysis (n{sub (λ)} = 550 nm) and optical-model adopted agree well with the XRR data/analyses. A direct T{sub s}-ρ-n relationship suggests that tailoring the optical quality is possible by tuning T{sub s} and themore » microstructure of HfO{sub 2} films.« less

Effects of surface crystallization and oxidation in nanocrystalline FeNbCuSiB(P) ribbons

NASA Astrophysics Data System (ADS)

Butvinová, B.; Butvin, P.; Brzózka, K.; Kuzminski, M.; Maťko, I.; Švec, P., Sr.; Chromčíková, M.

2017-02-01

Si-poor Fe74Nb3Cu1Si8B14-xPx, (x=0, 3) nanocrystalline ribbon-form alloys often form surfaces, which exert in-plane force on underlying ribbon interior when nanocrystallized in even modest presence of oxygen. Mostly unwanted hard-ribbon-axis magnetic anisotropy is standard result. Essential sources of the surface-caused stress have been sought and influence of P instead of B substitution on this effect was studied too. Preferred surface crystallization (PSC) was found to be the major reason. However P substitution suppresses PSC and promotes Fe-oxide formation, which eases the stress, softens the surfaces and provides different annealing evolution of surface properties.

Tin

USGS Publications Warehouse

Kamilli, Robert J.; Kimball, Bryn E.; Carlin, James F.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

2017-12-19

Tin (Sn) is one of the first metals to be used by humans. Almost without exception, tin is used as an alloy. Because of its hardening effect on copper, tin was used in bronze implements as early as 3500 B.C. The major uses of tin today are for cans and containers, construction materials, transportation materials, and solder. The predominant ore mineral of tin, by far, is cassiterite (SnO2).In 2015, the world’s total estimated mine production of tin was 289,000 metric tons of contained tin. Total world reserves at the end of 2016 were estimated to be 4,700,000 metric tons. China held about 24 percent of the world’s tin reserves and accounted for 38 percent of the world’s 2015 production of tin.The proportion of scrap used in tin production is between 10 and 25 percent. Unlike many metals, tin recycling is relatively efficient, and the fraction of tin in discarded products that get recycled is greater than 50 percent.Only about 20 percent of the world’s identified tin resources occur as primary hydrothermal hard-rock veins, or lodes. These lodes contain predominantly high-temperature minerals and almost invariably occur in close association with silicic, peraluminous granites. About 80 percent of the world’s identified tin resources occur as unconsolidated secondary or placer deposits in riverbeds and valleys or on the sea floor. The largest concentration of both onshore and offshore placers is in the extensive tin belt of Southeast Asia, which stretches from China in the north, through Thailand, Burma (also referred to as Myanmar), and Malaysia, to the islands of Indonesia in the south. Furthermore, tin placers are almost always found closely allied to the granites from which they originate. Other countries with significant tin resources are Australia, Bolivia, and Brazil.Most hydrothermal tin deposits belong to what can be thought of as a superclass of porphyry-greisen deposits. The hydrothermal tin deposits are all characterized by a close spatial

Wrinkle-free graphene electrodes in zinc tin oxide thin-film transistors for large area applications.

PubMed

Lee, Se-Hee; Kim, Jae-Hee; Park, Byeong-Ju; Park, Jozeph; Kim, Hyun-Suk; Yoon, Soon-Gil

2017-02-17

Wrinkle-free graphene was used to form the source-drain electrodes in thin film transistors based on a zinc tin oxide (ZTO) semiconductor. A 10 nm thick titanium adhesion layer was applied prior to transferring a conductive graphene film on top of it by chemical detachment. The formation of an interlayer oxide between titanium and graphene allows the achievement of uniform surface roughness over the entire substrate area. The resulting devices were thermally treated in ambient air, and a substantial decrease in field effect mobility is observed with increasing annealing temperature. The increase in electrical resistivity of the graphene film at higher annealing temperatures may have some influence, however the growth of the oxide interlayer at the ZTO/Ti boundary is suggested to be most influential, thereby inducing relatively high contact resistance.

Wrinkle-free graphene electrodes in zinc tin oxide thin-film transistors for large area applications

NASA Astrophysics Data System (ADS)

Lee, Se-Hee; Kim, Jae-Hee; Park, Byeong-Ju; Park, Jozeph; Kim, Hyun-Suk; Yoon, Soon-Gil

2017-02-01

Wrinkle-free graphene was used to form the source-drain electrodes in thin film transistors based on a zinc tin oxide (ZTO) semiconductor. A 10 nm thick titanium adhesion layer was applied prior to transferring a conductive graphene film on top of it by chemical detachment. The formation of an interlayer oxide between titanium and graphene allows the achievement of uniform surface roughness over the entire substrate area. The resulting devices were thermally treated in ambient air, and a substantial decrease in field effect mobility is observed with increasing annealing temperature. The increase in electrical resistivity of the graphene film at higher annealing temperatures may have some influence, however the growth of the oxide interlayer at the ZTO/Ti boundary is suggested to be most influential, thereby inducing relatively high contact resistance.

Structure and Internal Stress of Tin-Doped Indium Oxide and Indium-Zinc Oxide Films Deposited by DC Magnetron Sputtering

NASA Astrophysics Data System (ADS)

Nishimura, Eriko; Sasabayashi, Tomoko; Ito, Norihiro; Sato, Yasushi; Utsumi, Kentaro; Yano, Koki; Kaijo, Akira; Inoue, Kazuyoshi; Shigesato, Yuzo

2007-12-01

Representative transparent conductive oxide films, such as tin-doped indium oxide (ITO) and indium-zinc oxide (IZO) films, were deposited by dc magnetron sputtering using corresponding oxide targets under various total gas pressures (Ptot) ranging from 0.3 to 3.0 Pa. The ITO films deposited at a Ptot lower than 0.7 Pa were polycrystalline and were found to have a large compressive stress of about 1.5 × 109 Pa, whereas the ITO films deposited at 1.5-3.0 Pa were amorphous and had a low tensile stress. In contrast, all the IZO films deposited at a Ptot range of 0.3-3.0 Pa showed an entirely amorphous structure, where the compressive stress in the IZO films deposited at a Ptot lower than 1.5 Pa was lower than that in the ITO films. Such compressive stress was considered to be generated by the atomic peening effect of high-energy neutrals (Ar0) recoiled from the target or high-energy negative ions (O-) accelerated in the cathode sheath toward the film surface.

Ethylene Gas Sensing Properties of Tin Oxide Nanowires Synthesized via CVD Method

NASA Astrophysics Data System (ADS)

Akhir, Maisara A. M.; Mohamed, Khairudin; Rezan, Sheikh A.; Arafat, M. M.; Haseeb, A. S. M. A.; Uda, M. N. A.; Nuradibah, M. A.

2018-03-01

This paper studies ethylene gas sensing performance of tin oxide (SnO2) nanowires (NWs) as sensing material synthesized using chemical vapor deposition (CVD) technique. The effect of NWs diameter on ethylene gas sensing characteristics were investigated. SnO2 NWs with diameter of ∼40 and ∼240 nm were deposited onto the alumina substrate with printed gold electrodes and tested for sensing characteristic toward ethylene gas. From the finding, the smallest diameter of NWs (42 nm) exhibit fast response and recovery time and higher sensitivity compared to largest diameter of NWs (∼240 nm). Both sensor show good reversibility features for ethylene gas sensor.

Reversible wettability of electron-beam deposited indium-tin-oxide driven by ns-UV irradiation

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

Persano, Luana; Center for Biomolecular Nanotechnologies UNILE, Istituto Italiano di Tecnologia, Via Barsanti, I-73010 Arnesano-LE; Del Carro, Pompilio

2012-04-09

Indium tin oxide (ITO) is one of the most widely used semiconductor oxides in the field of organic optoelectronics, especially for the realization of anode contacts. Here the authors report on the control of the wettability properties of ITO films deposited by reactive electron beam deposition and irradiated by means of nanosecond-pulsed UV irradiation. The enhancement of the surface water wettability, with a reduction of the water contact angle larger than 50 deg., is achieved by few tens of seconds of irradiation. The analyzed photo-induced wettability change is fully reversible in agreement with a surface-defect model, and it can bemore » exploited to realize optically transparent, conductive surfaces with controllable wetting properties for sensors and microfluidic circuits.« less

Interfacial reactions of nano-structured Cu-doped indium oxide/indium tin oxide ohmic contacts to p-GaN.

PubMed

Yoon, Young Joon; Chae, S W; Kim, B K; Park, Min Joo; Kwak, Joon Seop

2010-05-01

Interfacial microstructure and elemental diffusion of Cu-doped indium oxide (CIO)/indium tin oxide (ITO) ohmic contacts to p-type GaN for light-emitting diodes (LEDs) were investigated using cross-sectional transmission electron microscopy (XTEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction. The CIO/ITO contacts gave specific contact resistances of approximately 10(-4) omegacm2 and transmittance greater than 95% at a wavelength of 405 nm when annealed at 630 degrees C for 1 min in air. After annealing at 630 degrees C, multi-component oxides composed of Ga2O3-In2O3, Ga2O3-CuO, and In2O3-CuO formed at the interface between p-GaN and ITO. Formation of multi-component oxides reduced the barrier height between p-GaN and ITO due to their higher work functions than that of ITO, and caused Ga in the GaN to diffuse into the CIO/ITO layer, followed by generation of acceptor-like Ga vacancies near the GaN surface, which lowered contact resistivity of the CIO/ITO contacts to p-GaN after the annealing.

Enhanced diode characteristics of organic solar cell with silanized fluorine doped tin oxide electrode

NASA Astrophysics Data System (ADS)

Sachdeva, Sheenam; Sharma, Sameeksha; Singh, Devinder; Tripathi, S. K.

2018-05-01

To investigate the diode characteristics of organic solar cell based on the planar heterojunction of 4,4'- cyclohexylidenebis[N,N-bis(4-methylphenyl)benzenamine] (TAPC) and fullerene (C70), we report the use of silanized fluorine-doped tin oxide (FTO) anode with N1-(3-trimethoxysilylpropyl)diethyltriamine (DETA) forming monolayer. The use of silanized FTO results in the decrease of saturation current density and diode ideality factor of the device. Such silanized FTO anode is found to enhance the material quality and improve the device properties.

Oxidation of Hydrocarbons on the Surface of Tin Dioxide Chemical Sensors

PubMed Central

Teterycz, Helena; Halek, Patryk; Wiśniewski, Kamil; Halek, Grzegorz; Koźlecki, Tomasz; Polowczyk, Izabela

2011-01-01

The paper presents the results of our investigation on the effect of the molecular structure of organic vapors on the characteristics of resistive chemical gas sensors. The sensors were based on tin dioxide and prepared by means of thick film technology. The electrical and catalytic examinations showed that the abstraction of two hydrogen atoms from the organic molecule and formation of a water in result of reaction with a chemisorbed oxygen ion, determine the rate of oxidation reactions, and thus the sensor performance. The rate of the process depends on the order of carbon atoms and Lewis acidity of the molecule. Therefore, any modification of the surface centers of a sensor material, modifies not only the sensor sensitivity, but also its selectivity. PMID:22163855

Multiple electron injection dynamics in linearly-linked two dye co-sensitized nanocrystalline metal oxide electrodes for dye-sensitized solar cells.

PubMed

Shen, Qing; Ogomi, Yuhei; Park, Byung-wook; Inoue, Takafumi; Pandey, Shyam S; Miyamoto, Akari; Fujita, Shinsuke; Katayama, Kenji; Toyoda, Taro; Hayase, Shuzi

2012-04-07

Understanding the electron transfer dynamics at the interface between dye sensitizer and semiconductor nanoparticle is very important for both a fundamental study and development of dye-sensitized solar cells (DSCs), which are a potential candidate for next generation solar cells. In this study, we have characterized the ultrafast photoexcited electron dynamics in a newly produced linearly-linked two dye co-sensitized solar cell using both a transient absorption (TA) and an improved transient grating (TG) technique, in which tin(IV) 2,11,20,29-tetra-tert-butyl-2,3-naphthalocyanine (NcSn) and cis-diisothiocyanato-bis(2,2'-bipyridyl-4,4'-dicarboxylato)ruthenium(II) bis(tetrabutylammonium) (N719) are molecularly and linearly linked and are bonded to the surface of a nanocrystalline tin dioxide (SnO(2)) electrode by a metal-O-metal linkage (i.e. SnO(2)-NcSn-N719). By comparing the TA and TG kinetics of NcSn, N719, and hybrid NcSn-N719 molecules adsorbed onto both of the SnO(2) and zirconium dioxide (ZrO(2)) nanocrystalline films, the forward and backward electron transfer dynamics in SnO(2)-NcSn-N719 were clarified. We found that there are two pathways for electron injection from the linearly-linked two dye molecules (NcSn-N719) to SnO(2). The first is a stepwise electron injection, in which photoexcited electrons first transfer from N719 to NcSn with a transfer time of 0.95 ps and then transfer from NcSn to the conduction band (CB) of SnO(2) with two timescales of 1.6 ps and 4.2 ps. The second is direct photoexcited electron transfer from N719 to the CB of SnO(2) with a timescale of 20-30 ps. On the other hand, back electron transfer from SnO(2) to NcSn is on a timescale of about 2 ns, which is about three orders of magnitude slower compared to the forward electron transfer from NcSn to SnO(2). The back electron transfer from NcSn to N719 is on a timescale of about 40 ps, which is about one order slower compared to the forward electron transfer from N719 to Nc

Fundamental electrochemiluminescence characteristics of fluorine-doped tin oxides synthesized by sol-gel combustion.

PubMed

Moon, B H; Chaoumead, A; Sung, Y M

2013-10-01

Fluorine-doped tin oxide (FTO) materials synthesized by sol-gel combustion method were investigated for electrochemical luminescence (ECL) application. Effects of sol-gel combustion conditions on the structures and morphology of the porous FTO (p-FTO) materials were studied. ECL efficiency of p-FTO-based cell was about 251 cd/m2 at 4 V bias, which is higher than the sell using only FTO electrodes (102.8 cd/m2). The highest intensity of the emitting light was obtained at the wavelength of about 610 nm. The porous FTO layer was effective for increasing ECL intensities.

Production of nanocrystalline metal powders via combustion reaction synthesis

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

Frye, John G.; Weil, Kenneth Scott; Lavender, Curt A.

Nanocrystalline metal powders comprising tungsten, molybdenum, rhenium and/or niobium can be synthesized using a combustion reaction. Methods for synthesizing the nanocrystalline metal powders are characterized by forming a combustion synthesis solution by dissolving in water an oxidizer, a fuel, and a base-soluble, ammonium precursor of tungsten, molybdenum, rhenium, or niobium in amounts that yield a stoichiometric burn when combusted. The combustion synthesis solution is then heated to a temperature sufficient to substantially remove water and to initiate a self-sustaining combustion reaction. The resulting powder can be subsequently reduced to metal form by heating in a reducing gas environment.

Chemical stability and electrical performance of dual-active-layered zinc-tin-oxide/indium-gallium-zinc-oxide thin-film transistors using a solution process.

PubMed

Kim, Chul Ho; Rim, You Seung; Kim, Hyun Jae

2013-07-10

We investigated the chemical stability and electrical properties of dual-active-layered zinc-tin-oxide (ZTO)/indium-gallium-zinc-oxide (IGZO) structures (DALZI) with the durability of the chemical damage. The IGZO film was easily corroded or removed by an etchant, but the DALZI film was effectively protected by the high chemical stability of ZTO. Furthermore, the electrical performance of the DALZI thin-film transistor (TFT) was improved by densification compared to the IGZO TFT owing to the passivation of the pin holes or pore sites and the increase in the carrier concentration due to the effect of Sn(4+) doping.

Tin-oxide-coated single-walled carbon nanotube bundles supporting platinum electrocatalysts for direct ethanol fuel cells.

PubMed

Hsu, Ryan S; Higgins, Drew; Chen, Zhongwei

2010-04-23

Novel tin-oxide (SnO(2))-coated single-walled carbon nanotube (SWNT) bundles supporting platinum (Pt) electrocatalysts for ethanol oxidation were developed for direct ethanol fuel cells. SnO(2)-coated SWNT (SnO(2)-SWNT) bundles were synthesized by a simple chemical-solution route. SnO(2)-SWNT bundles supporting Pt (Pt/SnO(2)-SWNTs) electrocatalysts and SWNT-supported Pt (Pt/SWNT) electrocatalysts were prepared by an ethylene glycol reduction method. The catalysts were physically characterized using TGA, XRD and TEM and electrochemically evaluated through cyclic voltammetry experiments. The Pt/SnO(2)-SWNTs showed greatly enhanced electrocatalytic activity for ethanol oxidation in acid medium, compared to the Pt/SWNT. The optimal SnO(2) loading of Pt/SnO(2)-SWNT catalysts with respect to specific catalytic activity for ethanol oxidation was also investigated.

Structural & oxidation behavior of TiN & AlxTi1-xN coatings deposited by CA-PVD technique

NASA Astrophysics Data System (ADS)

Thorat, Nirmala; Mundotia, Rajesh; Varma, Ranjana; Kale, Ashwin; Mhatre, Umesh; Patel, Nainesh

2018-04-01

Coatings with thermal stability at elevated temperatures are prerequisite for various high speed machining and high temperature applications. The present work compares the oxidation behavior of the AlxTi1-xN coating prepared with different Al composition. Coated samples were tested at different temperatures in the range of 400 - 800 C to study their oxidation behavior. Percentage weight gain of all the samples were evaluated using high accuracy weighing balance. The depth of oxide layers were studied using Calo-test instrument. The XRD analysis was carried out to specify the phase structure. Higher oxidation rate was observed for TiN coating at all the oxidation temperatures. Oxidation rate was higher for Al13Ti87N and Al70Ti30N coatings compared to Al60Ti40N and Al50Ti50N coatings which exhibits better oxygen diffusion barrier at all the temperature.

Nanocrystalline ceramic materials

DOEpatents

Siegel, Richard W.; Nieman, G. William; Weertman, Julia R.

1994-01-01

A method for preparing a treated nanocrystalline metallic material. The method of preparation includes providing a starting nanocrystalline metallic material with a grain size less than about 35 nm, compacting the starting nanocrystalline metallic material in an inert atmosphere and annealing the compacted metallic material at a temperature less than about one-half the melting point of the metallic material.

Large-scale fabrication of single crystalline tin nanowire arrays

NASA Astrophysics Data System (ADS)

Luo, Bin; Yang, Dachi; Liang, Minghui; Zhi, Linjie

2010-09-01

Large-scale single crystalline tin nanowire arrays with preferred lattice orientation along the [100] direction were fabricated in porous anodic aluminium oxide (AAO) membranes by the electrodeposition method using copper nanorod as a second electrode.Large-scale single crystalline tin nanowire arrays with preferred lattice orientation along the [100] direction were fabricated in porous anodic aluminium oxide (AAO) membranes by the electrodeposition method using copper nanorod as a second electrode. Electronic supplementary information (ESI) available: Experimental details and the information for single crystalline copper nanorods. See DOI: 10.1039/c0nr00206b

Study of Degradation Kinetics of Parathion Methyl On Mixed Nanocrystalline Titania-Zirconium and Titania-Cerium Oxides

NASA Astrophysics Data System (ADS)

Kuráň, Pavel; Pšenička, Martin; Šťastný, Martin; Benkocká, Monika; Janoš, Pavel

2016-10-01

The unique surface properties of some nanocrystalline metal oxides and their application for removal of various toxic compounds were reported in early 1990s. Recently, a reliable method for the preparation of reactive cerium dioxide sorbent and its application for degradation of the organophosphate pesticides, such as parathion methyl, chlorpyrifos, dichlofenthion, fenchlorphos, and prothiofos, as well as of some chemical warfare agents-nerve gases soman and O-ethyl S-[2-(diisopropylamino) ethyl] methylphosphonothioate (VX) was published. This paper reports on the kinetics study of degradation of parathion methyl as a representative organophosphate on nanocrystalline metal oxides TiO2, ZrO2, CeO2 and their mixtures in different molar ratios of particular elements. The tested sorbents except of CeO2 were prepared by different methods (e.g. sol-gel, precipitation) in cooperation with Institute of Inorganic Chemistry (Rez, Czech Republic). The degradation kinetics of parathion methyl on tested sorbents was followed by HPLC equipped with diode array detector. The basic kinetics parameters (half-lives of parathion methyl degradation, rate constants of degradation product formation) were calculated for each sorbent from Weber-Morris equation of 1st order diffusion kinetic model. The results proved the ability of prepared sorbents to degrade parathion methyl under formation of 4-nitrophenol as the main degradation product. The most efficient sorbents were TiCe (2:8), TiCe (1:1), TiCe (0:1) (50-70 %) followed by TiZr (1:1), TiCe (8:2), TiZr (8:2), TiZr (2:8) (20-30%) and TiO2, ZrO2 (less than 5 %).

Fabrication of large-scale ripples on fluorine-doped tin oxide films by femtosecond laser irradiation

NASA Astrophysics Data System (ADS)

Han, Yan-Hua; Li, Yan; Zhao, Xiu-Li; Qu, Shi-Liang

2014-09-01

The large-scale uniform self-organized ripples are fabricated on fluorine-doped tin oxide (FTO) coated glass by femtosecond laser. They can be smoothly linked in a horizontal line with the moving of XYZ stage by setting its velocity and the repetition rate of the laser. The ripple-to-ripple linking can also be realized through line-by-line scanning on a vertical level. The mechanism analysis shows that the seeding effect plays a key role in the linking of ripples.

Nanocrystalline ceramic materials

DOEpatents

Siegel, R.W.; Nieman, G.W.; Weertman, J.R.

1994-06-14

A method is disclosed for preparing a treated nanocrystalline metallic material. The method of preparation includes providing a starting nanocrystalline metallic material with a grain size less than about 35 nm, compacting the starting nanocrystalline metallic material in an inert atmosphere and annealing the compacted metallic material at a temperature less than about one-half the melting point of the metallic material. 19 figs.

Role of point defects and HfO2/TiN interface stoichiometry on effective work function modulation in ultra-scaled complementary metal-oxide-semiconductor devices

NASA Astrophysics Data System (ADS)

Pandey, R. K.; Sathiyanarayanan, Rajesh; Kwon, Unoh; Narayanan, Vijay; Murali, K. V. R. M.

2013-07-01

We investigate the physical properties of a portion of the gate stack of an ultra-scaled complementary metal-oxide-semiconductor (CMOS) device. The effects of point defects, such as oxygen vacancy, oxygen, and aluminum interstitials at the HfO2/TiN interface, on the effective work function of TiN are explored using density functional theory. We compute the diffusion barriers of such point defects in the bulk TiN and across the HfO2/TiN interface. Diffusion of these point defects across the HfO2/TiN interface occurs during the device integration process. This results in variation of the effective work function and hence in the threshold voltage variation in the devices. Further, we simulate the effects of varying the HfO2/TiN interface stoichiometry on the effective work function modulation in these extremely-scaled CMOS devices. Our results show that the interface rich in nitrogen gives higher effective work function, whereas the interface rich in titanium gives lower effective work function, compared to a stoichiometric HfO2/TiN interface. This theoretical prediction is confirmed by the experiment, demonstrating over 700 meV modulation in the effective work function.

Non-hydrolytic Sol-gel Synthesis of Tin Sulfides

NASA Astrophysics Data System (ADS)

Kaur, Rajvinder

The non-hydrolytic sol-gel (NHSG) process is an effective low temperature route well known for preparing homogeneous metal oxides. Thermodynamically as well as kinetically favored products, which cannot be prepared with the traditional solid-state routes, can be produced using NHSG. This project is focused on the exploration of NHSG synthesis of binary tin sulfides. In the past few years, metal sulfides have been the subject of significant interest. Much effort has been devoted to understand these materials because of their potential applications in electronic, optical, and superconductor devices.4 Among these materials, tin sulfides are materials of technological importance, which are being explored as semiconductors, anode materials for Li ion batteries, photoconductors, photocatalysts and absorber layer materials in photovoltaic solar cell devices. All of these applications depend upon features like homogeneity, oxidation state, high surface area and purity of the materials. These properties can be difficult to achieve by employing traditional synthetic routes, which require high temperatures due to slow diffusion, limiting the products to thermodynamically stable phases and prohibiting control over properties like particle size and surface area. A variety of low temperature methods are being explored due to the increased demand for such advanced materials. This project is focused on exploring the NHSG approach to synthesize binary tin sulfides, with the main goal of establishing conditions for the targeted synthesis of different tin sulfide polymorphs with controlled particle size. Being non-oxide materials, tin sulfides can be air sensitive, which requires special attention in handling. All reactions were carried out in absence of oxygen. This project explores the reaction of tin halides with thioethers in a dry solvent medium, leading to the formation of tin sulfides. There are a number of synthetic parameters that can be varied for the NHSG approach. A

Improvement of Bipolar Switching Properties of Gd:SiOx RRAM Devices on Indium Tin Oxide Electrode by Low-Temperature Supercritical CO2 Treatment.

PubMed

Chen, Kai-Huang; Chang, Kuan-Chang; Chang, Ting-Chang; Tsai, Tsung-Ming; Liang, Shu-Ping; Young, Tai-Fa; Syu, Yong-En; Sze, Simon M

2016-12-01

Bipolar switching resistance behaviors of the Gd:SiO2 resistive random access memory (RRAM) devices on indium tin oxide electrode by the low-temperature supercritical CO2-treated technology were investigated. For physical and electrical measurement results obtained, the improvement on oxygen qualities, properties of indium tin oxide electrode, and operation current of the Gd:SiO2 RRAM devices were also observed. In addition, the initial metallic filament-forming model analyses and conduction transferred mechanism in switching resistance properties of the RRAM devices were verified and explained. Finally, the electrical reliability and retention properties of the Gd:SiO2 RRAM devices for low-resistance state (LRS)/high-resistance state (HRS) in different switching cycles were also measured for applications in nonvolatile random memory devices.

Investigation of tin oxide nanofibers synthesized via bio-template technique

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

Kundu, Virender Singh, E-mail: vskundu-kuk@rediffmail.com; Dhiman, Jonny; Kumar, Suresh

In the present paper tin oxide nanofibers have been by synthesized using cotton as bio-template via sol-gel route. This is comparatively a new synthesis technique. The structure and morphology of the obtained SnO{sub 2} nanofibers were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX). The optical properties of the same have been studied by using UV-Vis spectroscopy. The observed XRD pattern showed that peaks are very narrow and sharp which indicates crystalline nature of samples. SEM images gave an idea about the sample morphology and confirm that the obtained sample were nanofibers. The optical absorbancemore » spectrum of the sample under study was recorded in UV-visible region (200nm- 800nm). The band gap of the sample was found to be 3.95 eV which is higher than their bulk counterpart.« less

Polymer blend of PLA/PHBV based bionanocomposites reinforced with nanocrystalline cellulose for potential application as packaging material.

PubMed

Dasan, Y K; Bhat, A H; Ahmad, Faiz

2017-02-10

The current research discusses the development of poly (lactic acid) (PLA) and poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) reinforced nanocrystalline cellulose bionanocomposites. The nanocrystalline cellulose was derived from waste oil palm empty fruit bunch fiber by acid hydrolysis process. The resulting nanocrystalline cellulose suspension was then surface functionalized by TEMPO-mediated oxidation and solvent exchange process. Furthermore, the PLA/PHBV/nanocrystalline cellulose bionanocomposites were produced by solvent casting method. The effect of the addition of nanocrystalline cellulose on structural, morphology, mechanical and barrier properties of bionanocomposites was investigated. The results revealed that the developed bionanocomposites showed improved mechanical properties and decrease in oxygen permeability rate. Therefore, the developed bio-based composite incorporated with an optimal composition of nanocrystalline cellulose exhibits properties as compared to the polymer blend. Copyright © 2016 Elsevier Ltd. All rights reserved.

Swift heavy ion induced modification in morphological and physico-chemical properties of tin oxide nanocomposites

NASA Astrophysics Data System (ADS)

Jaiswal, Manoj Kumar; Kanjilal, D.; Kumar, Rajesh

2013-11-01

Nanocomposite thin films of tin oxide (SnO2)/titanium oxide (TiO2) were grown on silicon (1 0 0) substrates by electron beam evaporation deposition technique using sintered nanocomposite pellet of SnO2/TiO2 in the percentage ratio of 95:5. Sintering of the nanocomposite pellet was done at 1300 °C for 24 h. The thicknesses of these films were measured to be 100 nm during deposition using piezo-sensor attached to the deposition chamber. TiO2 doped SnO2 nanocomposite films were irradiated by 100 MeV Au8+ ion beam at fluence range varying from 1 × 1011 ions/cm2 to 5 × 1013 ions/cm2 at Inter University Accelerator Center (IUAC), New Delhi, India. Chemical properties of pristine and ion irradiation modified thin films were characterized by Fourier Transform Infrared (FTIR) spectroscopy. FTIR peak at 610 cm-1 confirms the presence of O-Sn-O bridge of tin (IV) oxide signifying the composite nature of pristine and irradiated thin films. Atomic Force Microscope (AFM) in tapping mode was used to study the surface morphology and grain growth due to swift heavy ion irradiation at different fluencies. Grain size calculations obtained from sectional analysis of AFM images were compared with results obtained from Glancing Angle X-ray Diffraction (GAXRD) measurements using Scherrer’s formulae. Phase transformation due to irradiation was observed from Glancing Angle X-ray Diffraction (GAXRD) results. The prominent 2θ peaks observed in GAXRD spectrum are at 30.67°, 32.08°, 43.91°, 44.91° and 52.35° in the irradiated films.

The influence of visible light on transparent zinc tin oxide thin film transistors

NASA Astrophysics Data System (ADS)

Görrn, P.; Lehnhardt, M.; Riedl, T.; Kowalsky, W.

2007-11-01

The characteristics of transparent zinc tin oxide thin film transistors (TTFTs) upon illumination with visible light are reported. Generally, a reversible decrease of threshold voltage Vth, saturation field effect mobility μsat, and an increase of the off current are found. The time scale of the recovery in the dark is governed by the persistent photoconductivity in the semiconductor. Devices with tuned [Zn]:[Sn] ratio show a shift of Vth of less 2V upon illumination at 5mW/cm2 (brightness >30000cd/m2) throughout the visible spectrum. These results demonstrate TTFTs which are candidates as pixel drivers in transparent active-matrix organic light emitting diode displays.

Electron microscopic and ion scattering studies of heteroepitaxial tin-doped indium oxide films

NASA Astrophysics Data System (ADS)

Kamei, Masayuki; Shigesato, Yuzo; Takaki, Satoru; Hayashi, Yasuo; Sasaki, Mikio; Haynes, Tony E.

1994-08-01

The microstructure of heteroepitaxial tin-doped indium oxide (ITO) films were studied in detail. The surface morphology of the heteroepitaxial ITO film consisted of square-shaped, in-plane oriented subgrains (˜300 Å) in contrast to that of the polycrystalline film (characteristic grain-subgrain structure). The subgrain boundaries were predominantly formed along the {110} planes in the ITO film and dislocations were observed primarily along the subgrain boundaries. Ion channeling measurements showed the dislocation density of this film to be approximately 3×1010/cm2, and the angular distribution of the ion channeling yield showed that the subgrains are aligned to within better than 0.3° (standard deviation).

Heteroepitaxial growth of tin-doped indium oxide films on single crystalline yttria stabilized zirconia substrates

NASA Astrophysics Data System (ADS)

Kamei, Masayuki; Yagami, Teruyuki; Takaki, Satoru; Shigesato, Yuzo

1994-05-01

Heteroepitaxial growth of tin-doped indium oxide (ITO) film was achieved for the first time by using single crystalline yttria stabilized zirconia (YSZ) as substrates. The epitaxial relationship between ITO film and YSZ substrate was ITO[100]∥YSZ[100]. By comparing the electrical properties of this epitaxial ITO film with that of a randomly oriented polycrystalline ITO film grown on a glass substrate, neither the large angle grain boundaries nor the crystalline orientation were revealed to be dominant in determining the carrier mobility in ITO films.

Anisotropic optical transmission of femtosecond laser induced periodic surface nanostructures on indium-tin-oxide films.

PubMed

Wang, Chih; Wang, Hsuan-I; Luo, Chih-Wei; Leu, Jihperng

2012-09-03

Two types of periodic nanostructures, self-organized nanodots and nanolines, were fabricated on the surfaces of indium-tin-oxide (ITO) films using femtosecond laser pulse irradiation. Multiple periodicities (approximately 800 nm and 400 nm) were clearly observed on the ITO films with nanodot and nanoline structures and were identified using two-dimensional Fourier transformation patterns. Both nanostructures show the anisotropic transmission characteristics in the visible range, which are strongly correlated with the geometry and the metallic content of the laser-induced nanostructures.

Anisotropic optical transmission of femtosecond laser induced periodic surface nanostructures on indium-tin-oxide films

PubMed Central

Wang, Chih; Wang, Hsuan-I; Luo, Chih-Wei; Leu, Jihperng

2012-01-01

Two types of periodic nanostructures, self-organized nanodots and nanolines, were fabricated on the surfaces of indium-tin-oxide (ITO) films using femtosecond laser pulse irradiation. Multiple periodicities (approximately 800 nm and 400 nm) were clearly observed on the ITO films with nanodot and nanoline structures and were identified using two-dimensional Fourier transformation patterns. Both nanostructures show the anisotropic transmission characteristics in the visible range, which are strongly correlated with the geometry and the metallic content of the laser-induced nanostructures. PMID:23066167

Synthesis of nanocrystalline Ni/Ce-YSZ powder via a polymerization route

NASA Astrophysics Data System (ADS)

Abolghasemi, Z.; Tamizifar, M.; Arzani, K.; Nemati, A.; Khanfekr, A.; Bolandi, M.

2013-08-01

Pechini process was used for preparation of three kinds of nanocrystalline powders of yttria-stabilized zirconia (YSZ): doped with 1.5 mol% nickel oxide, doped with 15 mol% ceria, and doped with 1.5 mol% nickel oxide plus 15 mol% ceria. Zirconium chloride, yttrium nitrate, cerium nitrate, nickel nitrate, citric acid and ethylene glycol were polymerized at 80 °C to produce a gel. XRD, SEM and TEM analyses were used to investigate the crystalline phases and microstructures of obtained compounds. The results of XRD revealed the formation of nanocrystalline powder at 900 °C. Morphology of the powder calcined at 900 °C, examined with a scanning electron microscope, showed that the presence of nickel and cerium inhibited the grain growth in the system. The average crystallite size of the material doped with nickel oxide (9.33 nm) was bigger than the one doped with cerium oxide (9.29 nm), while the YSZ doping with the two oxides simultaneously promoted the grain growth with crystallite size of 11.37 nm. Yttria-stabilized zirconia powder with a mean crystallite size of 9.997 nm was prepared successfully by this method.

Optical and electrical properties of indium tin oxide films near their laser damage threshold [Electrical and optical properties of indium tin oxide films under multi-pulse laser irradiation at 1064 nm

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

Yoo, Jae -Hyuck; Lange, Andrew; Bude, Jeff

In this paper, we investigated whether the optical and electrical properties of indium tin oxide (ITO) films are degraded under laser irradiation below their laser ablation threshold. While performing multi-pulse laser damage experiments on a single ITO film (4.7 ns, 1064 nm, 10 Hz), we examined the optical and electrical properties in situ. A decrease in reflectance was observed prior to laser damage initiation. However, under sub-damage threshold irradiation, conductivity and reflectance of the film were maintained without measurable degradation. This indicates that ITO films in optoelectronic devices may be operated below their lifetime laser damage threshold without noticeable performancemore » degradation.« less

Optical and electrical properties of indium tin oxide films near their laser damage threshold [Electrical and optical properties of indium tin oxide films under multi-pulse laser irradiation at 1064 nm

DOE PAGES

Yoo, Jae -Hyuck; Lange, Andrew; Bude, Jeff; ...

2017-02-10

In this paper, we investigated whether the optical and electrical properties of indium tin oxide (ITO) films are degraded under laser irradiation below their laser ablation threshold. While performing multi-pulse laser damage experiments on a single ITO film (4.7 ns, 1064 nm, 10 Hz), we examined the optical and electrical properties in situ. A decrease in reflectance was observed prior to laser damage initiation. However, under sub-damage threshold irradiation, conductivity and reflectance of the film were maintained without measurable degradation. This indicates that ITO films in optoelectronic devices may be operated below their lifetime laser damage threshold without noticeable performancemore » degradation.« less

Optical second harmonic generation phase measurement at interfaces of some organic layers with indium tin oxide

NASA Astrophysics Data System (ADS)

Ngah Demon, Siti Zulaikha; Miyauchi, Yoshihiro; Mizutani, Goro; Matsushima, Toshinori; Murata, Hideyuki

2014-08-01

We observed phase shift in optical second harmonic generation (SHG) from interfaces of indium tin oxide (ITO)/copper phthalocyanine (CuPc) and ITO/pentacene. Phase correction due to Fresnel factors of the sample was taken into account. The phase of SHG electric field at the ITO/pentacene interface, ϕinterface with respect to the phase of SHG of bare substrate ITO was 160°, while the interface of ITO/CuPc had a phase of 140°.

Nanocrystal floating gate memory with solution-processed indium-zinc-tin-oxide channel and colloidal silver nanocrystals

NASA Astrophysics Data System (ADS)

Hu, Quanli; Ha, Sang-Hyub; Lee, Hyun Ho; Yoon, Tae-Sik

2011-12-01

A nanocrystal (NC) floating gate memory with solution-processed indium-zinc-tin-oxide (IZTO) channel and silver (Ag) NCs embedded in thin gate dielectric layer (SiO2(30 nm)/Al2O3(3 nm)) was fabricated. Both the IZTO channel and colloidal Ag NC layers were prepared by spin-coating and subsequent annealing, and dip-coating process, respectively. A threshold voltage shift up to ~0.9 V, corresponding to the electron density of 6.5 × 1011 cm-2, at gate pulsing <=10 V was achieved by the charging of high density NCs. These results present the successful non-volatile memory characteristics of an oxide-semiconductor transistor fabricated through solution processes.

Size-dependent electronic structure controls activity for ethanol electro-oxidation at Ptn/indium tin oxide (n = 1 to 14).

PubMed

von Weber, Alexander; Baxter, Eric T; Proch, Sebastian; Kane, Matthew D; Rosenfelder, Michael; White, Henry S; Anderson, Scott L

2015-07-21

Understanding the factors that control electrochemical catalysis is essential to improving performance. We report a study of electrocatalytic ethanol oxidation - a process important for direct ethanol fuel cells - over size-selected Pt centers ranging from single atoms to Pt14. Model electrodes were prepared by soft-landing of mass-selected Ptn(+) on indium tin oxide (ITO) supports in ultrahigh vacuum, and transferred to an in situ electrochemical cell without exposure to air. Each electrode had identical Pt coverage, and differed only in the size of Pt clusters deposited. The small Ptn have activities that vary strongly, and non-monotonically with deposited size. Activity per gram Pt ranges up to ten times higher than that of 5 to 10 nm Pt particles dispersed on ITO. Activity is anti-correlated with the Pt 4d core orbital binding energy, indicating that electron rich clusters are essential for high activity.

Application of argon atmospheric cold plasma for indium tin oxide (ITO) based diodes

NASA Astrophysics Data System (ADS)

Akbari Nia, S.; Jalili, Y. Seyed; Salar Elahi, A.

2017-09-01

Transparent Conductive Oxide (TCO) layers due to transparency, high conductivity and hole injection capability have attracted a lot of attention. One of these layers is Indium Tin Oxide (ITO). ITO due to low resistance, transparency in the visible spectrum and its proper work function is widely used in the manufacture of organic light emitting diodes and solar cells. One way for improving the ITO surface is plasma treatment. In this paper, changes in surface morphology, by applying argon atmospheric pressure cold plasma, was studied through Atomic Force Microscopic (AFM) image analysis and Fourier Transform Infrared Spectroscopy (FTIR) analysis. FTIR analysis showed functional groups were not added or removed, but chemical bond angle and bonds strength on the surface were changed and also AFM images showed that surface roughness was increased. These factors lead to the production of diodes with enhanced Ohmic contact and injection mechanism which are more appropriate in industrial applications.

Tunable infrared hyperbolic metamaterials with periodic indium-tin-oxide nanorods

DOE PAGES

Guo, Peijun; Chang, Robert P. H.; Schaller, Richard D.

2017-07-10

Hyperbolic metamaterials (HMMs) are artificially engineered optical media that have been used for light confinement, excited state decay rate engineering, and subwavelength imaging, due to their highly anisotropic permittivity and with it the capability of supporting high- k modes. HMMs in the infrared range can be conceived for additional applications such as free space communication, thermal engineering, and molecular sensing. Here, we demonstrate infrared HMMs comprised of periodic indium-tin-oxide nanorod arrays (ITO-NRAs). We show that the ITO-NRA based HMMs exhibit a stationary epsilon-near-pole resonance in the near-infrared regime that is insensitive to the filling ratio, and a highly tunable epsilon-near-zeromore » resonance in the mid-infrared range depending on the array periodicity. Experimental results are supported by finite-element simulations, in which the ITO-NRAs are treated both explicitly and as an effective hyperbolic media. Lastly, our work presents a low-loss HMM platform with favorable spectral tunability in the infrared range.« less

Stabilized TiN nanowire arrays for high-performance and flexible supercapacitors.

PubMed

Lu, Xihong; Wang, Gongming; Zhai, Teng; Yu, Minghao; Xie, Shilei; Ling, Yichuan; Liang, Chaolun; Tong, Yexiang; Li, Yat

2012-10-10

Metal nitrides have received increasing attention as electrode materials for high-performance supercapacitors (SCs). However, most of them are suffered from poor cycling stability. Here we use TiN as an example to elucidate the mechanism causing the capacitance loss. X-ray photoelectron spectroscopy analyses revealed that the instability is due to the irreversible electrochemical oxidation of TiN during the charging/discharging process. Significantly, we demonstrate for the first time that TiN can be stabilized without sacrificing its electrochemical performance by using poly(vinyl alcohol) (PVA)/KOH gel as the electrolyte. The polymer electrolyte suppresses the oxidation reaction on electrode surface. Electrochemical studies showed that the TiN solid-state SCs exhibit extraordinary stability up to 15,000 cycles and achieved a high volumetric energy density of 0.05 mWh/cm(3). The capability of effectively stabilizing nitride materials could open up new opportunities in developing high-performance and flexible SCs.

Mechanical properties of nanocrystalline cobalt

NASA Astrophysics Data System (ADS)

Karimpoor, Amir A.; Erb, Uwe

2006-05-01

Due to their excellent wear and corrosion properties, nanocrystalline cobalt and several cobalt alloys made by electrodeposition are currently being developed as environmentally benign replacement coatings for hard chromium electrodeposits. The focus of this study is on the mechanical properties of nanocrystalline cobalt, which are currently not well understood. A comparison is presented for hardness, tensile properties, Charpy impact properties and fracture surface analysis of both nanocrystalline (grain size: 12 nm) and conventional polycrystalline (grain size: 4.8 m) cobalt. It is shown that the hardness and tensile strength of nanocrystalline cobalt is 2-3 times higher than for polycrystalline cobalt. However, in contrast to other nanocrystalline materials tested previously, nanocrystalline cobalt retains considerable ductility with elongation to fracture values up to 7%.

Indium oxide co-doped with tin and zinc: A simple route to highly conducting high density targets for TCO thin-film fabrication

NASA Astrophysics Data System (ADS)

Saadeddin, I.; Hilal, H. S.; Decourt, R.; Campet, G.; Pecquenard, B.

2012-07-01

Indium oxide co-doped with tin and zinc (ITZO) ceramics have been successfully prepared by direct sintering of the powders mixture at 1300 °C. This allowed us to easily fabricate large highly dense target suitable for sputtering transparent conducting oxide (TCO) films, without using any cold or hot pressing techniques. Hence, the optimized ITZO ceramic reaches a high relative bulk density (˜ 92% of In2O3 theoretical density) and higher than the well-known indium oxide doped with tin (ITO) prepared under similar conditions. All X-ray diagrams obtained for ITZO ceramics confirms a bixbyte structure typical for In2O3 only. This indicates a higher solubility limit of Sn and Zn when they are co-doped into In2O3 forming a solid-solution. A very low value of electrical resistivity is obtained for [In2O3:Sn0.10]:Zn0.10 (1.7 × 10-3 Ω cm, lower than ITO counterpart) which could be fabricated to high dense ceramic target suing pressure-less sintering.

Structural, electrical and optical properties of indium tin oxide thin film grown by metal organic chemical vapor deposition with tetramethyltin-precursor

NASA Astrophysics Data System (ADS)

Zhuo, Yi; Chen, Zimin; Tu, Wenbin; Ma, Xuejin; Wang, Gang

2018-01-01

Tin-doped indium oxide (ITO) is grown by metal organic chemical vapor deposition (MOCVD) using tetramethyltin (TDMASn) as tin precursor. The as-grown ITO films are polycrystalline with (111) and (100) textures. A gradual transition of crystallographic orientation from (111) preferred to (100) preferred is observed as the composition of tin changes. By precisely controlling the Sn doping, the ITO thin films present promising optical and electrical performances at either near-infrared-visible or visible-near-ultraviolet ranges. At low Sn doping level, the as-grown ITO possesses high electron mobility of 48.8 cm2 V-1 s-1, which results in high near-infrared transmittance and low resistivity. At higher Sn doping level, high carrier concentration (8.9 × 1020 cm-3) and low resistivity (3 × 10-4 Ω cm) are achieved. The transmittance is 97.8, 99.1, and 82.3% at the wavelength of 550, 365, and 320 nm, respectively. The results strongly suggest that MOCVD with TDMASn as tin precursor is an effective method to fabricate high quality ITO thin film for near-infrared, visible light, and near-ultraviolet application.

Method of fabricating conducting oxide-silicon solar cells utilizing electron beam sublimation and deposition of the oxide

DOEpatents

Feng, Tom; Ghosh, Amal K.

1979-01-01

In preparing tin oxide and indium tin oxide-silicon heterojunction solar cells by electron beam sublimation of the oxide and subsequent deposition thereof on the silicon, the engineering efficiency of the resultant cell is enhanced by depositing the oxide at a predetermined favorable angle of incidence. Typically the angle of incidence is between 40.degree. and 70.degree. and preferably between 55.degree. and 65.degree. when the oxide is tin oxide and between 40.degree. and 70.degree. when the oxide deposited is indium tin oxide. gi The Government of the United States of America has rights in this invention pursuant to Department of Energy Contract No. EY-76-C-03-1283.

Electrical Conducting and Mechanism of Oxygen-Deficient Tin Oxide Films Deposited by RF Magnetron Sputtering at Various O2/Ar Ratios

NASA Astrophysics Data System (ADS)

Wang, Qi; Wang, Chengbiao; Lv, Changchun; Wang, Yang; Peng, Zhijian; Fu, Xiuli

Oxygen-deficient tin oxide thin films were prepared by radiofrequency magnetron sputtering with a sintered non-stoichiometric tin oxide ceramic target under an atmosphere of various ratios of O2/Ar from pure Ar to 1:1. X-ray diffraction analysis showed that the thin films were polycrystalline with relatively strong (1 1 0), (1 0 1) and (2 1 1) diffraction peaks. Scanning electron microscopy observation revealed that the thin films prepared at different O2/Ar ratios were all of relatively dense and homogeneous structure. With increasing O2/Ar ratio, the grain size of the films decreased slightly, and their chemical composition became close to the stoichiometric SnO2; but the deposition rate as well as film thickness increased first and then decreased sharply. It was revealed that the main defect in obtained films was oxygen vacancy (VO), and as the O2/Ar ratio increased, the concentration of VO fell down monotonously, which would lead to an increased electrical resistivity.

Pulse I-V characterization of a nano-crystalline oxide device with sub-gap density of states

NASA Astrophysics Data System (ADS)

Kim, Taeho; Hur, Ji-Hyun; Jeon, Sanghun

2016-05-01

Understanding the charge trapping nature of nano-crystalline oxide semiconductor thin film transistors (TFTs) is one of the most important requirements for their successful application. In our investigation, we employed a fast-pulsed I-V technique for understanding the charge trapping phenomenon and for characterizing the intrinsic device performance of an amorphous/nano-crystalline indium-hafnium-zinc-oxide semiconductor TFT with varying density of states in the bulk. Because of the negligible transient charging effect with a very short pulse, the source-to-drain current obtained with the fast-pulsed I-V measurement was higher than that measured by the direct-current characterization method. This is because the fast-pulsed I-V technique provides a charge-trap free environment, suggesting that it is a representative device characterization methodology of TFTs. In addition, a pulsed source-to-drain current versus time plot was used to quantify the dynamic trapping behavior. We found that the charge trapping phenomenon in amorphous/nano-crystalline indium-hafnium-zinc-oxide TFTs is attributable to the charging/discharging of sub-gap density of states in the bulk and is dictated by multiple trap-to-trap processes.

Pulse I-V characterization of a nano-crystalline oxide device with sub-gap density of states.

PubMed

Kim, Taeho; Hur, Ji-Hyun; Jeon, Sanghun

2016-05-27

Understanding the charge trapping nature of nano-crystalline oxide semiconductor thin film transistors (TFTs) is one of the most important requirements for their successful application. In our investigation, we employed a fast-pulsed I-V technique for understanding the charge trapping phenomenon and for characterizing the intrinsic device performance of an amorphous/nano-crystalline indium-hafnium-zinc-oxide semiconductor TFT with varying density of states in the bulk. Because of the negligible transient charging effect with a very short pulse, the source-to-drain current obtained with the fast-pulsed I-V measurement was higher than that measured by the direct-current characterization method. This is because the fast-pulsed I-V technique provides a charge-trap free environment, suggesting that it is a representative device characterization methodology of TFTs. In addition, a pulsed source-to-drain current versus time plot was used to quantify the dynamic trapping behavior. We found that the charge trapping phenomenon in amorphous/nano-crystalline indium-hafnium-zinc-oxide TFTs is attributable to the charging/discharging of sub-gap density of states in the bulk and is dictated by multiple trap-to-trap processes.

Microscopically crumpled indium-tin-oxide thin films as compliant electrodes with tunable transmittance

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

Ong, Hui-Yng; School of Engineering, Nanyang Polytechnic, Singapore 569830; Shrestha, Milan

2015-09-28

Indium-tin-oxide (ITO) thin films are perceived to be stiff and brittle. This letter reports that crumpled ITO thin films on adhesive poly-acrylate dielectric elastomer can make compliant electrodes, sustaining compression of up to 25% × 25% equi-biaxial strain and unfolding. Its optical transmittance reduces with crumpling, but restored with unfolding. A dielectric elastomer actuator (DEA) using the 14.2% × 14.2% initially crumpled ITO thin-film electrodes is electrically activated to produce a 37% areal strain. Such electric unfolding turns the translucent DEA to be transparent, with transmittance increased from 39.14% to 52.08%. This transmittance tunability promises to make a low-cost smart privacy window.

Electrical transport properties in indium tin oxide films prepared by electron-beam evaporation

NASA Astrophysics Data System (ADS)

Liu, X. D.; Jiang, E. Y.; Zhang, D. X.

2008-10-01

Amorphous and polycrystalline indium tin oxide films have been prepared by electron-beam evaporation method. The amorphous films exhibit semiconductor behavior, while metallic conductivity is observed in the polycrystalline samples. The magnetoconductivities of the polycrystalline films are positive at low temperatures and can be well described by the theory of three-dimensional weak-localization effect. In addition, the electron phase-breaking rate is proportional to T3/2. Comparing the experimental results with theory, we find that the electron-electron scattering is the dominant destroyer of the constructive interference in the films. In addition, the Coulomb interaction is the main contribution to the nontrivial corrections for the electrical conductivity at low temperatures.

Sputtering yields and surface chemical modification of tin-doped indium oxide in hydrocarbon-based plasma etching

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

Li, Hu; Karahashi, Kazuhiro; Hamaguchi, Satoshi, E-mail: hamaguch@ppl.eng.osaka-u.ac.jp

2015-11-15

Sputtering yields and surface chemical compositions of tin-doped indium oxide (or indium tin oxide, ITO) by CH{sup +}, CH{sub 3}{sup +}, and inert-gas ion (He{sup +}, Ne{sup +}, and Ar{sup +}) incidence have been obtained experimentally with the use of a mass-selected ion beam system and in-situ x-ray photoelectron spectroscopy. It has been found that etching of ITO is chemically enhanced by energetic incidence of hydrocarbon (CH{sub x}{sup +}) ions. At high incident energy incidence, it appears that carbon of incident ions predominantly reduce indium (In) of ITO and the ITO sputtering yields by CH{sup +} and CH{sub 3}{sup +}more » ions are found to be essentially equal. At lower incident energy (less than 500 eV or so), however, a hydrogen effect on ITO reduction is more pronounced and the ITO surface is more reduced by CH{sub 3}{sup +} ions than CH{sup +} ions. Although the surface is covered more with metallic In by low-energy incident CH{sub 3}{sup +} ions than CH{sup +} ions and metallic In is in general less resistant against physical sputtering than its oxide, the ITO sputtering yield by incident CH{sub 3}{sup +} ions is found to be lower than that by incident CH{sup +} ions in this energy range. A postulation to account for the relation between the observed sputtering yield and reduction of the ITO surface is also presented. The results presented here offer a better understanding of elementary surface reactions observed in reactive ion etching processes of ITO by hydrocarbon plasmas.« less

Induced nano-scale self-formed metal-oxide interlayer in amorphous silicon tin oxide thin film transistors.

PubMed

Liu, Xianzhe; Xu, Hua; Ning, Honglong; Lu, Kuankuan; Zhang, Hongke; Zhang, Xiaochen; Yao, Rihui; Fang, Zhiqiang; Lu, Xubing; Peng, Junbiao

2018-03-07

Amorphous Silicon-Tin-Oxide thin film transistors (a-STO TFTs) with Mo source/drain electrodes were fabricated. The introduction of a ~8 nm MoO x interlayer between Mo electrodes and a-STO improved the electron injection in a-STO TFT. Mo adjacent to the a-STO semiconductor mainly gets oxygen atoms from the oxygen-rich surface of a-STO film to form MoO x interlayer. The self-formed MoO x interlayer acting as an efficient interface modification layer could conduce to the stepwise internal transport barrier formation while blocking Mo atoms diffuse into a-STO layer, which would contribute to the formation of ohmic contact between Mo and a-STO film. It can effectively improve device performance, reduce cost and save energy for the realization of large-area display with high resolution in future.

High-performance a-IGZO thin-film transistor with conductive indium-tin-oxide buried layer

NASA Astrophysics Data System (ADS)

Ahn, Min-Ju; Cho, Won-Ju

2017-10-01

In this study, we fabricated top-contact top-gate (TCTG) structure of amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs) with a thin buried conductive indium-tin oxide (ITO) layer. The electrical performance of a-IGZO TFTs was improved by inserting an ITO buried layer under the IGZO channel. Also, the effect of the buried layer's length on the electrical characteristics of a-IGZO TFTs was investigated. The electrical performance of the transistors improved with increasing the buried layer's length: a large on/off current ratio of 1.1×107, a high field-effect mobility of 35.6 cm2/Vs, a small subthreshold slope of 116.1 mV/dec, and a low interface trap density of 4.2×1011 cm-2eV-1 were obtained. The buried layer a-IGZO TFTs exhibited enhanced transistor performance and excellent stability against the gate bias stress.

A charge optimized many-body potential for titanium nitride (TiN).

PubMed

Cheng, Y-T; Liang, T; Martinez, J A; Phillpot, S R; Sinnott, S B

2014-07-02

This work presents a new empirical, variable charge potential for TiN systems in the charge-optimized many-body potential framework. The potential parameters were determined by fitting them to experimental data for the enthalpy of formation, lattice parameters, and elastic constants of rocksalt structured TiN. The potential does a good job of describing the fundamental physical properties (defect formation and surface energies) of TiN relative to the predictions of first-principles calculations. This potential is used in classical molecular dynamics simulations to examine the interface of fcc-Ti(0 0 1)/TiN(0 0 1) and to characterize the adsorption of oxygen atoms and molecules on the TiN(0 0 1) surface. The results indicate that the potential is well suited to model TiN thin films and to explore the chemistry associated with their oxidation.

Organic derivatives of tin (II/IV): Investigation of their structure

NASA Astrophysics Data System (ADS)

Szirtes, L.; Megyeri, J.; Kuzmann, E.; Beck, A.

2011-07-01

The structures of tin(II)-oxalate, tin(IV)Na-EDTA and tin(IV)Na 8-inositol hexaphosphate were investigated using XRD analysis. Samples were identified using the Mössbauer study, thermal analysis and FTIR spectrometry. The Mössbauer study determined two different oxidation states of tin atoms, and consequently two different tin surroundings in the end products. The tin oxalate was found to be orthorhombic with space group Pnma, a=9.2066(3) Å, b=9.7590(1) Å, c=13.1848(5) Å, V=1184.62 Å 3 and Z=8. SnNa-EDTA was found to be monoclinic with space group P2 1/c 1, a=10.7544(3) Å, b=10.1455(3) Å, c=16.5130(6) Å, β=98.59(2)°, V=1781.50(4) Å 3 and Z=4. Sn(C 6H 6Na 8O 24P 6) was found to be amorphous.

Effect of wastewater quality parameters on coliform inactivation by tin oxide anodes.

PubMed

Teel, Amy L; Watts, Richard J

2018-04-16

The effect of six water quality constituents on wastewater effluent disinfection by tin oxide anodes (TOAs) was investigated in single cell laboratory reactors. Several concentrations of suspended solids, chemical oxygen demand (COD), alkalinity, ammonia-nitrogen, nitrite-nitrogen, and nitrate-nitrogen were added to media containing 10 6 total coliform bacteria mL -1 . Current was applied through the TOAs, and coliform bacteria viability was analyzed over time. Over 99.9% inactivation of coliform bacteria was found over 15 min in TOA reactors. Concentrations of the six water quality constituents typical of concentrations found in wastewaters had no effect on TOA disinfection efficacy. The results of this research demonstrate that TOAs, which could potentially be powered by solar panels, have potential as a sustainable disinfection process compared to chlorine, ozone, and ultraviolet light.

Reductive spectrophotometry of divalent tin sensitization on soda lime glass

NASA Astrophysics Data System (ADS)

Bejugam, Vinith; Wei, Xingfei; Roper, D. Keith

2016-07-01

Rapid and facile evaluation of tin (II) sensitization could lead to improved understanding of metal deposition in electroless (EL) plating. This report used a balanced redox reaction between 3,3‧,5,5‧-tetramethylbenzidine dihydrochloride (TMB-HCL) and N-bromosuccinimide (NBS) to evaluate effects of sensitization conditions (i.e., sensitization time, analyte concentration, aqueous immersion, and acid content) on the accumulated mass of surface-associated divalent tin ion. The accumulated mass of tin (II) increased as the sensitization time increased up to 30 s in proportion to aqueous tin (II) chloride concentrations between 2.6 and 26 mM at a trifluoroacetic acid (TFA) content of 68 mM. The average mass peaked at 7.3 nanomoles (nmol) per cm2 after a 5 s aqueous immersion post-sensitization, and then decreased with increasing aqueous immersion post-sensitization. The total average tin (II) + tin (IV) accumulated on soda lime glass measured by inductively coupled plasma optical emission spectrometry (ICP-OES) was 17% higher at 30 s sensitization, suggesting a fraction of the tin (II) present may have oxidized to tin (IV). These results indicated that in situ spectrophotometric evaluation of tin (II) could support development of EL plating for electronics, catalysis, and solar cells.

In situ loading of well-dispersed silver nanoparticles on nanocrystalline magnesium oxide for real-time monitoring of catalytic reactions by surface enhanced Raman spectroscopy.

PubMed

Zhang, Kaige; Li, Gongke; Hu, Yuling

2015-10-28

The surface-enhanced Raman spectroscopy (SERS) technique is of great importance for insight into the transient reaction intermediates and mechanistic pathways involved in heterogeneously catalyzed chemical reactions under actual reaction conditions, especially in water. Herein, we demonstrate a facile method for in situ synthesis of nanocrystalline magnesium oxide-Ag(0) (nano MgO-Ag(0)) hybrid nanomaterials with dispersed Ag nanoparticles (Ag NPs) on the surface of nanocrystalline magnesium oxide (nano MgO) via Sn(2+) linkage and reduction. As a benefit from the synergy effect of nano MgO and Ag NPs, the nano MgO-Ag(0) exhibited both excellent SERS and catalytic activities for the reduction of 4-nitrothiophenol in the presence of NaBH4. The nano MgO-Ag(0) was used for real-time monitoring of the catalytic reaction process of 4-nitrothiophenol to 4-aminothiophenol in an aqueous medium by observing the SERS signals of the reactant, intermediate and final products. The intrinsic reaction kinetics and reaction mechanism of this reaction were also investigated. This SERS-based synergy technique provides a novel approach for quantitative in situ monitoring of catalytic chemical reaction processes.

Electrocatalytic performance of Pt nanoparticles sputter-deposited on indium tin oxide toward methanol oxidation reaction: The particle size effect

NASA Astrophysics Data System (ADS)

Ting, Chao-Cheng; Chao, Chih-Hsuan; Tsai, Cheng Yu; Cheng, I.-Kai; Pan, Fu-Ming

2017-09-01

We sputter-deposited Pt nanoparticles with an average size ranging from 2.0 nm to 8.5 nm on the indium-tin oxide (ITO) glass substrate, and studied the effect of the size of Pt nanoparticles on electrocatalytic activity of the Pt/ITO electrode toward methanol oxidation reaction (MOR) in acidic solution. X-ray photoelectron spectroscopy (XPS) reveals an interfacial oxidized Pt layer present between Pt nanoparticles and the ITO substrate, which may modify the surface electronic structure of Pt nanoparticles and thus influences the electrocatalytic properties of the Pt catalyst toward MOR. According to electrochemical analyses, smaller Pt nanoparticles exhibit slower kinetics for CO electrooxidation and MOR. However, a smaller particle size enables better CO tolerance because the bifunctional mechanism is more effective on smaller Pt nanoparticles. The electrocatalytic activity decays rapidly for Pt nanoparticles with a size smaller than 3 nm and larger than 8 nm. The rapid activity decay is attributed to Pt dissolution for smaller nanoparticles and to CO poisoning for larger ones. Pt nanoparticles of 5-6 nm in size loaded on ITO demonstrate a greatly improved electrocatalytic activity and stability compared with those deposited on different substrates in our previous studies.

Electron beam induced damage in ITO coated Kapton. [Indium Tin Oxide

NASA Technical Reports Server (NTRS)

Krainsky, I.; Gordon, W. L.; Hoffman, R. W.

1981-01-01

Data for the stability of thin conductive indium tin oxide films on 0.003 inch thick Kapton substrates during exposure of the surface to electron beams are reported. The electron beam energy was 3 keV and the diameter was about 0.8 mm. Thermal effects and surface modifications are considered. For primary current greater than 0.6 microamperes, an obvious dark discoloration with diameter approximately that of the beam was produced. The structure of the discolored region was studied with the scanning electron microscope, and the findings are stated. Surface modifications were explored by AES, obtaining spectra and secondary emission coefficient as a function of time for different beam intensities. In all cases beam exposure results in a decrease of the secondary yield but because of thermal effects this change, as well as composition changes, cannot be directly interpreted in terms of electron beam dosage.

Fabricate heterojunction diode by using the modified spray pyrolysis method to deposit nickel-lithium oxide on indium tin oxide substrate.

PubMed

Wu, Chia-Ching; Yang, Cheng-Fu

2013-06-12

P-type lithium-doped nickel oxide (p-LNiO) thin films were deposited on an n-type indium tin oxide (ITO) glass substrate using the modified spray pyrolysis method (SPM), to fabricate a transparent p-n heterojunction diode. The structural, optical, and electrical properties of the p-LNiO and ITO thin films and the p-LNiO/n-ITO heterojunction diode were characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), UV-visible spectroscopy, Hall effect measurement, and current-voltage (I-V) measurements. The nonlinear and rectifying I-V properties confirmed that a heterojunction diode characteristic was successfully formed in the p-LNiO/n-ITO (p-n) structure. The I-V characteristic was dominated by space-charge-limited current (SCLC), and the Anderson model demonstrated that band alignment existed in the p-LNiO/n-ITO heterojunction diode.

Nanocrystalline films for gas-reactive applications

DOEpatents

Eastman, Jeffrey A.; Thompson, Loren J.

2004-02-17

A gas sensor for detection of oxidizing and reducing gases, including O.sub.2, CO.sub.2, CO, and H.sub.2, monitors the partial pressure of a gas to be detected by measuring the temperature rise of an oxide-thin-film-coated metallic line in response to an applied electrical current. For a fixed input power, the temperature rise of the metallic line is inversely proportional to the thermal conductivity of the oxide coating. The oxide coating contains multi-valent cation species that change their valence, and hence the oxygen stoichiometry of the coating, in response to changes in the partial pressure of the detected gas. Since the thermal conductivity of the coating is dependent on its oxygen stoichiometry, the temperature rise of the metallic line depends on the partial pressure of the detected gas. Nanocrystalline (<100 nm grain size) oxide coatings yield faster sensor response times than conventional larger-grained coatings due to faster oxygen diffusion along grain boundaries rather than through grain interiors.

Tin-Assisted Synthesis of ɛ -Ga2O3 by Molecular Beam Epitaxy

NASA Astrophysics Data System (ADS)

Kracht, M.; Karg, A.; Schörmann, J.; Weinhold, M.; Zink, D.; Michel, F.; Rohnke, M.; Schowalter, M.; Gerken, B.; Rosenauer, A.; Klar, P. J.; Janek, J.; Eickhoff, M.

2017-11-01

The synthesis of ɛ -Ga2O3 and β -Ga2O3 by plasma-assisted molecular beam epitaxy on (001 )Al2O3 substrates is studied. The growth window of β -Ga2O3 in the Ga-rich regime, usually limited by the formation of volatile gallium suboxide, is expanded due to the presence of tin during the growth process, which stabilizes the formation of gallium oxides. X-ray diffraction, transmission electron microscopy, time-of-flight secondary-ion mass spectrometry, Raman spectroscopy, and atomic force microscopy are used to analyze the influence of tin on the layer formation. We demonstrate that it allows the synthesis of phase-pure ɛ -Ga2O3 . A growth model based on the oxidation of gallium suboxide by reduction of an intermediate sacrificial tin oxide is suggested.

Color properties of transparent and heat-reflecting MgF2-coated indium-tin-oxide films.

PubMed

Hamberg, I; Granqvist, C G

1983-02-15

The visual appearance of antireflection-coated transparent and heat-reflecting indium-tin-oxide (ITO) films on glass was studied by a colorimetric analysis in which the chromaticity coordinates for transmitted and reflected daylight were evaluated for various film thicknesses. A color purity of <1% in normal transmission and <10% in normal reflection could be achieved with ITO thicknesses in the 220-260- or 335-365-nm ranges and MgF2 thicknesses in the 90-105-nm range. These design criteria yield very efficient window coatings with high visual transmittance, low thermal emittance, and little or no perceived color.

Disorder induced semiconductor to metal transition and modifications of grain boundaries in nanocrystalline zinc oxide thin film

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

Singh, Fouran; Kumar, Vinod; Chaudhary, Babloo

2012-10-01

This paper report on the disorder induced semiconductor to metal transition (SMT) and modifications of grain boundaries in nanocrystalline zinc oxide thin film. Disorder is induced using energetic ion irradiation. It eliminates the possibility of impurities induced transition. However, it is revealed that some critical concentration of defects is needed for inducing such kind of SMT at certain critical temperature. Above room temperature, the current-voltage characteristics in reverse bias attributes some interesting phenomenon, such as electric field induced charge transfer, charge trapping, and diffusion of defects. The transition is explained by the defects induced disorder and strain in ZnO crystallitesmore » created by high density of electronic excitations.« less

Influence of Preferred Orientation on the Electrical Conductivity of Fluorine-Doped Tin Oxide Films

PubMed Central

Wang, Jian Tao; Shi, Xiang Lei; Liu, Wei Wei; Zhong, Xin Hua; Wang, Jian Nong; Pyrah, Leo; Sanderson, Kevin D.; Ramsey, Philip M.; Hirata, Masahiro; Tsuri, Keiko

2014-01-01

Current development of high-performance transparent conductive oxide (TCO) films is limited with tradeoff between carrier mobility and concentration since none of them can be improved without sacrificing the other. In this study, we prepare fluorine doped tin oxide (FTO) films by chemical vapor deposition with inclusions of different additives and report that the mobility can be varied from 0.65 to 28.5 cm2 V−1 s−1 without reducing the achieved high carrier concentration of 4 × 1020 cm−3. Such an increase in mobility is shown to be clearly associated with the development of (200) preferred orientation (PO) but concurrent degradation of (110) PO in films. Thus, at a constant high carrier concentration, the electrical conductivity can be improved via carrier mobility simply by PO control. Such a one-step approach avoiding conventional post-deposition treatment is suggested for developing next-generation FTO as well as other TCO films with better than ever conductivities. PMID:24419455

Steady-state solution growth of microcrystalline silicon on nanocrystalline seed layers on glass

NASA Astrophysics Data System (ADS)

Bansen, R.; Ehlers, C.; Teubner, Th.; Boeck, T.

2016-09-01

The growth of polycrystalline silicon layers on glass from tin solutions at low temperatures is presented. This approach is based on the steady-state solution growth of Si crystallites on nanocrystalline seed layers, which are prepared in a preceding process step. Scanning electron microscopy and atomic force microscopy investigations reveal details about the seed layer surfaces, which consist of small hillocks, as well as about Sn inclusions and gaps along the glass substrate after solution growth. The successful growth of continuous microcrystalline Si layers with grain sizes up to several ten micrometers shows the feasibility of the process and makes it interesting for photovoltaics. Project supported by the German Research Foundation (DFG) (No. BO 1129/5-1).

GaN-based light-emitting diodes with graphene/indium tin oxide transparent layer.

PubMed

Lai, Wei-Chih; Lin, Chih-Nan; Lai, Yi-Chun; Yu, Peichen; Chi, Gou Chung; Chang, Shoou-Jinn

2014-03-10

We have demonstrated a gallium nitride (GaN)-based green light-emitting diode (LED) with graphene/indium tin oxide (ITO) transparent contact. The ohmic characteristic of the p-GaN and graphene/ITO contact could be preformed by annealing at 500 °C for 5 min. The specific contact resistance of p-GaN/graphene/ITO (3.72E-3 Ω·cm²) is one order less than that of p-GaN/ITO. In addition, the 20-mA forward voltage of LEDs with graphene/ITO transparent (3.05 V) is 0.09 V lower than that of ITO LEDs (3.14 V). Besides, We have got an output power enhancement of 11% on LEDs with graphene/ITO transparent contact.

Sintered indium-tin oxide particles induce pro-inflammatory responses in vitro, in part through inflammasome activation.

PubMed

Badding, Melissa A; Schwegler-Berry, Diane; Park, Ju-Hyeong; Fix, Natalie R; Cummings, Kristin J; Leonard, Stephen S

2015-01-01

Indium-tin oxide (ITO) is used to make transparent conductive coatings for touch-screen and liquid crystal display electronics. As the demand for consumer electronics continues to increase, so does the concern for occupational exposures to particles containing these potentially toxic metal oxides. Indium-containing particles have been shown to be cytotoxic in cultured cells and pro-inflammatory in pulmonary animal models. In humans, pulmonary alveolar proteinosis and fibrotic interstitial lung disease have been observed in ITO facility workers. However, which ITO production materials may be the most toxic to workers and how they initiate pulmonary inflammation remain poorly understood. Here we examined four different particle samples collected from an ITO production facility for their ability to induce pro-inflammatory responses in vitro. Tin oxide, sintered ITO (SITO), and ventilation dust particles activated nuclear factor kappa B (NFκB) within 3 h of treatment. However, only SITO induced robust cytokine production (IL-1β, IL-6, TNFα, and IL-8) within 24 h in both RAW 264.7 mouse macrophages and BEAS-2B human bronchial epithelial cells. Our lab and others have previously demonstrated SITO-induced cytotoxicity as well. These findings suggest that SITO particles activate the NLRP3 inflammasome, which has been implicated in several immune-mediated diseases via its ability to induce IL-1β release and cause subsequent cell death. Inflammasome activation by SITO was confirmed, but it required the presence of endotoxin. Further, a phagocytosis assay revealed that pre-uptake of SITO or ventilation dust impaired proper macrophage phagocytosis of E. coli. Our results suggest that adverse inflammatory responses to SITO particles by both macrophage and epithelial cells may initiate and propagate indium lung disease. These findings will provide a better understanding of the molecular mechanisms behind an emerging occupational health issue.

Using Indium Tin Oxide To Mitigate Dust on Viewing Ports

NASA Technical Reports Server (NTRS)

2008-01-01

NASA plans to use a number of onboard viewing ports to measure lunar regolith in situ and to monitor robotic and human activities on the lunar or Martian surface. Because of the size and abundance of dust particles on these bodies, the potential for dust to occlude viewing ports and windows is high enough to threaten system lifetime and reliability, especially when activities rely on relaying video to either a habitat module or controllers on Earth. This project uses a technology being developed by KSC's Electrostatics and Surface Physics Laboratory to remove dust from windowlike surfaces. The technology applies an alternating electric potential to interlaced electrodes. In this application, we use indium tin oxide (ITO) to create various electrode patterns in order to determine the most reliable pattern for dust removal. This technology has application to systems where optical clarity is important. Specifically, this project considers the in situ resource utilization (ISRU) application of a viewing port for Raman spectroscopy, where the electrode pattern on glass would be coated with a scratch-resistant sapphire film (Al2O3).

Self-catalyzed carbon plasma-assisted growth of tin-doped indium oxide nanostructures by the sputtering method

NASA Astrophysics Data System (ADS)

Setti, Grazielle O.; de Jesus, Dosil P.; Joanni, Ednan

2016-10-01

In this work a new strategy for growth of nanostructured indium tin oxide (ITO) by RF sputtering is presented. ITO is deposited in the presence of a carbon plasma which reacts with the free oxygen atoms during the deposition, forming species like CO x . These species are removed from the chamber by the pumping system, and one-dimensional ITO nanostructures are formed without the need for a seed layer. Different values of substrate temperature and power applied to the gun containing the carbon target were investigated, resulting in different nanostructure morphologies. The samples containing a higher density of nanowires were covered with gold and evaluated as surface-enhanced Raman scattering substrates for detection of dye solutions. The concept might be applied to other oxides, providing a simple method for unidimensional nanostructural synthesis.

Au-Doped Indium Tin Oxide Ohmic Contacts to p-Type GaN

NASA Astrophysics Data System (ADS)

Guo, H.; Andagana, H. B.; Cao, X. A.

2010-05-01

Indium tin oxide (ITO) thin films doped with Au, Ni, or Pt (3.5 at.% to 10.5 at.%) were deposited on p-GaN epilayers (Mg ~4 × 1019 cm-3) using direct-current (DC) sputter codeposition. It was found that undoped ITO con- tacts to p-GaN exhibited leaky Schottky behavior, whereas the incorporation of a small amount of Au (3.5 at.% to 10.5 at.%) significantly improved their ohmic characteristics. Compared with standard Ni/ITO contacts, the Au-doped ITO contacts had a similar specific contact resistance in the low 10-2 Ω cm-2 range, but were more stable above 600°C and more transparent at blue wavelengths. These results provide support for the use of Au-doped ITO ohmic contact to p-type GaN in high-brightness blue light-emitting diodes.

Rear-side picosecond laser ablation of indium tin oxide micro-grooves

NASA Astrophysics Data System (ADS)

Liu, Peng; Wang, Wenjun; Mei, Xuesong; Liu, Bin; Zhao, Wanqin

2015-06-01

A comparative study of the fabrication of micro-grooves in indium tin oxide films by picosecond laser ablation for application in thin film solar cells is presented, evaluating the variation of different process parameters. Compared with traditional front-side ablation, rear-side ablation results in thinner grooves with varying laser power at a certain scan speed. In particular, and in contrast to front-side ablation, the width of the micro-grooves remains unchanged when the scan speed was changed. Thus, the micro-groove quality can be optimized by adjusting the scan speed while the groove width would not be affected. Furthermore, high-quality micro-grooves with ripple free surfaces and steep sidewalls could only be achieved when applying rear-side ablation. Finally, the formation mechanism of micro-cracks on the groove rims during rear-side ablation is analyzed and the cracks can be almost entirely eliminated by an optimization of the scan speed.

Electroreduction of carbon monoxide to liquid fuel on oxide-derived nanocrystalline copper.

PubMed

Li, Christina W; Ciston, Jim; Kanan, Matthew W

2014-04-24

The electrochemical conversion of CO2 and H2O into liquid fuel is ideal for high-density renewable energy storage and could provide an incentive for CO2 capture. However, efficient electrocatalysts for reducing CO2 and its derivatives into a desirable fuel are not available at present. Although many catalysts can reduce CO2 to carbon monoxide (CO), liquid fuel synthesis requires that CO is reduced further, using H2O as a H(+) source. Copper (Cu) is the only known material with an appreciable CO electroreduction activity, but in bulk form its efficiency and selectivity for liquid fuel are far too low for practical use. In particular, H2O reduction to H2 outcompetes CO reduction on Cu electrodes unless extreme overpotentials are applied, at which point gaseous hydrocarbons are the major CO reduction products. Here we show that nanocrystalline Cu prepared from Cu2O ('oxide-derived Cu') produces multi-carbon oxygenates (ethanol, acetate and n-propanol) with up to 57% Faraday efficiency at modest potentials (-0.25 volts to -0.5 volts versus the reversible hydrogen electrode) in CO-saturated alkaline H2O. By comparison, when prepared by traditional vapour condensation, Cu nanoparticles with an average crystallite size similar to that of oxide-derived copper produce nearly exclusive H2 (96% Faraday efficiency) under identical conditions. Our results demonstrate the ability to change the intrinsic catalytic properties of Cu for this notoriously difficult reaction by growing interconnected nanocrystallites from the constrained environment of an oxide lattice. The selectivity for oxygenates, with ethanol as the major product, demonstrates the feasibility of a two-step conversion of CO2 to liquid fuel that could be powered by renewable electricity.

Effect of cadmium-selenide quantum dots on the conductivity and photoconductivity of nanocrystalline indium oxide

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

Il’in, A. S., E-mail: as.ilin@physics.msu.ru; Fantina, N. P.; Martyshov, M. N.

The effect of cadmium-selenide quantum dots addition on the electrical and photoelectric properties of nanocrystalline indium oxide with nanocrystal dimensions in the range from 7 to 40 nm is studied. By impedance spectroscopy, it is shown that the addition of quantum dots substantially influences the resistance of interfaces between In{sub 2}O{sub 3} crystals. A change in the character of the photoconductivity spectrum of In{sub 2}O{sub 3} upon the addition of CdSe quantum dots is detected, and it is established that this change depends on the In{sub 2}O{sub 3}-nanocrystal dimensions. An energy band diagram is proposed to explain the observed changemore » in the photoconductivity spectrum of In{sub 2}O{sub 3} upon the addition of CdSe quantum dots.« less

Bio-active synthesis of tin oxide nanoparticles using eggshell membrane for energy storage application

NASA Astrophysics Data System (ADS)

Celina Selvakumari, J.; Nishanthi, S. T.; Dhanalakshmi, J.; Ahila, M.; Pathinettam Padiyan, D.

2018-05-01

Nano-sized tin oxide (SnO2) particles were synthesized using eggshell membrane (ESM), a natural bio-waste from the chicken eggshell. The crystallization of SnO2 into the tetragonal structure was confirmed from powder X-ray diffraction and the crystallite size ranged from 13 to 40 nm. Various shapes including rod, hexagonal and spherical SnO2 nanoparticles were observed from the morphological studies. The electrochemical impedance study revealed a lower charge transfer resistance (Rct) of 8.565 Ω and the presence of a constant phase element which arised due to surface roughness and porosity. Capacitive behavior seen in the cyclic voltammetry curve of the prepared SnO2 nanoparticles, find future applications in supercapacitors.

Time and voltage dependences of nanoscale dielectric constant modulation on indium tin oxide films

NASA Astrophysics Data System (ADS)

Li, Liang; Hao, Haoyue; Zhao, Hua

2017-01-01

The modulation of indium tin oxide (ITO) films through surface charge accumulation plays an important role in many different applications. In order to elaborately study the modulation, we measured the dielectric constant of the modulated layer through examining the excitation of surface plasmon polaritons. Charges were pumped on the surfaces of ITO films through applying high voltage in appropriate directions. Experiments unveiled that the dielectric constant of the modulated layer had large variation along with the nanoscale charge accumulation. Corresponding numerical results were worked out through combining Drude model and Mayadas-Shatzkes model. Based on the above results, we deduced the time and voltage dependences of accumulated charge density, which revealed a long-time charge accumulation process.

Tin recovery from tin slag using electrolysis method

NASA Astrophysics Data System (ADS)

Jumari, Arif; Purwanto, Agus; Nur, Adrian; Budiman, Annata Wahyu; Lerian, Metty; Paramita, Fransisca A.

2018-02-01

The process in industry, including in mining industry, would surely give negative effect such as waste polluting to the environment. Some of waste could be potentially reutilized to be a commodity with the higher economic value. Tin slag is one of them. The aim of this research was to recover the tin contained in tin slag. Before coming to the electrolysis, tin slag must be treated by dissolution. The grinded tin slag was dissolved into HCl solution to form a slurry. During dissolution, the slurry was agitated and heated, and finally filtered. The filtrate obtained was then electrolyzed. During the process of electrolysis, solid material precipitated on the used cathode. The precipitated solid was then separated and dried. The solid was then analyzed using XRD, XRF and SEM. The XRD analysis showed that the longest time of dissolution and electrolysis the highest the purity obtained in the product. The SEM analysis showed that the longest time of electrolysis the smallest tin particle obtained. Optimum time achieved in this research was 2 hours for the recovering time and 3 hours for the electrolysis time, with 9% tin recovered.

A comparison of ZnO films deposited on indium tin oxide and soda lime glass under identical conditions

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

Deka, Angshuman; Nanda, Karuna Kar

2013-06-15

ZnO films have been grown via a vapour phase transport (VPT) on soda lime glass (SLG) and indium-tin oxide (ITO) coated glass. ZnO film on ITO had traces of Zn and C which gives them a dark appearance while that appears yellowish-white on SLG. X-ray photoelectron spectroscopy studies confirm the traces of C in the form of C-O. The photoluminescence studies reveal a prominent green luminescence band for ZnO film on ITO.

Direct Logistic Fuel JP-8 Conversion in a Liquid Tin Anode Solid Oxide Fuel Cell (LTA-SOFC)

DTIC Science & Technology

2008-04-09

GeSnOOSn sgl [1] As governed by the Nernst equation Open Circuit Voltage (OCV) is inversely proportional to temperature. The OCV of...inherently stable at 1,000°C. The LTA-SOFC electrochemical reaction is based on the following thermodynamic equation . C1000T kJ 311 42 o)(2... equation 1 is 0.8V at 1000°C, using an oxygen partial pressure of one. This equation gives the OCV for a LTA–SOFC functioning as a battery. The tin oxide

Synergistic Effect of Nitrogen and Refractory Material on TiN Formation and Equiaxed Grain Structure of Ferritic Stainless Steel

NASA Astrophysics Data System (ADS)

Lee, Mun Hyung; Park, Joo Hyun

2018-06-01

The effect of nitrogen content on the formation of an equiaxed solidification structure of Fe-16Cr steel was investigated. Moreover, two different kinds of refractory materials, i.e., alumina and magnesia, were employed to control the type of oxide inclusion. The characteristics of TiN(-oxide) inclusions were quantitatively analyzed in both molten steel and solidified samples. When the melting was carried out in the alumina refractory, the grain size continuously decreased with increasing nitrogen content. However, a minimum grain size was observed at a specific nitrogen content (approx. 150 ppm) when the steel was melted in the magnesia refractory. Most of the single TiN particles had a cuboidal shape and fine irregularly shaped particles were located along the grain boundary due to the microsegregation of Ti at the grain boundary during solidification. The type of TiN-oxide hybrid inclusion was strongly affected by the refractory material where Al2O3-TiN and MgAl2O4-TiN hybrid-type inclusions were obtained in the alumina and magnesia refractory experiments, respectively. The formation of oxide inclusions was well predicted by thermochemical computations and it was commonly found that oxide particles were initially formed, followed by the nucleation and growth of TiN. When the nitrogen content increased, the number density of TiN linearly increased in the alumina refractory experiments. However, the number of TiN exhibits a maximum at about [N] = 150 ppm, at which a minimum grain size was obtained in the magnesia refractory experiments. Therefore, the larger the number density of TiN, the smaller the primary grain size after solidification. The number density of TiN in the steel melted in the magnesia refractory was greater than that in the steel melted in the alumina refractory at given Ti and N contents, which was due to the lower planar lattice disregistry of MgAl2O4-TiN interface rather than that of Al2O3-TiN interface. When Δ T TiN (= difference between the

Synergistic Effect of Nitrogen and Refractory Material on TiN Formation and Equiaxed Grain Structure of Ferritic Stainless Steel

NASA Astrophysics Data System (ADS)

Lee, Mun Hyung; Park, Joo Hyun

2018-03-01

The effect of nitrogen content on the formation of an equiaxed solidification structure of Fe-16Cr steel was investigated. Moreover, two different kinds of refractory materials, i.e., alumina and magnesia, were employed to control the type of oxide inclusion. The characteristics of TiN(-oxide) inclusions were quantitatively analyzed in both molten steel and solidified samples. When the melting was carried out in the alumina refractory, the grain size continuously decreased with increasing nitrogen content. However, a minimum grain size was observed at a specific nitrogen content (approx. 150 ppm) when the steel was melted in the magnesia refractory. Most of the single TiN particles had a cuboidal shape and fine irregularly shaped particles were located along the grain boundary due to the microsegregation of Ti at the grain boundary during solidification. The type of TiN-oxide hybrid inclusion was strongly affected by the refractory material where Al2O3-TiN and MgAl2O4-TiN hybrid-type inclusions were obtained in the alumina and magnesia refractory experiments, respectively. The formation of oxide inclusions was well predicted by thermochemical computations and it was commonly found that oxide particles were initially formed, followed by the nucleation and growth of TiN. When the nitrogen content increased, the number density of TiN linearly increased in the alumina refractory experiments. However, the number of TiN exhibits a maximum at about [N] = 150 ppm, at which a minimum grain size was obtained in the magnesia refractory experiments. Therefore, the larger the number density of TiN, the smaller the primary grain size after solidification. The number density of TiN in the steel melted in the magnesia refractory was greater than that in the steel melted in the alumina refractory at given Ti and N contents, which was due to the lower planar lattice disregistry of MgAl2O4-TiN interface rather than that of Al2O3-TiN interface. When ΔT TiN (= difference between the

Metal-induced crystallization of amorphous zinc tin oxide semiconductors for high mobility thin-film transistors

NASA Astrophysics Data System (ADS)

Hwang, Ah Young; Kim, Sang Tae; Ji, Hyuk; Shin, Yeonwoo; Jeong, Jae Kyeong

2016-04-01

Transition tantalum induced crystallization of amorphous zinc tin oxide (a-ZTO) was observed at low temperature annealing of 300 °C. Thin-film transistors (TFTs) with an a-ZTO channel layer exhibited a reasonable field-effect mobility of 12.4 cm2/V s, subthreshold swing (SS) of 0.39 V/decade, threshold voltage (VTH) of 1.5 V, and ION/OFF ratio of ˜107. A significant improvement in the field-effect mobility (up to ˜33.5 cm2/V s) was achieved for crystallized ZTO TFTs: this improvement was accomplished without compromising the SS, VTH, or ION/OFF ratio due to the presence of a highly ordered microstructure.

The Effects of Oxidation Layer, Temperature, and Stress on Tin Whisker Growth: A Short Review

NASA Astrophysics Data System (ADS)

Mahim, Z.; Salleh, M. A. A.; Khor, C. Y.

2018-03-01

In order to reduce the Tin (Sn) whisker growth phenomenon in solder alloys, the researcher all the world has studied the factor of this behaviour. However, this phenomenon still hunted the electronic devices and industries. The whiskers growth were able to cause the electrical short, which would lead to the catastrophic such as plane crush, the failure of heart pacemaker, and the lost satellite connection. This article focuses on the three factors that influence the whiskers growth in solder alloys which is stress, oxidation layer and temperature. This findings were allowed the researchers to develop various method on how to reduce the growth of the Sn whiskers.

Superlative TINs

NASA Technical Reports Server (NTRS)

Chamberlin, R.

2002-01-01

TIN is short for 'triangulated irregular network,' which is a piecewise planar model of a surface. If properly constructed, a TIN can be more than 30 times as efficient as a regular triangulation. In our project (a ground combat simulation to support U.S. Army training exercises), the TIN is used to represent the Earth's surface and is used primarily to determine whether line of sight is blocked by terrain. High efficiency requires accurate identification of ridgelines with as few triangles as possible. The work currently in progress is the implementation of a TINning process that we hope will produce superlative TINs. This presentation describes that process.

Large optical nonlinearity of indium tin oxide in its epsilon-near-zero region.

PubMed

Alam, M Zahirul; De Leon, Israel; Boyd, Robert W

2016-05-13

Nonlinear optical phenomena are crucial for a broad range of applications, such as microscopy, all-optical data processing, and quantum information. However, materials usually exhibit a weak optical nonlinearity even under intense coherent illumination. We report that indium tin oxide can acquire an ultrafast and large intensity-dependent refractive index in the region of the spectrum where the real part of its permittivity vanishes. We observe a change in the real part of the refractive index of 0.72 ± 0.025, corresponding to 170% of the linear refractive index. This change in refractive index is reversible with a recovery time of about 360 femtoseconds. Our results offer the possibility of designing material structures with large ultrafast nonlinearity for applications in nanophotonics. Copyright © 2016, American Association for the Advancement of Science.

Effect of Target Density on Microstructural, Electrical, and Optical Properties of Indium Tin Oxide Thin Films

NASA Astrophysics Data System (ADS)

Zhu, Guisheng; Zhi, Li; Yang, Huijuan; Xu, Huarui; Yu, Aibing

2012-09-01

In this paper, indium tin oxide (ITO) targets with different densities were used to deposit ITO thin films. The thin films were deposited from these targets at room temperature and annealed at 750°C. Microstructural, electrical, and optical properties of the as-prepared films were studied. It was found that the target density had no effect on the properties or deposition rate of radiofrequency (RF)-sputtered ITO thin films, different from the findings for direct current (DC)-sputtered films. Therefore, when using RF sputtering, the target does not require a high density and may be reused.

Catalyst for Decomposition of Nitrogen Oxides

NASA Technical Reports Server (NTRS)

Schryer, David R. (Inventor); Akyurtlu, Ates (Inventor); Jordan, Jeffrey D. (Inventor); Akyurtlu, Jale (Inventor)

2015-01-01

This invention relates generally to a platinized tin oxide-based catalyst. It relates particularly to an improved platinized tin oxide-based catalyst able to decompose nitric oxide to nitrogen and oxygen without the necessity of a reducing gas.

Study of quartz crystal microbalance NO2 sensor coated with sputtered indium tin oxide film

NASA Astrophysics Data System (ADS)

Georgieva, V.; Aleksandrova, M.; Stefanov, P.; Grechnikov, A.; Gadjanova, V.; Dilova, T.; Angelov, Ts

2014-12-01

A study of NO2 gas sorption ability of thin indium tin oxide (ITO) deposited on 16 MHz quartz crystal microbalance (QCM) is presented. ITO films are grown by RF sputtering of indium/tin target with weight proportion 95:5 in oxygen environment. The ITO films have been characterized by X-ray photoelectron spectroscopy measurements. The ITO surface composition in atomic % is defined to be: In-40.6%, Sn-4.3% and O-55%. The thickness and refractive index of the films are determined by ellipsometric method. The frequency shift of QCM-ITO is measured at different NO2 concentrations. The QCM-ITO system becomes sensitive at NO2 concentration >= 500 ppm. The sorbed mass for each concentration is calculated according the Sauerbrey equation. The results indicated that the 1.09 ng of the gas is sorbed into 150 nm thick ITO film at 500 ppm NO2 concentration. When the NO2 concentration increases 10 times the calculated loaded mass is 5.46 ng. The sorption process of the gas molecules is defined as reversible. The velocity of sorbtion /desorption processes are studied, too. The QCM coated with thin ITO films can be successfully used as gas sensors for detecting NO2 in the air at room temperature.

Metallic tin quantum sheets confined in graphene toward high-efficiency carbon dioxide electroreduction

NASA Astrophysics Data System (ADS)

Lei, Fengcai; Liu, Wei; Sun, Yongfu; Xu, Jiaqi; Liu, Katong; Liang, Liang; Yao, Tao; Pan, Bicai; Wei, Shiqiang; Xie, Yi

2016-09-01

Ultrathin metal layers can be highly active carbon dioxide electroreduction catalysts, but may also be prone to oxidation. Here we construct a model of graphene confined ultrathin layers of highly reactive metals, taking the synthetic highly reactive tin quantum sheets confined in graphene as an example. The higher electrochemical active area ensures 9 times larger carbon dioxide adsorption capacity relative to bulk tin, while the highly-conductive graphene favours rate-determining electron transfer from carbon dioxide to its radical anion. The lowered tin-tin coordination numbers, revealed by X-ray absorption fine structure spectroscopy, enable tin quantum sheets confined in graphene to efficiently stabilize the carbon dioxide radical anion, verified by 0.13 volts lowered potential of hydroxyl ion adsorption compared with bulk tin. Hence, the tin quantum sheets confined in graphene show enhanced electrocatalytic activity and stability. This work may provide a promising lead for designing efficient and robust catalysts for electrolytic fuel synthesis.

Thin film deposition of conducting tin oxide from TMT in a low pressure glow discharge diode reactor

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

Farber, Y.; Arefi, F.; Amouroux, J.

1993-12-31

This work concerns the study of the deposition mechanisms of tin oxide and its characterization from a mixture of Ar + TMT + O{sub 2} in a RF glow discharge diode reactor at low pressure (0.1-0.3 mbar). The gaseous mixture is introduced in the center of the HV electrode and the glass substrates are placed on the grounded electrode. With the help of an optical fiber fixed in front of a quartz window the discharge was characterized in line. The deposited material is characterized by different surface diagnostic techniques such as XPS, FTIR, SEM/EDX. The sheet conductivity of the thinmore » films were measured by a 4 point-probe measurements. The first step of this work has been to optimize the working parameters (such as the gas composition, the interelectrode gap, the injected power and the treatment time) in order to obtain SnO{sub 2{minus}x}C{sub y} films with reproducible properties. While the second step was devoted to adjust the partial pressure of oxygen in TMT + O{sub 2} + Ar mixture in the aim to decrease the carbon content of the deposit. The carbon-free in oxide films obtained in this way (Sn/O{approx}0.5) present conductivities varying from 10{sup {minus}4} S.cm{sup {minus}1} up to 10{sup 2} S.cm{sup {minus}1} with thicknesses in the range of 500 to 20000 {angstrom}. The conductivity of the films can be improved by either an annealing process in nitrogen gas or by a hydrogen plasma post-treatment. Moreover, in the case of the latter, {beta}Sn crystalline phase has been identified. Finally, the transparent tin oxide films being prepared at relatively low temperature (=100{degrees}C) can be very well realized on polymeric substrates.« less

Functionalization of indium-tin-oxide electrodes by laser-nanostructured gold thin films for biosensing applications

NASA Astrophysics Data System (ADS)

Grochowska, Katarzyna; Siuzdak, Katarzyna; Karczewski, Jakub; Śliwiński, Gerard

2015-12-01

The production and properties of the indium-tin-oxide (ITO) electrodes functionalized by Au nanoparticle (NP) arrays of a relatively large area formed by pulsed laser nanostructuring of thin gold films are reported and discussed. The SEM inspection of modified electrodes reveals the presence of the nearly spherical and disc-shaped particles of dimensions in the range of 40-120 nm. The NP-array geometry can be controlled by selection of the laser processing conditions. It is shown that particle size and packing density of the array are important factors which determine the electrode performance. In the case of NP-modified electrodes the peak current corresponding to the glucose direct oxidation process shows rise with increasing glucose concentration markedly higher comparing to the reference Au disc electrode. The detection limit reaches 12 μM and linear response of the sensor is observed from 0.1 to 47 mM that covers the normal physiological range of the blood sugar detection.

Ultra-Low-Power Smart Electronic Nose System Based on Three-Dimensional Tin Oxide Nanotube Arrays.

PubMed

Chen, Jiaqi; Chen, Zhuo; Boussaid, Farid; Zhang, Daquan; Pan, Xiaofang; Zhao, Huijuan; Bermak, Amine; Tsui, Chi-Ying; Wang, Xinran; Fan, Zhiyong

2018-06-04

In this work, we present a high-performance smart electronic nose (E-nose) system consisting of a multiplexed tin oxide (SnO 2 ) nanotube sensor array, read-out circuit, wireless data transmission unit, mobile phone receiver, and data processing application (App). Using the designed nanotube sensor device structure in conjunction with multiple electrode materials, high-sensitivity gas detection and discrimination have been achieved at room temperature, enabling a 1000 times reduction of the sensor's power consumption as compared to a conventional device using thin film SnO 2 . The experimental results demonstrate that the developed E-nose can identify indoor target gases using a simple vector-matching gas recognition algorithm. In addition, the fabricated E-nose has achieved state-of-the-art sensitivity for H 2 and benzene detection at room temperature with metal oxide sensors. Such a smart E-nose system can address the imperative needs for distributed environmental monitoring in smart homes, smart buildings, and smart cities.

Molecular diversity of the ammonia-oxidizing bacteria community in disused tin-mining ponds located within Kampar, Perak, Malaysia.

PubMed

Sow, S L S; Khoo, G; Chong, L K; Smith, T J; Harrison, P L; Ong, H K A

2014-02-01

Disused tin-mining ponds make up a significant amount of water bodies in Malaysia particularly at the Kinta Valley in the state of Perak where tin-mining activities were the most extensive, and these abundantly available water sources are widely used in the field of aquaculture and agriculture. However, the natural ecology and physicochemical conditions of these ponds, many of which have been altered due to secondary post-mining activities, remains to be explored. As ammonia-oxidizing bacteria (AOB) are directly related to the nutrient cycles of aquatic environments and are useful bioindicators of environmental variations, the focus of this study was to identify AOBs associated with disused tin-mining ponds that have a history of different secondary activities in comparison to ponds which were left untouched and remained as part of the landscape. The 16S rDNA gene was used to detect AOBs in the sediment and water sampled from the three types of disused mining ponds, namely ponds without secondary activity, ponds that were used for lotus cultivation and post-aquaculture ponds. When the varying pond types were compared with the sequence and phylogenetic analysis of the AOB clone libraries, both Nitrosomonas and Nitrosospira-like AOB were detected though Nitrosospira spp. was seen to be the most ubiquitous AOB as it was present in all ponds types. However, AOBs were not detected in the sediments of idle ponds. Based on rarefaction analysis and diversity indices, the disused mining pond with lotus culture indicated the highest richness of AOBs. Canonical correspondence analysis indicated that among the physicochemical properties of the pond sites, TAN and nitrite were shown to be the main factors that influenced the community structure of AOBs in these disused tin-mining ponds.

Thermally Stable Nanocrystalline Steel

NASA Astrophysics Data System (ADS)

Hulme-Smith, Christopher Neil; Ooi, Shgh Woei; Bhadeshia, Harshad K. D. H.

2017-10-01

Two novel nanocrystalline steels were designed to withstand elevated temperatures without catastrophic microstructural changes. In the most successful alloy, a large quantity of nickel was added to stabilize austenite and allow a reduction in the carbon content. A 50 kg cast of the novel alloy was produced and used to verify the formation of nanocrystalline bainite. Synchrotron X-ray diffractometry using in situ heating showed that austenite was able to survive more than 1 hour at 773 K (500 °C) and subsequent cooling to ambient temperature. This is the first reported nanocrystalline steel with high-temperature capability.

Large-scale fabrication of single crystalline tin nanowire arrays.

PubMed

Luo, Bin; Yang, Dachi; Liang, Minghui; Zhi, Linjie

2010-09-01

Large-scale single crystalline tin nanowire arrays with preferred lattice orientation along the [100] direction were fabricated in porous anodic aluminium oxide (AAO) membranes by the electrodeposition method using copper nanorod as a second electrode.

Development of glucose biosensors based on plasma polymerization-assisted nanocomposites of polyaniline, tin oxide, and three-dimensional reduced graphene oxide

NASA Astrophysics Data System (ADS)

Wu, Shide; Su, Fangfang; Dong, Xiaodong; Ma, Chuang; Pang, Long; Peng, Donglai; Wang, Minghua; He, Linghao; Zhang, Zhihong

2017-04-01

A biosensor based on the plasma polyaniline (pPANI)-modified tin oxide and 3D reduced graphene oxide (SnO2@3D-rGO) nanocomposite was fabricated to detect glucose. The SnO2@3D-rGO nanocomposite was synthesized by simultaneously reducing 3D graphene oxide (3D-GO) and translating SnCl4 into SnO2, followed by pPANI modification. The content of amino groups in the SnO2@3D-rGO@pPANI nanocomposites depended on the plasma input powers used in plasma deposition. The SnO2@3D-rGO nanocomposite was important in the electrochemical biosensor to detect glucose. The fabricated biosensor exhibited a much higher sensitivity than that formed from individual components, namely, SnO2@3D-rGO and pPANI. This biosensor demonstrated a low detection limit of 0.047 ng mL-1 (0.26 nM) (S/N = 3) within the concentration range of 0.1 ng mL-1 to 5 μg mL-1. The selectivity, stability, and practicality of the SnO2@3D-rGO@pPANI-based biosensor were observed. In conclusion, the plasma surface-modified nanocomposite is a promising candidate as biosensor for glucose detection and biological diagnosis.

Tuning the properties of tin oxide thin films for device fabrications

NASA Astrophysics Data System (ADS)

Sudha, A.; Sharma, S. L.; Gupta, A. N.; Sharma, S. D.

2017-11-01

Tin oxide thin films were deposited on well cleaned glass substrates by thermal evaporation in vacuum and were annealed at 500 ∘C in the open atmosphere inside a furnace for 90 min for promoting the sensitivity of the films. The X-ray diffraction studies revealed that the as-deposited films were amorphous in nature and the annealed films showed appreciable crystalline behavior. The annealed thin films were then irradiated using 60Co gamma source. The radiation induced changes were then studied by X-ray diffraction, scanning electron microscopy, UV-vis spectroscopy and I- V characterization. The remarkable increase in the average grain size, the decrement in the energy band gap and resistivity due to the gamma irradiations up to a certain dose and the reversal of these properties at higher doses are the important observations. The large changes in the conductivity and energy band gap of the annealed thin films due to gamma irradiation make these films quite important device material for the fabrication of gamma sensors and dosimeters.

THz behavior of indium-tin-oxide films on p-Si substrates

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

Brown, E. R., E-mail: elliott.brown@wright.edu; Zhang, W-D., E-mail: wzzhang@fastmail.fm; Chen, H.

2015-08-31

This paper reports broadband THz free-space transmission measurements and modeling of indium-tin-oxide (ITO) thin films on p-doped Si substrates. Two such samples having ITO thickness of 50 and 100 nm, and DC sheet conductance 260 and 56 Ω/sq, respectively, were characterized between 0.2 and 1.2 THz using a frequency-domain spectrometer. The 50-nm-film sample displayed very flat transmittance over the 1-THz bandwidth, suggesting it is close to the critical THz sheet conductance that suppresses multi-pass interference in the substrate. An accurate transmission-line-based equivalent circuit is developed to explain the effect, and then used to show that the net reflectivity and absorptivity necessarilymore » oscillate with frequency. This has important implications for the use of thin-film metallic coupling layers on THz components and devices, such as detectors and sources. Consistent with previous reported results, the sheet conductance that best fits the THz transmittance data is roughly 50% higher than the DC values for both samples.« less

Dye-controlled interfacial electron transfer for high-current indium tin oxide photocathodes.

PubMed

Huang, Zhongjie; He, Mingfu; Yu, Mingzhe; Click, Kevin; Beauchamp, Damian; Wu, Yiying

2015-06-01

Efficient sensitized photocathodes are highly desired for solar fuels and tandem solar cells, yet the development is hindered by the scarcity of suitable p-type semiconductors. The generation of high cathodic photocurrents by sensitizing a degenerate n-type semiconductor (tin-doped indium oxide; ITO) is reported. The sensitized mesoporous ITO electrodes deliver cathodic photocurrents of up to 5.96±0.19 mA cm(-2), which are close to the highest record in conventional p-type sensitized photocathodes. This is realized by the rational selection of dyes with appropriate energy alignments with ITO. The energy level alignment between the highest occupied molecular orbital of the sensitizer and the conduction band of ITO is crucial for efficient hole injection. Transient absorption spectroscopy studies demonstrate that the cathodic photocurrent results from reduction of the photoexcited sensitizer by free electrons in ITO. Our results reveal a new perspective toward the selection of electrode materials for sensitized photocathodes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Influences of Indium Tin Oxide Layer on the Properties of RF Magnetron-Sputtered (BaSr)TiO3 Thin Films on Indium Tin Oxide-Coated Glass Substrate

NASA Astrophysics Data System (ADS)

Kim, Tae Song; Oh, Myung Hwan; Kim, Chong Hee

1993-06-01

Nearly stoichiometric ((Ba+Sr)/Ti=1.08-1.09) and optically transparent (BaSr)TiO3 thin films were deposited on an indium tin oxide (ITO)-coated glass substrate by means of rf magnetron sputtering for their application to the insulating layer of an electroluminescent flat panel display. The influence of the ITO layer on the properties of (BaSr)TiO3 thin films deposited on the ITO-coated substrate was investigated. The ITO layer did not affect the crystallographic orientation of (BaSr)TiO3 thin film, but enhanced the grain growth. Another effect of the ITO layer on (BaSr)TiO3 thin films was the interdiffusion phenomenon, which was studied by means of secondary ion mass spectrometry (SIMS). As the substrate temperature increased, interdiffusion intensified at the interface not only between the grown film and ITO layer but also between the ITO layer and base glass substrate. The refractive index (nf) of (BaSr)TiO3 thin film deposited on a bare glass substrate was 2.138-2.286, as a function of substrate temperature.

Fabrication of Co3O4 mesoporous thin films by using cobalt/chitosan precursor on fluorine-doped tin oxide glass

NASA Astrophysics Data System (ADS)

Yang, Hui-Chia; Tsai, Jung-Che

2017-06-01

For the development of high-performance and low-cost electrode materials, many alternative materials have been fabricated by various groups. Among these materials, Co3O4 has been demonstrated to be a promising candidate for pseudocapacitors because of its low potential environmental pollution, low cost, and extremely high theoretical specific capacitance. Chitosan, a linear polysaccharide produced by the deacetylation of chitin, is a nontoxic, tissue-compatible polymeric biomaterial. It is usually used to eliminate or filter the heavy metals in wastewater. That is, chitosan can act as a deliverer of metal ions and a nanostructure constructer of metals (or metal oxides). In this study, a facile approach is developed to synthesize mesoporous cobalt oxide thin films on fluorine-doped tin oxide (FTO)-coated glass with environmentally friendly chitosan, which chelates cobalt ions.

Characteristics of indium-tin-oxide (ITO) nanoparticle ink-coated layers recycled from ITO scraps

NASA Astrophysics Data System (ADS)

Cha, Seung-Jae; Hong, Sung-Jei; Lee, Jae Yong

2015-09-01

This study investigates the characteristics of an indium-tin-oxide (ITO) ink layer that includes nanoparticles synthesized from ITO target scraps. The particle size of the ITO nanoparticle was less than 15 nm, and the crystal structure was cubic with a (222) preferred orientation. Also, the composition ratio of In to Sn was 92.7 to 7.3 in weight. The ITO nanoparticles were well dispersed in the ink solvent to formulate a 20-wt% ITO nanoparticle ink. Furthermore, the ITO nanoparticle ink was coated onto a glass substrate, followed by heat-treatment at 600 °C. The layer showed good sheet resistances below 400 Ω/□ and optical transmittances higher than 88% at 550 nm. Thus, we can conclude that the characteristics of the layer make it highly applicable to a transparent conductive electrode.

Silicon heterojunction solar cells with novel fluorinated n-type nanocrystalline silicon oxide emitters on p-type crystalline silicon

NASA Astrophysics Data System (ADS)

Dhar, Sukanta; Mandal, Sourav; Das, Gourab; Mukhopadhyay, Sumita; Pratim Ray, Partha; Banerjee, Chandan; Barua, Asok Kumar

2015-08-01

A novel fluorinated phosphorus doped silicon oxide based nanocrystalline material have been used to prepare heterojunction solar cells on flat p-type crystalline silicon (c-Si) Czochralski (CZ) wafers. The n-type nc-SiO:F:H material were deposited by radio frequency plasma enhanced chemical vapor deposition. Deposited films were characterized in detail by using atomic force microscopy (AFM), high resolution transmission electron microscopy (HRTEM), Raman, fourier transform infrared spectroscopy (FTIR) and optoelectronics properties have been studied using temperature dependent conductivity measurement, Ellipsometry, UV-vis spectrum analysis etc. It is observed that the cell fabricated with fluorinated silicon oxide emitter showing higher initial efficiency (η = 15.64%, Jsc = 32.10 mA/cm2, Voc = 0.630 V, FF = 0.77) for 1 cm2 cell area compare to conventional n-a-Si:H emitter (14.73%) on flat c-Si wafer. These results indicate that n type nc-SiO:F:H material is a promising candidate for heterojunction solar cell on p-type crystalline wafers. The high Jsc value is associated with excellent quantum efficiencies at short wavelengths (<500 nm).

In Situ Chemical Modification of Schottky Barrier in Solution-Processed Zinc Tin Oxide Diode.

PubMed

Son, Youngbae; Li, Jiabo; Peterson, Rebecca L

2016-09-14

Here we present a novel in situ chemical modification process to form vertical Schottky diodes using palladium (Pd) rectifying bottom contacts, amorphous zinc tin oxide (Zn-Sn-O) semiconductor made via acetate-based solution process, and molybdenum top ohmic contacts. Using X-ray photoelectron spectroscopy depth profiling, we show that oxygen plasma treatment of Pd creates a PdOx interface layer, which is then reduced back to metallic Pd by in situ reactions during Zn-Sn-O film annealing. The plasma treatment ensures an oxygen-rich environment in the semiconductor near the Schottky barrier, reducing the level of oxygen-deficiency-related defects and improving the rectifying contact. Using this process, we achieve diodes with high forward current density exceeding 10(3)A cm(-2) at 1 V, rectification ratios of >10(2), and ideality factors of around 1.9. The measured diode current-voltage characteristics are compared to numerical simulations of thermionic field emission with sub-bandgap states in the semiconductor, which we attribute to spatial variations in metal stoichiometry of amorphous Zn-Sn-O. To the best of our knowledge, this is the first demonstration of vertical Schottky diodes using solution-processed amorphous metal oxide semiconductor. Furthermore, the in situ chemical modification method developed here can be adapted to tune interface properties in many other oxide devices.

Electrical and Optical Characterization of Sputtered Silicon Dioxide, Indium Tin Oxide, and Silicon Dioxide/Indium Tin Oxide Antireflection Coating on Single-Junction GaAs Solar Cells

PubMed Central

Ho, Wen-Jeng; Lin, Jian-Cheng; Liu, Jheng-Jie; Bai, Wen-Bin; Shiao, Hung-Pin

2017-01-01

This study characterized the electrical and optical properties of single-junction GaAs solar cells coated with antireflective layers of silicon dioxide (SiO2), indium tin oxide (ITO), and a hybrid layer of SiO2/ITO applied using Radio frequency (RF) sputtering. The conductivity and transparency of the ITO film were characterized prior to application on GaAs cells. Reverse saturation-current and ideality factor were used to evaluate the passivation performance of the various coatings on GaAs solar cells. Optical reflectance and external quantum efficiency response were used to evaluate the antireflective performance of the coatings. Photovoltaic current-voltage measurements were used to confirm the efficiency enhancement obtained by the presence of the anti-reflective coatings. The conversion efficiency of the GaAs cells with an ITO antireflective coating (23.52%) exceeded that of cells with a SiO2 antireflective coating (21.92%). Due to lower series resistance and higher short-circuit current-density, the carrier collection of the GaAs cell with ITO coating exceeded that of the cell with a SiO2/ITO coating. PMID:28773063

A mixed solution-processed gate dielectric for zinc-tin oxide thin-film transistor and its MIS capacitance

NASA Astrophysics Data System (ADS)

Kim, Hunho; Kwack, Young-Jin; Yun, Eui-Jung; Choi, Woon-Seop

2016-09-01

Solution-processed gate dielectrics were fabricated with the combined ZrO2 and Al2O3 (ZAO) in the form of mixed and stacked types for oxide thin film transistors (TFTs). ZAO thin films prepared with double coatings for solid gate dielectrics were characterized by analytical tools. For the first time, the capacitance of the oxide semiconductor was extracted from the capacitance-voltage properties of the zinc-tin oxide (ZTO) TFTs with the combined ZAO dielectrics by using the proposed metal-insulator-semiconductor (MIS) structure model. The capacitance evolution of the semiconductor from the TFT model structure described well the threshold voltage shift observed in the ZTO TFT with the ZAO (1:2) gate dielectric. The electrical properties of the ZTO TFT with a ZAO (1:2) gate dielectric showed low voltage driving with a field effect mobility of 37.01 cm2/Vs, a threshold voltage of 2.00 V, an on-to-off current ratio of 1.46 × 105, and a subthreshold slope of 0.10 V/dec.

A mixed solution-processed gate dielectric for zinc-tin oxide thin-film transistor and its MIS capacitance

PubMed Central

Kim, Hunho; Kwack, Young-Jin; Yun, Eui-Jung; Choi, Woon-Seop

2016-01-01

Solution-processed gate dielectrics were fabricated with the combined ZrO2 and Al2O3 (ZAO) in the form of mixed and stacked types for oxide thin film transistors (TFTs). ZAO thin films prepared with double coatings for solid gate dielectrics were characterized by analytical tools. For the first time, the capacitance of the oxide semiconductor was extracted from the capacitance-voltage properties of the zinc-tin oxide (ZTO) TFTs with the combined ZAO dielectrics by using the proposed metal-insulator-semiconductor (MIS) structure model. The capacitance evolution of the semiconductor from the TFT model structure described well the threshold voltage shift observed in the ZTO TFT with the ZAO (1:2) gate dielectric. The electrical properties of the ZTO TFT with a ZAO (1:2) gate dielectric showed low voltage driving with a field effect mobility of 37.01 cm2/Vs, a threshold voltage of 2.00 V, an on-to-off current ratio of 1.46 × 105, and a subthreshold slope of 0.10 V/dec. PMID:27641430

Ab Initio Study of the Atomic Level Structure of the Rutile TiO2(110)-Titanium Nitride (TiN) Interface.

PubMed

Gutiérrez Moreno, José Julio; Nolan, Michael

2017-11-01

Titanium nitride (TiN) is widely used in industry as a protective coating due to its hardness and resistance to corrosion and can spontaneously form a thin oxide layer when it is exposed to air, which could modify the properties of the coating. With limited understanding of the TiO 2 -TiN interfacial system at present, this work aims to describe the structural and electronic properties of oxidized TiN based on a density functional theory (DFT) study of the rutile TiO 2 (110)-TiN(100) interface model system, also including Hubbard +U correction on Ti 3d states. The small lattice mismatch gives a good stability to the TiO 2 -TiN interface after depositing the oxide onto TiN through the formation of interfacial Ti-O bonds. Our DFT+U study shows the presence of Ti 3+ cations in the TiO 2 region, which are preferentially located next to the interface region as well as the rotation of the rutile TiO 2 octahedra in the interface structure. The DFT+U TiO 2 electronic density of states (EDOS) shows localized Ti 3+ defect states forming in the midgap between the top edge of the valence and the bottom of the conduction band. We increase the complexity of our models by the introduction of nonstoichiometric compositions. Although the vacancy formation energies for Ti in TiN (E vac (Ti) ≥ 4.03 eV) or O in the oxide (E vac (O) ≥ 3.40 eV) are quite high relative to perfect TiO 2 -TiN, defects are known to form during the oxide growth and can therefore be present after TiO 2 formation. Our results show that a structure with exchanged O and N can lie 0.82 eV higher in energy than the perfect system, suggesting the stability of structures with interdiffused O and N anions at ambient conditions. The presence of N in TiO 2 introduces N 2p states localized between the top edge of the O 2p valence states and the midgap Ti 3+ 3d states, thus reducing the band gap in the TiO 2 region for the exchanged O/N interface EDOS. The outcomes of these simulations give us a most comprehensive

XPS investigations of tribolayers formed on TiN and (Ti,Re)N coatings

NASA Astrophysics Data System (ADS)

Oktay, Serkan; Kahraman, Zafer; Urgen, Mustafa; Kazmanli, Kursat

2015-02-01

TiN and (Ti,Re)N coatings were deposited on high-speed-steel substrates by a hybrid coating system composed of cathodic arc PVD and magnetron sputtering techniques. In order to keep rhenium content low (8 ± 1.9 at.%) in the coating, magnetron sputtering technique was utilized to evaporate rhenium. The (Ti,Re)N coating consisted of TiN and ReNx (x > 1.33) phases. The hardness of TiN and (Ti,Re)N were 31 GPa and 29 GPa (± 2 GPa), respectively. Tribological behaviors of the samples were tested against Al2O3 balls at 21 °C (RT) and 150 °C (HT) by reciprocating wear technique. The tribolayers were analyzed by XPS technique. Friction coefficients of TiN were 0.56, 0.35 for 21 °C and 150 °C tests, respectively. Rhenium addition to TiN drastically dropped the friction coefficients to 0.22 and 0.17 for RT and HT samples. Rhenium addition also improved the wear resistance of the coating at both test temperatures. For TiN, main oxide component of the tribolayers was Ti2O3 for RT tests and TiO2 for HT tests. The oxide layer formed on (Ti,Re)N were the mixture of TiO2, Tisbnd Osbnd N, ReO2 and Re2O7 for both test temperatures. Re2O7 provided very low friction coefficient to (Ti,Re)N. The findings are consistent with the crystal chemistry approach.

Infrared photocurrent management in monolithic perovskite/silicon heterojunction tandem solar cells by using a nanocrystalline silicon oxide interlayer.

PubMed

Mazzarella, Luana; Werth, Matteo; Jäger, Klaus; Jošt, Marko; Korte, Lars; Albrecht, Steve; Schlatmann, Rutger; Stannowski, Bernd

2018-05-14

We performed optical simulations using hydrogenated nanocrystalline silicon oxide (nc-SiO x :H) as n-doped interlayer in monolithic perovskite/c-Si heterojunction tandem solar cells. Depending on the adjustable value of its refractive index (2.0 - 2.7) and thickness, nc-SiO x :H allows to optically manage the infrared light absorption in the c-Si bottom cell minimizing reflection losses. We give guidelines for nc-SiO x :H optimization in tandem devices in combination with a systematic investigation of the effect of the surface morphology (flat or textured) on the photocurrent density. For full-flat and rear textured devices, we found matched photocurrents higher than 19 and 20 mA/cm 2 , respectively, using a 90 nm nc-SiO x :H interlayer with a refractive index of 2.7.

Indium Tin Oxide-Magnesium Fluoride Co-Deposited Films for Spacecraft Applications

NASA Technical Reports Server (NTRS)

Dever, Joycer A.; Rutledge, Sharon K.; Hambourger, Paul D.; Bruckner, Eric; Ferrante, Rhea; Pal, Anna Marie; Mayer, Karen; Pietromica, Anthony J.

1998-01-01

Highly transparent coatings with a maximum sheet resistivity between 10(exp 8) and 10(exp 9) ohms/square are desired to prevent charging of solar arrays for low Earth polar orbit and geosynchronous orbit missions. Indium tin oxide (ITO) and magnesium fluoride (MgF2) were ion beam sputter co-deposited onto fused silica substrates and were evaluated for transmittance, sheet resistivity and the effects of simulated space environments including atomic oxygen (AO) and vacuum ultraviolet (VUV) radiation. Optical properties and sheet resistivity as a function of MgF2 content in the films will be presented. Films containing 8.4 wt.% MgF2 were found to be highly transparent and provided sheet resistivity in the required range. These films maintained a high transmittance upon exposure to AO and to VUV radiation, although exposure to AO in the presence of charged species and intense electromagnetic radiation caused significant degradation in film transmittance. Sheet resistivity of the as-fabricated films increased with time in ambient conditions. Vacuum beat treatment following film deposition caused a reduction in sheet resistivity. However, following vacuum heat treatment, sheet resistivity values remained stable during storage in ambient conditions.

Positron beam study of indium tin oxide films on GaN

NASA Astrophysics Data System (ADS)

Cheung, C. K.; Wang, R. X.; Beling, C. D.; Djurisic, A. B.; Fung, S.

2007-02-01

Variable energy Doppler broadening spectroscopy has been used to study open-volume defects formed during the fabrication of indium tin oxide (ITO) thin films grown by electron-beam evaporation on n-GaN. The films were prepared at room temperature, 200 and 300 °C without oxygen and at 200 °C under different oxygen partial pressures. The results show that at elevated growth temperatures the ITO has fewer open volume sites and grows with a more crystalline structure. High temperature growth, however, is not sufficient in itself to remove open volume defects at the ITO/GaN interface. Growth under elevated temperature and under partial pressure of oxygen is found to further reduce the vacancy type defects associated with the ITO film, thus improving the quality of the film. Oxygen partial pressures of 6 × 10-3 mbar and above are found to remove open volume defects associated with the ITO/GaN interface. The study suggests that, irrespective of growth temperature and oxygen partial pressure, there is only one type of defect in the ITO responsible for trapping positrons, which we tentatively attribute to the oxygen vacancy.

Stability study of solution-processed zinc tin oxide thin-film transistors

NASA Astrophysics Data System (ADS)

Zhang, Xue; Ndabakuranye, Jean Pierre; Kim, Dong Wook; Choi, Jong Sun; Park, Jaehoon

2015-11-01

In this study, the environmental dependence of the electrical stability of solution-processed n-channel zinc tin oxide (ZTO) thin-film transistors (TFTs) is reported. Under a prolonged negative gate bias stress, a negative shift in threshold voltage occurs in atmospheric air, whereas a negligible positive shift in threshold voltage occurs under vacuum. In the positive bias-stress experiments, a positive shift in threshold voltage was invariably observed both in atmospheric air and under vacuum. In this study, the negative gate-bias-stress-induced instability in atmospheric air is explained through an internal potential in the ZTO semiconductor, which can be generated owing to the interplay between H2O molecules and majority carrier electrons at the surface of the ZTO film. The positive bias-stress-induced instability is ascribed to electron-trapping phenomenon in and around the TFT channel region, which can be further augmented in the presence of air O2 molecules. These results suggest that the interaction between majority carriers and air molecules will have crucial implications for a reliable operation of solution-processed ZTO TFTs. [Figure not available: see fulltext.

Optoelectronic and magnetic properties of Mn-doped indium tin oxide: A first-principles study

NASA Astrophysics Data System (ADS)

Nath Tripathi, Madhvendra; Saeed Bahramy, Mohammad; Shida, Kazuhito; Sahara, Ryoji; Mizuseki, Hiroshi; Kawazoe, Yoshiyuki

2012-10-01

The manganese doped indium tin oxide (ITO) has integrated magnetics, electronics, and optical properties for next generation multifunctional devices. Our first-principles density functional theory (DFT) calculations show that the manganese atom replaces b-site indium atom, located at the second coordination shell of the interstitial oxygen in ITO. It is also found that both anti-ferromagnetic and ferromagnetic behaviors are realizable. The calculated magnetic moment of 3.95μB/Mn as well as the high transmittance of ˜80% for a 150 nm thin film of Mn doped ITO is in good agreement with the experimental data. The inclusion of on-site Coulomb repulsion corrections via DFT + U methods turns out to improve the optical behavior of the system. The optical behaviors of this system reveal its suitability for the magneto-opto-electronic applications.

Raman Scattering from Tin

DTIC Science & Technology

2015-09-01

ARL-TR-7448 ● SEP 2015 US Army Research Laboratory Raman Scattering from Tin by Patrick A Folkes, Patrick Taylor, Charles Rong...REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE Raman Scattering from Tin 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c... tin as an analytical tool for discerning specific allotropic differences in ultra-thin tin films, and discerning differences between the tin and the

Highly flexible transparent electrodes based on mesh-patterned rigid indium tin oxide.

PubMed

Sakamoto, Kosuke; Kuwae, Hiroyuki; Kobayashi, Naofumi; Nobori, Atsuki; Shoji, Shuichi; Mizuno, Jun

2018-02-12

We developed highly bendable transparent indium tin oxide (ITO) electrodes with a mesh pattern for use in flexible electronic devices. The mesh patterns lowered tensile stress and hindered propagation of cracks. Simulations using the finite element method confirmed that the mesh patterns decreased tensile stress by over 10% because of the escaped strain to the flexible film when the electrodes were bent. The proposed patterned ITO electrodes were simply fabricated by photolithography and wet etching. The resistance increase ratio of a mesh-patterned ITO electrode after bending 1000 times was at least two orders of magnitude lower than that of a planar ITO electrode. In addition, crack propagation was stopped by the mesh pattern of the patterned ITO electrode. A mesh-patterned ITO electrode was used in a liquid-based organic light-emitting diode (OLED). The OLED displayed the same current density-voltage-luminance (J-V-L) curves before and after bending 100 times. These results indicate that the developed mesh-patterned ITO electrodes are attractive for use in flexible electronic devices.

THz conductivities of indium-tin-oxide nanowhiskers as a graded-refractive-index structure.

PubMed

Yang, Chan-Shan; Chang, Chia-Hua; Lin, Mao-Hsiang; Yu, Peichen; Wada, Osamu; Pan, Ci-Ling

2012-07-02

Indium-tin-oxide (ITO) nanowhiskers with attractive electrical and anti-reflection properties were prepared by the glancing-angle electron-beam evaporation technique. Structural and crystalline properties of such nanostructures were examined by scanning transmission electron microscopy and X-ray diffraction. Their frequency-dependent complex conductivities, refractive indices and absorption coefficients have been characterized with terahertz time-domain spectroscopy (THz-TDS), in which the nanowhiskers were considered as a graded-refractive-index (GRIN) structure instead of the usual thin film model. The electrical properties of ITO GRIN structures are analyzed and fitted well with Drude-Smith model in the 0.2~2.0 THz band. Our results indicate that the ITO nanowhiskers and its bottom layer atop the substrate exhibit longer carrier scattering times than ITO thin films. This signifies that ITO nanowhiskers have an excellent crystallinity with large grain size, consistent with X-ray data. Besides, we show a strong backscattering effect and fully carrier localization in the ITO nanowhiskers.

Effect of substrates on structural and optical properties of tin oxide (SnO2) nanostructures.

PubMed

Johari, Anima; Bhatnagar, M C; Rana, Vikas

2012-10-01

We report on controlling the morphology of tin oxide (SnO2) nanostructures and the study of the effect of surface morphology on structural and optical properties of SnO2 nanostuctures. In present work, Tin oxide (SnO2) nanostructures such as nanowires and nanorods have been grown by thermal evaporation of SnO2 powder. To demonstrate the effect of different substrates on the morphology of grown SnO2 nanostructures, the thermal evaporation of SnO2 powder was carried out on Si and gold catalyzed Si (Au/Si) substrates. The scanning-electron-microscopic analysis shows the growth of SnO2 nanowires on Au/Si substrate and growth of SnO2 nanorods on Si substrate. The scanning-and transmission-electron-microscopic analysis shows that the diameter of SnO2 nanowires and nanorods are about 70 nm and 95 nm respectively and their length is about 80 microm and 30 microm respectively. The vapor-liquid-solid (VLS) growth of SnO2 nanowires and vapor-solid (VS) growth of SnO2 nanorods is also confirmed with the help of TEM and EDX spectra. The synthesized SnO2 nanowires show tetragonal rutile structure of SnO2, whereas SnO2 nanorods show tetragonal rutile as well as cassiterite structure of SnO2. UV-Vis absorption spectra showed the optical band gaps of 4.1 eV and 3.8 eV for the SnO2 nanowires and the nanorods, respectively. The SnO2 nanowires and nanorods show photoluminescence with broad emission peaks centred at around 600 nm and 580 nm respectively. Raman spectra of SnO2 nanowires shows three Raman shifts (478, 632, 773 cm(-1)) corresponding to Eg, A1g and B2g vibration modes, whereas in Raman spectra of SnO2 nanorods, A1g peak is dramatically reduced and the B2g mode is totally quenched.

Gigahertz acoustic vibrations of elastically anisotropic Indium–tin-oxide nanorod arrays [Gigahertz modulation of the full visible spectrum via acoustic vibrations of elastically anisotropic Indium-tin-oxide nanorod arrays

DOE PAGES

Guo, Peijun; Schaller, Richard D.; Ocola, Leonidas E.; ...

2016-08-15

Active control of light is important for photonic integrated circuits, optical switches,. and telecommunications. Coupling light with acoustic vibrations in nanoscale optical resonators offers optical modulation capabilities with high bandwidth and Small footprint Instead of using noble metals, here we introduce indium tin-oxide nanorod arrays (ITO-NRAs) as the operating media;and demonstrate optical modulation covering the visible spectral range (from 360 to 700 nm), with similar to 20 GHz bandwidth through the excitation of coherent acoustic vibrations in ITO-NRAs. This broadband modulation results from the collective optical diffraction by the dielectric ITO-NRAs, and a high differential transmission modulation up to 10%more » is achieved through efficient near-infrared, on-plasmon-resonance pumping. By combining the frequency signatures Of the vibrational modes with finite-element simulations, we,further determine the anisotropic elastic constants for single-crystalline ITO, which are not known-for the bulk phase. Furthermore, this technique to determine elastic constants using Coherent acoustic vibrations of uniform nanostructures can be generalized to the study of other inorganic materials.« less

Gigahertz acoustic vibrations of elastically anisotropic Indium–tin-oxide nanorod arrays [Gigahertz modulation of the full visible spectrum via acoustic vibrations of elastically anisotropic Indium-tin-oxide nanorod arrays

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

Guo, Peijun; Schaller, Richard D.; Ocola, Leonidas E.

Active control of light is important for photonic integrated circuits, optical switches,. and telecommunications. Coupling light with acoustic vibrations in nanoscale optical resonators offers optical modulation capabilities with high bandwidth and Small footprint Instead of using noble metals, here we introduce indium tin-oxide nanorod arrays (ITO-NRAs) as the operating media;and demonstrate optical modulation covering the visible spectral range (from 360 to 700 nm), with similar to 20 GHz bandwidth through the excitation of coherent acoustic vibrations in ITO-NRAs. This broadband modulation results from the collective optical diffraction by the dielectric ITO-NRAs, and a high differential transmission modulation up to 10%more » is achieved through efficient near-infrared, on-plasmon-resonance pumping. By combining the frequency signatures Of the vibrational modes with finite-element simulations, we,further determine the anisotropic elastic constants for single-crystalline ITO, which are not known-for the bulk phase. Furthermore, this technique to determine elastic constants using Coherent acoustic vibrations of uniform nanostructures can be generalized to the study of other inorganic materials.« less

Catalytic process for formaldehyde oxidation

NASA Technical Reports Server (NTRS)

Kielin, Erik J. (Inventor); Brown, Kenneth G. (Inventor); D'Ambrosia, Christine M. (Inventor)

1996-01-01

Disclosed is a process for oxidizing formaldehyde to carbon dioxide and water without the addition of energy. A mixture of formaldehyde and an oxidizing agent (e.g., ambient air containing formaldehyde) is exposed to a catalyst which includes a noble metal dispersed on a metal oxide which possesses more than one oxidation state. Especially good results are obtained when the noble metal is platinum, and the metal oxide which possesses more than one oxidation state is tin oxide. A promoter (i.e., a small amount of an oxide of a transition series metal) may be used in association with the tin oxide to provide very beneficial results.

Improving the optoelectronic properties of titanium-doped indium tin oxide thin films

NASA Astrophysics Data System (ADS)

Taha, Hatem; Jiang, Zhong-Tao; Henry, David J.; Amri, Amun; Yin, Chun-Yang; Mahbubur Rahman, M.

2017-06-01

The focus of this study is on a sol-gel method combined with spin-coating to prepare high-quality transparent conducting oxide (TCO) films. The structural, morphological, optical and electrical properties of sol-gel-derived pure and Ti-doped indium tin oxide (ITO) thin films were studied as a function of the concentration of the Ti (i.e. 0 at%, 2 at% and 4 at%) and annealing temperatures (150 °C-600 °C). FESEM measurements indicate that all the films are ˜350 nm thick. XRD analysis confirmed the cubic bixbyite structure of the polycrystalline indium oxide phase for all of the thin films. Increasing the Ti ratio, as well as the annealing temperature, improved the crystallinity of the films. Highly crystalline structures were obtained at 500 °C, with average grain sizes of about 50, 65 and 80 nm for Ti doping of 0 at%, 2 at% and 4 at%, respectively. The electrical and optical properties improved as the annealing temperature increased, with an enlarged electronic energy band gap and an optical absorption edge below 280 nm. In particular, the optical transmittance and electrical resistivity of the samples with a 4 at% Ti content improved from 87% and 7.10 × 10-4 Ω.cm to 92% and 1.6 × 10-4 Ω.cm, respectively. The conductivity, especially for the annealing temperature at 150 °C, is acceptable for many applications such as flexible electronics. These results demonstrate that unlike the more expensive and complex vacuum sputtering process, high-quality Ti-doped ITO films can be achieved by fast processing, simple wet-chemistry, and easy doping level control with the possibility of producing films with high scalability.

Optimization of the Solution-Based Indium-Zinc Oxide/Zinc-Tin Oxide Channel Layer for Thin-Film Transistors.

PubMed

Lim, Kiwon; Choi, Pyungho; Kim, Sangsub; Kim, Hyunki; Kim, Minsoo; Lee, Jeonghyun; Hyeon, Younghwan; Koo, Kwangjun; Choi, Byoungdeog

2018-09-01

Double stacked indium-zinc oxide (IZO)/zinc-tin oxide (ZTO) active layers were employed in amorphous-oxide-semiconductor thin-film transistors (AOS TFTs). Channel layers of the TFTs were optimized by varying the molarity of ZTO back channel layers (0.05, 0.1, 0.2, 0.3 M) and the electrical properties of IZO/ZTO double stacked TFTs were compared to single IZO and ZTO TFTs with varying the molarity and molar ratio. On the basis of the results, IZO/ZTO (0.1 M) TFTs showed the excellent electrical properties of saturation mobility (13.6 cm2/V·s), on-off ratio (7×106), and subthreshold swing (0.223 V/decade) compared to ZTO (0.1 M) of 0.73 cm2/V · s, 1 × 107, 0.416 V/decade and IZO (0.04 M) of 0.10 cm2/V · s, 5 × 106, 0.60 V/decade, respectively. This may be attributed to diffusing Sn into front layer during annealing process. In addition, with varying molarity of ZTO back channel layer, from 0.1 M to 0.3 M ZTO back channel TFTs, electrical properties and positive bias stability deteriorated with increasing molarity of back channel layer because of increasing total trap states. On the other hand, 0.05 M ZTO back channel TFT had inferior electrical properties than that of 0.1 M ZTO back channel TFT. It was related to back channel effect because of having thin thickness of channel layer. Among these devices, 0.1 M ZTO back channel TFT had a lowest total trap density, outstanding electrical properties and stability. Therefore, we recommended IZO/ZTO (0.1 M) TFT as a promising channel structure for advanced display applications.

Tin Whisker Growth and Mitigation with a Nanocrysytalline Nickel Coating

NASA Astrophysics Data System (ADS)

Janiuk, Szymon

Tin whiskers are a problem in the electronics industry since the EU banned the use of lead in Pb-Sn solders as part of the Restriction of Hazardous Substances (RoHS). The biggest concern with Sn whiskers is their ability to short-circuit electronics. High reliability applications such as the aerospace, defense, healthcare, and automotive industries are at most risk. This project explores Sn whisker mitigation and prevention with the use of nanocrystalline nickel coating over Sn surfaces. Sn was plated onto a pure Cu substrate using electroplating. A high temperature and high humidity condition, at 85°C and 85% RH, was effective at growing whiskers. A nNi coating was plated over Sn/Cu coupons. After subjecting the nNi/ Sn/Cu samples through 85°C/85% RH testing conditions, no whiskers were observed penetrating the surface. These results make nNi a viable material to use as a coating to prevent the growth of Sn whiskers in electronic assemblies.

Metal-induced crystallization of amorphous zinc tin oxide semiconductors for high mobility thin-film transistors

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

Hwang, Ah Young; Ji, Hyuk; Kim, Sang Tae

2016-04-11

Transition tantalum induced crystallization of amorphous zinc tin oxide (a-ZTO) was observed at low temperature annealing of 300 °C. Thin-film transistors (TFTs) with an a-ZTO channel layer exhibited a reasonable field-effect mobility of 12.4 cm{sup 2}/V s, subthreshold swing (SS) of 0.39 V/decade, threshold voltage (V{sub TH}) of 1.5 V, and I{sub ON/OFF} ratio of ∼10{sup 7}. A significant improvement in the field-effect mobility (up to ∼33.5 cm{sup 2}/V s) was achieved for crystallized ZTO TFTs: this improvement was accomplished without compromising the SS, V{sub TH}, or I{sub ON/OFF} ratio due to the presence of a highly ordered microstructure.

The role of Tin Oxide Concentration on The X-ray Diffraction, Morphology and Optical Properties of In2O3:SnO2 Thin Films

NASA Astrophysics Data System (ADS)

Hasan, Bushra A.; Abdallah, Rusul M.

2018-05-01

Alloys were performed from In2O3 doped SnO2 with different doping ratio by quenching from the melt technique. Pulsed Laser Deposition PLD was used to deposit thin films of different doping ratio In2O3 : SnO2 (0, 1, 3, 5, 7 and 9 % wt.) on glass substrate at ambient temperature under vacuum of 10-3 bar thickness of ∼100nm. The structural type,grain size and morphology of the prepared alloys compounds and thin films were examined using X-ray diffraction and atomic force microscopy. The results showed that all alloys have polycrystalline structures and the peaks belonged to the preferred plane for crystal growth were identical with the ITO (Indium – Tin –Oxide) standard cards also another peaks were observed belonged to SnO2 phase. The structures of thin films was also polycrystalline, and the predominate peaks are identical with standard cards ITO. On the other side the prepared thin films declared decrease a reduction of degree of crystallinity with the increase of doping ratio. Atomic Force Microscopy AFM measurements showed the average grain size and average surface roughness exhibit to change in systematic manner with the increase of doping ratio with tin oxide. The optical measurements show that the In2O3:SnO2 thin films have a direct energy gap Eg opt in the first stage decreases with the increase of doping ratio and then get to increase with further increase of doping ration, whereas reverse to that the optical constants such as refractive index (n), extinction coefficient (k) and dielectric constant (εr, εi) have a regular increase with the doping ratio by tin oxide and then decreases.

Determination of trace amounts of tin in geological materials by atomic absorption spectrometry

USGS Publications Warehouse

Welsch, E.P.; Chao, T.T.

1976-01-01

An atomic absorption method is described for the determination of traces of tin in rocks, soils, and stream sediments. A dried mixture of the sample and ammonium iodide is heated to volatilize tin tetraiodide -which is then dissolved in 5 % hydrochloric acid, extracted into TOPO-MIBK, and aspirated into a nitrous oxide-acetylene flame. The limit of determination is 2 p.p.m. tin and the relative standard deviation ranges from 2 to 14 %. Up to 20 % iron and 1000 p.p.m. Cu, Pb, Zn, Mn, Hg, Mo, V, or W in the sample do not interfere. As many as 50 samples can be easily analyzed per man-day. ?? 1976.

Pourbaix Diagrams at Elevated Temperatures A Study of Zinc and Tin

NASA Astrophysics Data System (ADS)

Palazhchenko, Olga

Metals in industrial settings such as power plants are often subjected to high temperature and pressure aqueous environments, where failure to control corrosion compromises worker and environment safety. For instance, zircaloy (1.2-1.7 wt.% Sn) fuel rods are exposed to aqueous 250-310 °C coolant in CANDU reactors. The Pourbaix (EH-pH) diagram is a plot of electrochemical potential versus pH, which shows the domains of various metal species and by inference, corrosion susceptibility. Elevated temperature data for tin +II and tin +IV species were obtained using solid-aqueous phase equilibria with the respective oxides, in a batch vessel with in-situ pH measurement. Solubilities, determined via spectroscopic techniques, were used to calculate equilibrium constants and the Gibbs energies of Sn complexes for E-pH diagram construction. The SnOH3+ and Sn(OH )-5 species were incorporated, for the first time, into the 298.15 K and 358.15 K diagrams, with novel Go values determined at 358.15 K. Key words: Pourbaix diagrams, EH-pH, elevated temperatures, solubility, equilibrium, metal oxides, hydrolysis, redox potential, pH, thermochemical data, tin, zinc, zircaloy, corrosion, passivity.

Lithium intercalation in sputter deposited antimony-doped tin oxide thin films: Evidence from electrochemical and optical measurements

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

Montero, J., E-mail: jose.montero@angstrom.uu.se; Granqvist, C. G.; Niklasson, G. A.

2014-04-21

Transparent conducting oxides are used as transparent electrical contacts in a variety of applications, including in electrochromic smart windows. In the present work, we performed a study of transparent conducting antimony-doped tin oxide (ATO) thin films by chronopotentiometry in a Li{sup +}-containing electrolyte. The open circuit potential vs. Li was used to investigate ATO band lineups, such as those of the Fermi level and the ionization potential, as well as the dependence of these lineups on the preparation conditions for ATO. Evidence was found for Li{sup +} intercalation when a current pulse was set in a way so as tomore » drive ions from the electrolyte into the ATO lattice. Galvanostatic intermittent titration was then applied to determine the lithium diffusion coefficient within the ATO lattice. The electrochemical density of states of the conducting oxide was studied by means of the transient voltage recorded during the chronopotentiometry experiments. These measurements were possible because, as Li{sup +} intercalation took place, charge compensating electrons filled the lowest part of the conduction band in ATO. Furthermore, the charge insertion modified the optical properties of ATO according to the Drude model.« less

Efficient indium-tin-oxide free inverted organic solar cells based on aluminum-doped zinc oxide cathode and low-temperature aqueous solution processed zinc oxide electron extraction layer

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

Chen, Dazheng; Zhang, Chunfu, E-mail: cfzhang@xidian.edu.cn; Wang, Zhizhe

Indium-tin-oxide (ITO) free inverted organic solar cells (IOSCs) based on aluminum-doped zinc oxide (AZO) cathode, low-temperature aqueous solution processed zinc oxide (ZnO) electron extraction layer, and poly(3-hexylthiophene-2, 5-diyl):[6, 6]-phenyl C{sub 61} butyric acid methyl ester blend were realized in this work. The resulted IOSC with ZnO annealed at 150 °C shows the superior power conversion efficiency (PCE) of 3.01%, if decreasing the ZnO annealing temperature to 100 °C, the obtained IOSC also shows a PCE of 2.76%, and no light soaking issue is observed. It is found that this ZnO film not only acts as an effective buffer layer but also slightlymore » improves the optical transmittance of AZO substrates. Further, despite the relatively inferior air-stability, these un-encapsulated AZO/ZnO IOSCs show comparable PCEs to the referenced ITO/ZnO IOSCs, which demonstrates that the AZO cathode is a potential alternative to ITO in IOSCs. Meanwhile, this simple ZnO process is compatible with large area deposition and plastic substrates, and is promising to be widely used in IOSCs and other relative fields.« less

Wear of tin coating and Al-Si alloy substrate against carburized steel under mixed lubrication

NASA Astrophysics Data System (ADS)

Wang, Q.; Cheng, H. S.; Fine, M. E.

1994-04-01

Tin coatings on Al-Si alloys are widely used in the automotive industries. The soft tin coating and the harder substrate alloy form a tribological system with the advantages of low friction and reasonably high load-bearing capacity. Wear tests of tin coated Al-Si Z332 alloy in conformal contact against carburized 1016 steel have been carried out under mixed lubrications with SAE 10W30 oil to study the wear mechanisms. Two major wear mechanisms, uniform wear of the tin coating due to micro-plowing and spall pitting related to the substrate are found to contribute to the bearing material loss when the fluid lubrication film is relatively thick (Lambda about 1.6). Under conditions of thinner films (Lambda approximately = 0.8), some local coating debonding occurs. The pitting and local coating debounding are closely related to fracture in the substrate. The bonding between silicon and tin seems to be weaker than between aluminum and tin. During wear, oxidation occurs.

Indium tin oxide nanopillar electrodes in polymer/fullerene solar cells.

PubMed

Rider, David A; Tucker, Ryan T; Worfolk, Brian J; Krause, Kathleen M; Lalany, Abeed; Brett, Michael J; Buriak, Jillian M; Harris, Kenneth D

2011-02-25

Using high surface area nanostructured electrodes in organic photovoltaic (OPV) devices is a route to enhanced power conversion efficiency. In this paper, indium tin oxide (ITO) and hybrid ITO/SiO(2) nanopillars are employed as three-dimensional high surface area transparent electrodes in OPVs. The nanopillar arrays are fabricated via glancing angle deposition (GLAD) and electrochemically modified with nanofibrous PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly(p-styrenesulfonate)). The structures are found to have increased surface area as characterized by porosimetry. When applied as anodes in polymer/fullerene OPVs (architecture: commercial ITO/GLAD ITO/PEDOT:PSS/P3HT:PCBM/Al, where P3HT is 2,5-diyl-poly(3-hexylthiophene) and PCBM is [6,6]-phenyl-C(61)-butyric acid methyl ester), the air-processed solar cells incorporating high surface area, PEDOT:PSS-modified ITO nanoelectrode arrays operate with improved performance relative to devices processed identically on unstructured, commercial ITO substrates. The resulting power conversion efficiency is 2.2% which is a third greater than for devices prepared on commercial ITO. To further refine the structure, insulating SiO(2) caps are added above the GLAD ITO nanopillars to produce a hybrid ITO/SiO(2) nanoelectrode. OPV devices based on this system show reduced electrical shorting and series resistance, and as a consequence, a further improved power conversion efficiency of 2.5% is recorded.

Cooperative tin oxide fullerene electron selective layers for high-performance planar perovskite solar cells

DOE PAGES

Ke, Weijun; Zhao, Dewei; Xiao, Chuanxiao; ...

2016-08-17

Both tin oxide (SnO 2) and fullerenes have been reported as electron selective layers (ESLs) for producing efficient lead halide perovskite solar cells. Here, we report that SnO 2 and fullerenes can work cooperatively to further boost the performance of perovskite solar cells. We find that fullerenes can be redissolved during perovskite deposition, allowing ultra-thin fullerenes to be retained at the interface and some dissolved fullerenes infiltrate into perovskite grain boundaries. The SnO 2 layer blocks holes effectively; whereas, the fullerenes promote electron transfer and passivate both the SnO 2/perovskite interface and perovskite grain boundaries. With careful device optimization, themore » best-performing planar perovskite solar cell using a fullerene passivated SnO 2 ESL has achieved a steady-state efficiency of 17.75% and a power conversion efficiency of 19.12% with an open circuit voltage of 1.12 V, a short-circuit current density of 22.61 mA cm -2, and a fill factor of 75.8% when measured under reverse voltage scanning. In conclusion, we find that the partial dissolving of fullerenes during perovskite deposition is the key for fabricating high-performance perovskite solar cells based on metal oxide/fullerene ESLs.« less

Evaluation of metal/indium-tin-oxide for transparent low-resistance contacts to p-type GaN.

PubMed

Hou, Wenting; Stark, Christoph; You, Shi; Zhao, Liang; Detchprohm, Theeradetch; Wetzel, Christian

2012-08-10

In search of a better transparent contact to p-GaN, we analyze various metal/indium-tin-oxide (ITO) (Ag/ITO, AgCu/ITO, Ni/ITO, and NiZn/ITO) contact schemes and compare to Ni/Au, NiZn/Ag, and ITO. The metal layer boosts conductivity while the ITO thickness can be adjusted to constructive transmission interference on GaN that exceeds extraction from bare GaN. We find a best compromise for an Ag/ITO (3 nm/67 nm) ohmic contact with a relative transmittance of 97% of the bare GaN near 530 nm and a specific contact resistance of 0.03 Ω·cm2. The contact proves suitable for green light-emitting diodes in epi-up geometry.

Fabrication and performance analysis of 4-sq cm indium tin oxide/InP photovoltaic solar cells

NASA Technical Reports Server (NTRS)

Gessert, T. A.; Li, X.; Phelps, P. W.; Coutts, T. J.; Tzafaras, N.

1991-01-01

Large-area photovoltaic solar cells based on direct current magnetron sputter deposition of indium tin oxide (ITO) into single-crystal p-InP substrates demonstrated both the radiation hardness and high performance necessary for extraterrestrial applications. A small-scale production project was initiated in which approximately 50 ITO/InP cells are being produced. The procedures used in this small-scale production of 4-sq cm ITO/InP cells are presented and discussed. The discussion includes analyses of performance range of all available production cells, and device performance data of the best cells thus far produced. Additionally, processing experience gained from the production of these cells is discussed, indicating other issues that may be encountered when large-scale productions are begun.

Reaction Mechanisms of the Atomic Layer Deposition of Tin Oxide Thin Films Using Tributyltin Ethoxide and Ozone.

PubMed

Nanayakkara, Charith E; Liu, Guo; Vega, Abraham; Dezelah, Charles L; Kanjolia, Ravindra K; Chabal, Yves J

2017-06-20

Uniform and conformal deposition of tin oxide thin films is important for several applications in electronics, gas sensing, and transparent conducting electrodes. Thermal atomic layer deposition (ALD) is often best suited for these applications, but its implementation requires a mechanistic understanding of the initial nucleation and subsequent ALD processes. To this end, in situ FTIR and ex situ XPS have been used to explore the ALD of tin oxide films using tributyltin ethoxide and ozone on an OH-terminated, SiO 2 -passivated Si(111) substrate. Direct chemisorption of tributyltin ethoxide on surface OH groups and clear evidence that subsequent ligand exchange are obtained, providing mechanistic insight. Upon ozone pulse, the butyl groups react with ozone, forming surface carbonate and formate. The subsequent tributyltin ethoxide pulse removes the carbonate and formate features with the appearance of the bands for CH stretching and bending modes of the precursor butyl ligands. This ligand-exchange behavior is repeated for subsequent cycles, as is characteristic of ALD processes, and is clearly observed for deposition temperatures of 200 and 300 °C. On the basis of the in situ vibrational data, a reaction mechanism for the ALD process of tributyltin ethoxide and ozone is presented, whereby ligands are fully eliminated. Complementary ex situ XPS depth profiles confirm that the bulk of the films is carbon-free, that is, formate and carbonate are not incorporated into the film during the deposition process, and that good-quality SnO x films are produced. Furthermore, the process was scaled up in a cross-flow reactor at 225 °C, which allowed the determination of the growth rate (0.62 Å/cycle) and confirmed a self-limiting ALD growth at 225 and 268 °C. An analysis of the temperature-dependence data reveals that growth rate increases linearly between 200 and 300 °C.

Fabrication of Highly Ordered and Well-Aligned PbTiO 3/TiN Core–Shell Nanotube Arrays

DOE PAGES

Yoon, Jaesung; Kim, Sangjoon; Kim, Dongjin; ...

2015-04-30

Highly ordered and well-aligned PbTiO 3/TiN core–shell nanotubes are fabricated in this paper via an anodic aluminum oxide templating route followed by TiN and TiO 2 atomic layer deposition deposition and a subsequent PbO vapor reaction. Finally, PbTiO 3/TiN nanotubes keep their original shape after the vapor phase reaction, and they display well-defined piezoresponse hysteresis curves with remnant piezoresponse of 38 pm V -1.

Metal oxide nanorod arrays on monolithic substrates

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

Gao, Pu-Xian; Guo, Yanbing; Ren, Zheng

A metal oxide nanorod array structure according to embodiments disclosed herein includes a monolithic substrate having a surface and multiple channels, an interface layer bonded to the surface of the substrate, and a metal oxide nanorod array coupled to the substrate surface via the interface layer. The metal oxide can include ceria, zinc oxide, tin oxide, alumina, zirconia, cobalt oxide, and gallium oxide. The substrate can include a glass substrate, a plastic substrate, a silicon substrate, a ceramic monolith, and a stainless steel monolith. The ceramic can include cordierite, alumina, tin oxide, and titania. The nanorod array structure can includemore » a perovskite shell, such as a lanthanum-based transition metal oxide, or a metal oxide shell, such as ceria, zinc oxide, tin oxide, alumina, zirconia, cobalt oxide, and gallium oxide, or a coating of metal particles, such as platinum, gold, palladium, rhodium, and ruthenium, over each metal oxide nanorod. Structures can be bonded to the surface of a substrate and resist erosion if exposed to high velocity flow rates.« less

Superior local conductivity in self-organized nanodots on indium-tin-oxide films induced by femtosecond laser pulses.

PubMed

Wang, Chih; Wang, Hsuan-I; Tang, Wei-Tsung; Luo, Chih-Wei; Kobayashi, Takayoshi; Leu, Jihperng

2011-11-21

Large-area surface ripple structures of indium-tin-oxide films, composed of self-organized nanodots, were induced by femtosecond laser pulses, without scanning. The multi-periodic spacing (~800 nm, ~400 nm and ~200 nm) was observed in the laser-induced ripple of ITO films. The local conductivity of ITO films is significantly higher, by approximately 30 times, than that of the as-deposited ITO films, due to the formation of these nanodots. Such a significant change can be ascribed to the formation of indium metal-like clusters, which appear as budges of ~5 nm height, due to an effective volume increase after breaking the In-O to form In-In bonding. © 2011 Optical Society of America

Solid state consolidation nanocrystalline copper-tungsten using cold spray

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

Hall, Aaron Christopher; Sarobol, Pylin; Argibay, Nicolas

It is well known that nanostructured metals can exhibit significantly improved properties compared to metals with conventional grain size. Unfortunately, nanocrystalline metals typically are not thermodynamically stable and exhibit rapid grain growth at moderate temperatures. This severely limits their processing and use, making them impractical for most engineering applications. Recent work has shown that a number of thermodynamically stable nanocrystalline metal alloys exist. These alloys have been prepared as powders using severe plastic deformation (e.g. ball milling) processes. Consolidation of these powders without compromise of their nanocrystalline microstructure is a critical step to enabling their use as engineering materials. Wemore » demonstrate solid-state consolidation of ball milled copper-tantalum nanocrystalline metal powder using cold spray. Unfortunately, the nanocrystalline copper-tantalum powder that was consolidated did not contain the thermodynamically stable copper-tantalum nanostructure. Nevertheless, this does this demonstrates a pathway to preparation of bulk thermodynamically stable nanocrystalline copper-tantalum. Furthermore, it demonstrates a pathway to additive manufacturing (3D printing) of nanocrystalline copper-tantalum. Additive manufacturing of thermodynamically stable nanocrystalline metals is attractive because it enables maximum flexibility and efficiency in the use of these unique materials.« less

Preparation and photovoltaic properties of CdS quantum dot-sensitized solar cell based on zinc tin mixed metal oxides.

PubMed

Cao, Jiupeng; Zhao, Yifan; Zhu, Yatong; Yang, Xiaoyu; Shi, Peng; Xiao, Hongdi; Du, Na; Hou, Wanguo; Qi, Genggeng; Liu, Jianqiang

2017-07-15

The present study reports a new type of quantum dot sensitized solar cells (QDSSCs) using the zinc tin mixed metal oxides (MMO) as the anode materials, which were obtained from the layered double hydroxide (LDH) precursor. The successive ionic layer adsorption and reaction (SILAR) method is applied to deposit CdS quantum dots. The effects of sensitizing cycles on the performance of CdS QDSSC are studied. Scanning electron microscopy (SEM), Transmission electron microscope (TEM) and X-ray diffraction (XRD) are used to identify the surface profile and crystal structure of the mixed metal oxides anode. The photovoltaic performance of the QDSSC is studied by the electrochemical method. The new CdS QDSSC exhibits power conversion efficiency (PCE) up to 0.48% when the anode was sensitized for eight cycles. Copyright © 2017 Elsevier Inc. All rights reserved.

Broader color gamut of color-modulating optical coating display based on indium tin oxide and phase change materials.

PubMed

Ni, Zhigang; Mou, Shenghong; Zhou, Tong; Cheng, Zhiyuan

2018-05-01

A color-modulating optical coating display based on phase change materials (PCM) and indium tin oxide (ITO) is fabricated and analyzed. We demonstrate that altering the thickness of top-ITO in this PCM-based display device can effectively change color. The significant role of the top-ITO layer in the thin-film interference in this multilayer system is confirmed by experiment as well as simulation. The ternary-color modulation of devices with only 5 nano thin layer of phase change material is achieved. Furthermore, simulation work demonstrates that a stirringly broader color gamut can be obtained by introducing the control of the top-ITO thickness.

Direct imprinting of indium-tin-oxide precursor gel and simultaneous formation of channel and source/drain in thin-film transistor

NASA Astrophysics Data System (ADS)

Haga, Ken-ichi; Kamiya, Yuusuke; Tokumitsu, Eisuke

2018-02-01

We report on a new fabrication process for thin-film transistors (TFTs) with a new structure and a new operation principle. In this process, both the channel and electrode (source/drain) are formed simultaneously, using the same oxide material, using a single nano-rheology printing (n-RP) process, without any conventional lithography process. N-RP is a direct thermal imprint technique and deforms oxide precursor gel. To reduce the source/drain resistance, the material common to the channel and electrode is conductive indium-tin-oxide (ITO). The gate insulator is made of a ferroelectric material, whose high charge density can deplete the channel of the thin ITO film, which realizes the proposed operation principle. First, we have examined the n-RP conditions required for the channel and source/drain patterning, and found that the patterning properties are strongly affected by the cooling rate before separating the mold. Second, we have fabricated the TFTs as proposed and confirmed their TFT operation.

Potential of tin (IV) chloride for treatment in Alor Pongsu as stabilized landfill leachate

NASA Astrophysics Data System (ADS)

Zainal, Sharifah Farah Fariza Syed; Aziz, Hamidi Abdul

2017-10-01

Leachate production from landfilling contributes crucial pollutants to the environment. This study examined the potential of tin (IV) chloride as coagulant that involved charge neutralization and sweep flocculation mechanisms. The negative charge of leachate is neutralized by adding tin (IV) chloride as cationic coagulant which resulted precipitation and swept most of the colloids and dissolved solids that entrapped in the settling as hydrous oxide floc. Parameters such as suspended solid (SS) content, color, and chemical oxygen demand (COD) were analyzed using standard jar test procedures. The best condition was observed at pH 8, with removal efficiencies of 75.99 %, 99.29 % and 98.36 % for COD, SS, and color, respectively. At optimum dosage, tin (IV) chloride successfully removed 98.40 % for color, 99.54 % for SS and 71.53 % for COD. These results indicated the satisfactory performance of tin (IV) chloride. Hence, tin (IV) chloride is a potential coagulant for the treatment of Alor Pongsu Landfill leachate.

Fabrication of flexible indium tin oxide-free polymer solar cells with silver nanowire transparent electrode

NASA Astrophysics Data System (ADS)

Lin, Ming-Yi; Chen, Tsun-Jui; Xu, Wei-Feng; Hsiao, Li-Jen; Budiawan, Widhya; Tu, Wei-Chen; Chen, Shih-Lun; Chu, Chih-Wei; Wei, Pei-Kuen

2018-03-01

Flexible indium tin oxide (ITO)-free poly(3-hexylthiophene):[6,6]-phenyl C61-butyric acid methyl ester (P3HT:PC61BM) solar cells with a spin-coated silver nanowire transparent electrode are demonstrated. The solution-processed silver nanowire thin film not only exhibits high transmission (∼87%), but also shows low sheet resistance R s (∼25 Ω/sq). For solar cells with a conventional structure, the power conversion efficiency (PCE) of devices based on silver nanowires can reach around 2.29%. For the inverted structure, the PCE of devices can reach 3.39%. Conventional and inverted flexible ITO-based P3HT:PC61BM solar cells are also fabricated as a reference for comparison. For both types of solar cells, the PCE of ITO-free devices is very close that of an ITO-based polymer solar cell.

Solubility of indium-tin oxide in simulated lung and gastric fluids: Pathways for human intake.

PubMed

Andersen, Jens Christian Østergård; Cropp, Alastair; Paradise, Diane Caroline

2017-02-01

From being a metal with very limited natural distribution, indium (In) has recently become disseminated throughout the human society. Little is known of how In compounds behave in the natural environment, but recent medical studies link exposure to In compounds to elevated risk of respiratory disorders. Animal tests suggest that exposure may lead to more widespread damage in the body, notably the liver, kidneys and spleen. In this paper, we investigate the solubility of the most widely used In compound, indium-tin oxide (ITO) in simulated lung and gastric fluids in order to better understand the potential pathways for metals to be introduced into the bloodstream. Our results show significant potential for release of In and tin (Sn) in the deep parts of the lungs (artificial lysosomal fluid) and digestive tract, while the solubility in the upper parts of the lungs (the respiratory tract or tracheobronchial tree) is very low. Our study confirms that ITO is likely to remain as solid particles in the upper parts of the lungs, but that particles are likely to slowly dissolve in the deep lungs. Considering the prolonged residence time of inhaled particles in the deep lung, this environment is likely to provide the major route for uptake of In and Sn from inhaled ITO nano- and microparticles. Although dissolution through digestion may also lead to some uptake, the much shorter residence time is likely to lead to much lower risk of uptake. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Ag-Pd-Cu alloy inserted transparent indium tin oxide electrodes for organic solar cells

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

Kim, Hyo-Joong; Seo, Ki-Won; Kim, Han-Ki, E-mail: imdlhkkim@khu.ac.kr

2014-09-01

The authors report on the characteristics of Ag-Pd-Cu (APC) alloy-inserted indium tin oxide (ITO) films sputtered on a glass substrate at room temperature for application as transparent anodes in organic solar cells (OSCs). The effect of the APC interlayer thickness on the electrical, optical, structural, and morphological properties of the ITO/APC/ITO multilayer were investigated and compared to those of ITO/Ag/ITO multilayer electrodes. At the optimized APC thickness of 8 nm, the ITO/APC/ITO multilayer exhibited a resistivity of 8.55 × 10{sup −5} Ω cm, an optical transmittance of 82.63%, and a figure-of-merit value of 13.54 × 10{sup −3} Ω{sup −1}, comparable to those of the ITO/Ag/ITOmore » multilayer. Unlike the ITO/Ag/ITO multilayer, agglomeration of the metal interlayer was effectively relieved with APC interlayer due to existence of Pd and Cu elements in the thin region of the APC interlayer. The OSCs fabricated on the ITO/APC/ITO multilayer showed higher power conversion efficiency than that of OSCs prepared on the ITO/Ag/ITO multilayer below 10 nm due to the flatness of the APC layer. The improved performance of the OSCs with ITO/APC/ITO multilayer electrodes indicates that the APC alloy interlayer prevents the agglomeration of the Ag-based metal interlayer and can decrease the thickness of the metal interlayer in the oxide-metal-oxide multilayer of high-performance OSCs.« less

Influence of Direct Current Electric Field on Corrosion Behavior of Tin Under a Thin Electrolyte Layer

NASA Astrophysics Data System (ADS)

Huang, H. L.; Bu, F. R.; Tian, J.; Liu, D.

2017-12-01

The influence of a direct current electric field (DCEF) on corrosion behavior of tin under a thin electrolyte layer was investigated based on an array electrode technology by polarization, electrochemical impedance spectroscopy and surface analysis. The experimental results indicate that the corrosion rate of tin near the positive plate of DCEF increases with increased electric field intensity, which could be attributed to the acceleration of the migration of ions, the removal of corrosion products under DCEF and the damage of tin surface oxide film. Furthermore, tin at different positions in a DCEF exhibits different corrosion behavior, which could be ascribed to the difference of the local corrosion environment caused by the DCEF.

Effect of solvent volume on the physical properties of undoped and fluorine doped tin oxide films deposited using a low-cost spray technique

NASA Astrophysics Data System (ADS)

Muruganantham, G.; Ravichandran, K.; Saravanakumar, K.; Ravichandran, A. T.; Sakthivel, B.

2011-12-01

Undoped and fluorine doped tin oxide films were deposited from starting solutions having different values of solvent volume (10-50 ml) by employing a low cost and simplified spray technique using perfume atomizer. X-ray diffraction studies showed that there was a change in the preferential orientation from (2 1 1) plane to (1 1 0) plane as the volume of the solvent was increased. The sheet resistance ( Rsh) of undoped SnO 2 film was found to be minimum (13.58 KΩ/□) when the solvent volume was lesser (10 ml) and there was a sharp increase in Rsh for higher values of solvent volume. Interestingly, it was observed that while the Rsh increases sharply with the increase in solvent volume for undoped SnO 2 films, it decreases gradually in the case of fluorine doped SnO 2 films. The quantitative analysis of EDAX confirmed that the electrical resistivity of the sprayed tin oxide film was mainly governed by the number of oxygen vacancies and the interstitial incorporation of Sn atoms which in turn was governed by the impinging flux on the hot substrate. The films were found to have good optical characteristics suitable for opto-electronic devices.

Indium tin oxide based chip for optical and electrochemical characterization of protein-cell interaction

NASA Astrophysics Data System (ADS)

Choi, Yong Hyun; Min, Junhong; Cho, Sungbo

2015-06-01

Analysis on the interaction between proteins and cells is required for understanding the cellular behaviour and response. In this article, we characterized the adhesion and growth of 293/GFP cells on fetal bovine serum (FBS) coated indium tin oxide (ITO) electrode. Using optical and electrochemical measurement, it was able to detect the adsorption of the protein on the surface of the ITO electrode dependent on the concentration of the protein in the immersing solution or the immersing time. An increase in the amount of the adsorbed serum protein resulted in a decrease in anodic peak current and an increase in the charge transfer resistance extracted from the equivalent circuit fitting analysis. More cells adhered and proliferated on the ITO electrode which was pre-immersed in FBS medium rather than bare electrode. The effect of the FBS on cell behaviors was reflected in the impedance monitoring of cells at 21.5 kHz.

Direct transparent electrode patterning on layered GaN substrate by screen printing of indium tin oxide nanoparticle ink for Eu-doped GaN red light-emitting diode

NASA Astrophysics Data System (ADS)

Kashiwagi, Y.; Koizumi, A.; Takemura, Y.; Furuta, S.; Yamamoto, M.; Saitoh, M.; Takahashi, M.; Ohno, T.; Fujiwara, Y.; Murahashi, K.; Ohtsuka, K.; Nakamoto, M.

2014-12-01

Transparent electrodes were formed on Eu-doped GaN-based red-light-emitting diode (GaN:Eu LED) substrates by the screen printing of indium tin oxide nanoparticle (ITO np) inks as a wet process. The ITO nps with a mean diameter of 25 nm were synthesized by the controlled thermolysis of a mixture of indium complexes and tin complexes. After the direct screen printing of ITO np inks on GaN:Eu LED substrates and sintering at 850 °C for 10 min under atmospheric conditions, the resistivity of the ITO film was 5.2 mΩ cm. The fabricated LED up to 3 mm square surface emitted red light when the on-voltage was exceeded.

Study of tin amalgam mirrors by 1 1 9 Sn Mössbauer spectroscopy and other analytical methods

NASA Astrophysics Data System (ADS)

Lerf, A.; Wagner, F. E.; Herrera, L. K.; Justo, A.; Mu noz-Páez, A.; Pérez-Rodríguez, J. L.

2016-12-01

From the beginning of the 16 th until the end of the 19 th century the most widely used mirrors consisted of a pane of glass backed with a reflecting layer of tin-mercury amalgam. They were made by sliding the glass pane over a tin foil covered with liquid mercury. After removal of the superfluous mercury, tin amalgam formed slowly at ambient temperature and yielded a reflecting layer adhering to the surface of the glass. Such mirrors often deteriorate in the course of time by oxidation of the tin in the amalgam to stannous or stannic oxide. 119Sn Mössbauer spectroscopy, scanning electron microscopy, micro-XRF and X-ray diffraction have been used to study this deterioration process. The studied specimens were a modern mirror made for the reconstruction of the Green Vault in Dresden in the early 2000s, two rather well preserved German mirrors from the 17 th and 19 th centuries and several strongly deteriorated specimens of Baroque mirrors from the south of Spain. The modern mirror consists mainly of a Sn0.9Hg0.1 amalgam with only 2 % of SnO2. The older German mirrors showed more pronounced oxidation, containing 12 and 15 % of SnO2, which did not noticeably impair their reflectivity. In the samples from the Spanish mirrors at best a few percent of metallic phase was left. The majority of the tin had oxidised to SnO2, but between 8 and 20 % of the tin was present as SnO. X-ray diffraction yielded similar results and micro-XRF mapping using synchrotron radiation for excitation gave information on the distribution of Sn and Hg in the reflecting layer of the mirrors.

Micromechanics Modeling of Fracture in Nanocrystalline Metals

NASA Technical Reports Server (NTRS)

Glaessgen, E. H.; Piascik, R. S.; Raju, I. S.; Harris, C. E.

2002-01-01

Nanocrystalline metals have very high theoretical strength, but suffer from a lack of ductility and toughness. Therefore, it is critical to understand the mechanisms of deformation and fracture of these materials before their full potential can be achieved. Because classical fracture mechanics is based on the comparison of computed fracture parameters, such as stress intlmsity factors, to their empirically determined critical values, it does not adequately describe the fundamental physics of fracture required to predict the behavior of nanocrystalline metals. Thus, micromechanics-based techniques must be considered to quanti@ the physical processes of deformation and fracture within nanocrystalline metals. This paper discusses hndamental physicsbased modeling strategies that may be useful for the prediction Iof deformation, crack formation and crack growth within nanocrystalline metals.

Controlling plasmonic properties of epitaxial thin films of indium tin oxide in the near-infrared region

NASA Astrophysics Data System (ADS)

Kamakura, R.; Fujita, K.; Murai, S.; Tanaka, K.

2015-06-01

Epitaxial thin films of indium tin oxide (ITO) were grown on yttria-stabilized zirconia single-crystal substrates by using a pulsed laser deposition to examine their plasmonic properties. The dielectric function of ITO was characterized by spectroscopic ellipsometry. Through the concentration of SnO2 in the target, the carrier concentration in the films was modified, which directly leads to the tuning of the dielectric function in the near-infrared region. Variable-angle reflectance spectroscopy in the Kretschmann geometry shows the dip in the reflection spectrum of p-polarized light corresponding to the excitation of surface plasmon polaritions (SPPs) in the near-infrared region. The excitation wavelength of the SPPs was shifted with changing the dielectric functions of ITO, which is reproduced by the calculation using transfer matrix method.

Effective Electrochemistry of Human Sulfite Oxidase Immobilized on Quantum-Dots-Modified Indium Tin Oxide Electrode.

PubMed

Zeng, Ting; Leimkühler, Silke; Koetz, Joachim; Wollenberger, Ulla

2015-09-30

The bioelectrocatalytic sulfite oxidation by human sulfite oxidase (hSO) on indium tin oxide (ITO) is reported, which is facilitated by functionalizing of the electrode surface with polyethylenimine (PEI)-entrapped CdS nanoparticles and enzyme. hSO was assembled onto the electrode with a high surface loading of electroactive enzyme. In the presence of sulfite but without additional mediators, a high bioelectrocatalytic current was generated. Reference experiments with only PEI showed direct electron transfer and catalytic activity of hSO, but these were less pronounced. The application of the polyelectrolyte-entrapped quantum dots (QDs) on ITO electrodes provides a compatible surface for enzyme binding with promotion of electron transfer. Variations of the buffer solution conditions, e.g., ionic strength, pH, viscosity, and the effect of oxygen, were studied in order to understand intramolecular and heterogeneous electron transfer from hSO to the electrode. The results are consistent with a model derived for the enzyme by using flash photolysis in solution and spectroelectrochemistry and molecular dynamic simulations of hSO on monolayer-modified gold electrodes. Moreover, for the first time a photoelectrochemical electrode involving immobilized hSO is demonstrated where photoexcitation of the CdS/hSO-modified electrode lead to an enhanced generation of bioelectrocatalytic currents upon sulfite addition. Oxidation starts already at the redox potential of the electron transfer domain of hSO and is greatly increased by application of a small overpotential to the CdS/hSO-modified ITO.

Pressure-Stabilized Tin Selenide Phase with an Unexpected Stoichiometry and a Predicted Superconducting State at Low Temperatures

NASA Astrophysics Data System (ADS)

Yu, Hulei; Lao, Wenxin; Wang, Lijuan; Li, Kuo; Chen, Yue

2017-03-01

Tin-selenium binary compounds are important semiconductors that have attracted much interest for thermoelectric and photovoltaic applications. As tin has a +2 or +4 oxidation state and selenium has an oxidation number of -2 , only SnSe and SnSe2 have been observed. In this work, we show that the chemical bonding between tin and selenium becomes counterintuitive under pressures. Combining evolutionary algorithms and density functional theory, a novel cubic tin-selenium compound with an unexpected stoichiometry 3 ∶4 has been predicted and further synthesized in laser-heated diamond anvil cell experiments. Different from the conventional SnSe and SnSe2 semiconductors, Sn3 Se4 is predicted to be metallic and exhibit a superconducting transition at low temperatures. Based on electron density and Bader charge analysis, we show that Sn3 Se4 has a mixed nature of chemical bonds. The successful synthesis of Sn3 Se4 paves the way for the discovery of other IV-VI compounds with nonconventional stoichiometries and novel properties.

Pressure-Stabilized Tin Selenide Phase with an Unexpected Stoichiometry and a Predicted Superconducting State at Low Temperatures.

PubMed

Yu, Hulei; Lao, Wenxin; Wang, Lijuan; Li, Kuo; Chen, Yue

2017-03-31

Tin-selenium binary compounds are important semiconductors that have attracted much interest for thermoelectric and photovoltaic applications. As tin has a +2 or +4 oxidation state and selenium has an oxidation number of -2, only SnSe and SnSe_{2} have been observed. In this work, we show that the chemical bonding between tin and selenium becomes counterintuitive under pressures. Combining evolutionary algorithms and density functional theory, a novel cubic tin-selenium compound with an unexpected stoichiometry 3∶4 has been predicted and further synthesized in laser-heated diamond anvil cell experiments. Different from the conventional SnSe and SnSe_{2} semiconductors, Sn_{3}Se_{4} is predicted to be metallic and exhibit a superconducting transition at low temperatures. Based on electron density and Bader charge analysis, we show that Sn_{3}Se_{4} has a mixed nature of chemical bonds. The successful synthesis of Sn_{3}Se_{4} paves the way for the discovery of other IV-VI compounds with nonconventional stoichiometries and novel properties.

Boron-Doped Nanocrystalline Diamond Electrodes for Neural Interfaces: In vivo Biocompatibility Evaluation

PubMed Central

Alcaide, María; Taylor, Andrew; Fjorback, Morten; Zachar, Vladimir; Pennisi, Cristian P.

2016-01-01

Boron-doped nanocrystalline diamond (BDD) electrodes have recently attracted attention as materials for neural electrodes due to their superior physical and electrochemical properties, however their biocompatibility remains largely unexplored. In this work, we aim to investigate the in vivo biocompatibility of BDD electrodes in relation to conventional titanium nitride (TiN) electrodes using a rat subcutaneous implantation model. High quality BDD films were synthesized on electrodes intended for use as an implantable neurostimulation device. After implantation for 2 and 4 weeks, tissue sections adjacent to the electrodes were obtained for histological analysis. Both types of implants were contained in a thin fibrous encapsulation layer, the thickness of which decreased with time. Although the level of neovascularization around the implants was similar, BDD electrodes elicited significantly thinner fibrous capsules and a milder inflammatory reaction at both time points. These results suggest that BDD films may constitute an appropriate material to support stable performance of implantable neural electrodes over time. PMID:27013949

Wear-triggered self-healing behavior on the surface of nanocrystalline nickel aluminum bronze/Ti3SiC2 composites

NASA Astrophysics Data System (ADS)

Zhai, Wenzheng; Lu, Wenlong; Zhang, Po; Wang, Jian; Liu, Xiaojun; Zhou, Liping

2018-04-01

Self-healing can protect materials from diverse damages, but is intrinsically difficult in metals. This paper demonstrates a potential method through a simultaneous decomposition and oxidation of Ti3SiC2 to achieve healing of stress cracking on the surface of nickel aluminum bronze (NAB)/Ti3SiC2 nanocrystalline composites during fretting wear. At the finest nanocrystalline materials, a crack recovery would be attained at 76.5%. The repetitive fretting wear leads to a modest amount of 'flowability' of Ti3SiC2 toward the crack, facilitating crack recovery. Along with the wear-triggered self-healing, the NAB/Ti3SiC2 shows an improved tribological performance with the stable decreased friction torque due to the formation of lubrication TiO2 oxide.

Precise identification and manipulation of adsorption geometry of donor-π-acceptor dye on nanocrystalline TiO₂ films for improved photovoltaics.

PubMed

Zhang, Fan; Ma, Wei; Jiao, Yang; Wang, Jingchuan; Shan, Xinyan; Li, Hui; Lu, Xinghua; Meng, Sheng

2014-12-24

Adsorption geometry of dye molecules on nanocrystalline TiO2 plays a central role in dye-sensitized solar cells, enabling effective sunlight absorption, fast electron injection, optimized interface band offsets, and stable photovoltaic performance. However, precise determination of dye binding geometry and proportion has been challenging due to complexity and sensitivity at interfaces. Here employing combined vibrational spectrometry and density functional calculations, we identify typical adsorption configurations of widely adopted cyanoacrylic donor-π bridge-acceptor dyes on nanocrystalline TiO2. Binding mode switching from bidentate bridging to hydrogen-bonded monodentate configuration with Ti-N bonding has been observed when dye-sensitizing solution becomes more basic. Raman and infrared spectroscopy measurements confirm this configuration switch and determine quantitatively the proportion of competing binding geometries, with vibration peaks assigned using density functional theory calculations. We further found that the proportion of dye-binding configurations can be manipulated by adjusting pH value of dye-sensitizing solutions. Controlling molecular adsorption density and configurations led to enhanced energy conversion efficiency from 2.4% to 6.1% for the fabricated dye-sensitized solar cells, providing a simple method to improve photovoltaic performance by suppressing unfavorable binding configurations in solar cell applications.

Direct synthesis and characterization of optically transparent conformal zinc oxide nanocrystalline thin films by rapid thermal plasma CVD

NASA Astrophysics Data System (ADS)

Pedersen, Joachim D.; Esposito, Heather J.; Teh, Kwok Siong

2011-10-01

We report a rapid, self-catalyzed, solid precursor-based thermal plasma chemical vapor deposition process for depositing a conformal, nonporous, and optically transparent nanocrystalline ZnO thin film at 130 Torr (0.17 atm). Pure solid zinc is inductively heated and melted, followed by ionization by thermal induction argon/oxygen plasma to produce conformal, nonporous nanocrystalline ZnO films at a growth rate of up to 50 nm/min on amorphous and crystalline substrates including Si (100), fused quartz, glass, muscovite, c- and a-plane sapphire (Al2O3), gold, titanium, and polyimide. X-ray diffraction indicates the grains of as-deposited ZnO to be highly textured, with the fastest growth occurring along the c-axis. The individual grains are observed to be faceted by (103) planes which are the slowest growth planes. ZnO nanocrystalline films of nominal thicknesses of 200 nm are deposited at substrate temperatures of 330°C and 160°C on metal/ceramic substrates and polymer substrates, respectively. In addition, 20-nm- and 200-nm-thick films are also deposited on quartz substrates for optical characterization. At optical spectra above 375 nm, the measured optical transmittance of a 200-nm-thick ZnO film is greater than 80%, while that of a 20-nm-thick film is close to 100%. For a 200-nm-thick ZnO film with an average grain size of 100 nm, a four-point probe measurement shows electrical conductivity of up to 910 S/m. Annealing of 200-nm-thick ZnO films in 300 sccm pure argon at temperatures ranging from 750°C to 950°C (at homologous temperatures between 0.46 and 0.54) alters the textures and morphologies of the thin film. Based on scanning electron microscope images, higher annealing temperatures appear to restructure the ZnO nanocrystalline films to form nanorods of ZnO due to a combination of grain boundary diffusion and bulk diffusion. PACS: films and coatings, 81.15.-z; nanocrystalline materials, 81.07.Bc; II-VI semiconductors, 81.05.Dz.

The Southeast Asian Tin Belt

NASA Astrophysics Data System (ADS)

Schwartz, M. O.; Rajah, S. S.; Askury, A. K.; Putthapiban, P.; Djaswadi, S.

1995-07-01

The Southeast Asian Tin Belt is a north-south elongate zone 2800 km long and 400 km wide, extending from Burma (Myanmar) and Thailand to Peninsular Malaysia and the Indonesian Tin Islands. Altogether 9.6 million tonnes of tin, equivalent to 54% of the world's tin production is derived from this region. Most of the granitoids in the region can be grouped geographically into elongate provinces or belts, based on petrographic and geochronological features. - The Main Range Granitoid Province in western Peninsular Malaysia, southern Peninsular Thailand and central Thailand is almost entirely made up of biotite granite (184-230 Ma). Tin deposits associated with these granites contributed 55% of the historic tin production of Southeast Asia. - The Northern Granitoid Province in northern Thailand (0.1% of tin production) also has dominant biotite granite (200-269 Ma) but it is distinguished by abundant post-intrusion deformation. - The Eastern Granitoid Province extends from eastern Peninsular Malaysia to eastern Thailand. The Malaysian part is subdivided into the East Coast Belt (220-263 Ma), Boundary Range Belt (197-257 Ma) and Central Belt (79-219 Ma). The granitoids cover a wide compositional range from biotite granite to hornblende-biotite granite/granodiorite and diorite-gabbro. Tin deposits are associated with biotite granite in the East Coast Belt (3% of tin production). The granitoids in the other areas of the Eastern Granitoid Province are barren. - The Western Granitoid Province (22-149 Ma) in northern Peninsular Thailand, western Thailand and Burma has biotite granite and hornblende-biotite granite/granodiorite. Tin deposits are associated with biotite granite, which probably is the dominant phase (14% of tin production). The granitoids of the Indonesian Tin Islands (193-251 Ma) do not permit grouping into geographically distinct units. Main Range-type and Eastern Province-type plutons occur next to each other. Most of the tin deposits are associated with Main

Four-probe electrical-transport measurements on single indium tin oxide nanowires between 1.5 and 300 K

NASA Astrophysics Data System (ADS)

Chiu, Shao-Pin; Chung, Hui-Fang; Lin, Yong-Han; Kai, Ji-Jung; Chen, Fu-Rong; Lin, Juhn-Jong

2009-03-01

Single-crystalline indium tin oxide (ITO) nanowires (NWs) were grown by the standard thermal evaporation method. The as-grown NWs were typically 100-300 nm in diameter and a few µm long. Four-probe submicron Ti/Au electrodes on individual NWs were fabricated by the electron-beam lithography technique. The resistivities of several single NWs have been measured from 300 down to 1.5 K. The results indicate that the as-grown ITO NWs are metallic, but disordered. The overall temperature behavior of resistivity can be described by the Bloch-Grüneisen law plus a low-temperature correction due to the scattering of electrons off dynamic point defects. This observation suggests the existence of numerous dynamic point defects in as-grown ITO NWs.

Simultaneous dynamic optical and electrical properties of endothelial cell attachment on indium tin oxide bioelectrodes.

PubMed

Choi, Chang K; English, Anthony E; Kihm, Kenneth D; Margraves, Charles H

2007-01-01

This study quantifies the dynamic attachment and spreading of porcine pulmonary artery endothelial cells (PPAECs) on optically thin, indium tin oxide (ITO) biosensors using simultaneous differential interference contrast microscopy (DICM) and electrical microimpedance spectroscopy. A lock-in amplifier circuit monitored the impedance of PPAECs cultivated on the transparent ITO bioelectrodes as a function of frequency between 10 Hz and 100 kHz and as a function of time, while DICM images were simultaneously acquired. A digital image processing algorithm quantified the cell-covered electrode area as a function of time. The results of this study show that the fraction of the cell-covered electrode area is in qualitative agreement with the electrical impedance during the attachment phase following the cell settling on the electrode surface. The possibility of several distinctly different states of electrode coverage and cellular attachment giving rise to similar impedance signals is discussed.

Synthesis, characterization, and photocatalytic properties of nanocrystalline NZO thin films

NASA Astrophysics Data System (ADS)

Aryanto, D.; Hastuti, E.; Husniya, N.; Sudiro, T.; Nuryadin, B. W.

2018-03-01

Nanocrystalline Ni-doped ZnO (NZO) thin films were synthesized on glass substrate using sol-gel spin coating methods. The effect of annealing on the structural and optical properties of nanocrystalline thin film was studied using X-ray diffractometer (XRD), field emission scanning electron microscopy (FESEM), UV-VIS spectrophotometry, and photoluminescence (PL). The results showed that the annealing temperature strongly influenced the physical properties of nanocrystalline NZO thin films. The photocatalytic properties of nanocrystalline NZO thin films were evaluated using an aqueous solution of Rhodamine-B. The photocatalytic activity of nanocrystalline NZO thin films increased with the increase of annealing temperature. The results indicated that the structure, morphology, and band gap energy of nanocrystalline NZO thin films played an important role in photocatalytic activity.

Thermal Studies of New Precursors to Indium-tin Oxides for Use as Sensor Materials in the Detection of NO(x)

NASA Technical Reports Server (NTRS)

Goldsby, J. C.; Kacik, T.; Hockensmith, C. M.

1999-01-01

Control of combustion product emissions in both sub and super-sonic jet engines can be facilitated by measurement of NO(x) levels with metal oxide sensors, In2O3, metal-doped SnO2, and SnO, (as well as other materials) show resistivity changes in the presence of NO(x), but often their sensitivity, stability, and selectivity are low. This study was designed to develop new synthetic pathways to precursors that produce high purity, two phase In2O3-SnO2. The precursors were formed by complexation of tin with any oxide ligands to give the ammonium salt (NH4). Thermal studies of these precursors were carried out by thermal gravimetry (TG) and differential scanning calorimetry (DSC). Further studies by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (NMR) were also conducted.

Ni-doped (CeO2- δ )-YSZ mesoarchitectured with nanocrystalline framework: the effect of thermal treatment on structure, surface chemistry and catalytic properties in the partial oxidation of methane (CPOM)

NASA Astrophysics Data System (ADS)

Somacescu, Simona; Florea, Mihaela; Osiceanu, Petre; Calderon-Moreno, Jose Maria; Ghica, Corneliu; Serra, Jose Manuel

2015-11-01

Ni-doped (CeO2- δ )-YSZ (5 mol% Ni oxide, 10 mol% ceria) mesoarchitectures (MA) with nanocrystalline framework have been synthesized by an original, facile and cheap approach based on Triton X100 nonionic surfactant as template and water as solvent at a strong basic pH value. Following the hydrothermal treatment under autogenous pressure ( 18 bars), Ni, Ce, Y, and Zr were well ordered as MA with nanocrystalline framework, assuring thermal stability. A comprehensive investigation of structure, texture, morphology, and surface chemistry was performed by means of a variety of complementary techniques (X-Ray Diffraction, XRD; Raman Spectroscopy, RS; Brunauer—Emmett—Teller, BET; Temperature—Programmed Reduction, TPR; Transmission Electron Microscopy, TEM and DF-STEM; X-ray Photoelectron Spectroscopy, XPS; Catalytic activity and selectivity). N2 sorption measurements highlighted that the mesoporous structure is formed at 600 °C and remains stable at 800 °C. At 900 °C, the MA collapses, favoring the formation of macropores. The XRD and Raman Spectroscopy of all samples showed the presence of a pure, single phase with fluorite-type structure. At 900 °C, an increased tetragonal distortion of the cubic lattice was observed. The surface chemistry probed by XPS exhibits a mixture of oxidation states (Ce3+ + Ce4+) with high percentage of Ce3+ valence state 35 % and (Ni3+ and Ni2+) oxidation states induced by the thermal treatment. These nanoparticles assembled into MA show high stability and selectivity over time in catalytic partial oxidation of methane (CPOM). These promising performances suggest an interesting prospect for introduction as anode within IT-SOFC assemblies.

Structure-Property Relationship of Phenylene-Based Self-Assembled-Monolayers for Record Low Work Function of Indium Tin Oxide.

PubMed

Benneckendorf, Frank S; Hillebrandt, Sabina; Ullrich, Florian; Rohnacher, Valentina; Hietzschold, Sebastian; Jänsch, Daniel; Freudenberg, Jan; Beck, Sebastian; Mankel, Eric; Jaegermann, Wolfram; Pucci, Annemarie; Bunz, Uwe H F; Müllen, Klaus

2018-06-20

Studying the structure-property relations of tailored dipolar phenyl and biphenylphosphonic acids we report self-assembled monolayers with a significant decrease of the work function (WF) of indium-tin oxide (ITO) electrodes. While the strengths of the dipoles are varied through the different molecular lengths and the introduction of electron-withdrawing fluorine atoms, the surface energy is kept constant through the electron-donating N,N dimethylamine head groups. The self-assembled monolayer formation and its modification of the electrodes are investigated via infrared reflection absorption spectroscopy, contact angle measurements, and photoelectron spectroscopy. The WF decrease of ITO correlates with increasing molecular dipoles. The lowest ever recorded WF of 3.7 eV is achieved with the fluorinated biphenylphosphonic acid.

Indium tin oxide films prepared by atmospheric plasma annealing and their semiconductor-metal conductivity transition around room temperature

NASA Astrophysics Data System (ADS)

Li, Yali; Li, Chunyang; He, Deyan; Li, Junshuai

2009-05-01

We report the synthesis of indium tin oxide (ITO) films using the atmospheric plasma annealing (APA) technique combined with the spin-coating method. The ITO film with a low resistivity of ~4.6 × 10-4 Ω cm and a high visible light transmittance, above 85%, was achieved. Hall measurement indicates that compared with the optimized ITO films deposited by magnetron sputtering, the above-mentioned ITO film has a higher carrier concentration of ~1.21 × 1021 cm-3 and a lower mobility of ~11.4 cm2 V-1 s-1. More interestingly, these electrical characteristics result in the semiconductor-metal conductivity transition around room temperature for the ITO films prepared by APA.

Tin whiskers in electronic circuits

NASA Astrophysics Data System (ADS)

Stupian, Gary W.

1992-12-01

Fibrous, conducting 'whiskers' often grow on pure tin plating. These tin whiskers have, for many years, been known to pose a reliability problem in electronic circuitry; therefore, the use of pure tin coatings in any critical electronic application is not recommended. Despite the warnings of the experts, tin plating is still found on electronic and mechanical components and problems with whiskers still arise. This document summarizes what is known about the growth of tin whiskers. A number of factors (e.g., coating thickness, plating conditions) are thought to be important in determining whether whiskers will grow. Although tin whiskers have been investigated from some decades, there is still disagreement on the effects of virtually every coating parameter. There is no disagreement, however, on the essential fact that it is very difficult to predict with certainty whether whiskers will grow on any specific tin-plated component, which of course is the basis of the 'experts' advice not to use pure tin plating. If tin-plated components are found in an electronic system, replacement is the safest policy. Some additional recommendations to minimize risk are presented here that may be of use in situations in which replacement of all suspect components is not the option of choice because of cost or schedule constraints.

Growth, intermixing, and surface phase formation for zinc tin oxide nanolaminates produced by atomic layer deposition

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

Hägglund, Carl, E-mail: carl.hagglund@angstrom.uu.se; Grehl, Thomas; Brongersma, Hidde H.

2016-03-15

A broad and expanding range of materials can be produced by atomic layer deposition at relatively low temperatures, including both oxides and metals. For many applications of interest, however, it is desirable to grow more tailored and complex materials such as semiconductors with a certain doping, mixed oxides, and metallic alloys. How well such mixed materials can be accomplished with atomic layer deposition requires knowledge of the conditions under which the resulting films will be mixed, solid solutions, or laminated. The growth and lamination of zinc oxide and tin oxide is studied here by means of the extremely surface sensitivemore » technique of low energy ion scattering, combined with bulk composition and thickness determination, and x-ray diffraction. At the low temperatures used for deposition (150 °C), there is little evidence for atomic scale mixing even with the smallest possible bilayer period, and instead a morphology with small ZnO inclusions in a SnO{sub x} matrix is deduced. Postannealing of such laminates above 400 °C however produces a stable surface phase with a 30% increased density. From the surface stoichiometry, this is likely the inverted spinel of zinc stannate, Zn{sub 2}SnO{sub 4}. Annealing to 800 °C results in films containing crystalline Zn{sub 2}SnO{sub 4}, or multilayered films of crystalline ZnO, Zn{sub 2}SnO{sub 4}, and SnO{sub 2} phases, depending on the bilayer period.« less

Synthesis of organically templated nanoporous tin (II/IV) phosphate for radionuclide and metal sequestration

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

Wellman, Dawn M.; Mattigod, Shas V.; Parker, Kent E.

2006-03-20

Nanoporous tin (II/IV) phosphate materials, with spherical morphology, have been synthesized using cetyltrimethylammonium chloride (CH3(CH2)15N(CH3)3Cl) as the surfactant. The structure of the material is stable at 500°C; however, partial oxidation of the material occurs with redox conversion of Sn2+ to Sn4+, resulting in a mixed Sn(II)/ Sn(IV) material. Preliminary batch contact studies were conducted to assess the effectiveness of nanoporous tin phosphate, NP-SnPO, in sequestering redox sensitive metals and radionuclides, technetium(VII), neptunium(V), thorium(IV), and a toxic metal, chromium(VI), from aqueous matrices. Results indicate tin (II) phosphate removed > 95% of all contaminants investigated from solution.

Comparative assessment of gastrointestinal irritant potency in man of tin(II) chloride and tin migrated from packaging.

PubMed

Boogaard, Peter J; Boisset, Michel; Blunden, Steve; Davies, Scot; Ong, Teng Jin; Taverne, Jean-Pierre

2003-12-01

Tin is present in low concentrations in most canned foods and beverages, the highest levels being found in products packaged in unlacquered or partially lacquered tinplate cans. A limited number of case-reports of acute gastrointestinal disorders after consumption of food containing 100-500 mg/kg tin have been reported, but these reports suffer many insufficiencies. Controlled clinical studies on acute effects of tin migrated from packaging suggest a threshold concentration for adverse effects (AEs) of >730 mg/kg. Two separate randomised, single-centre, double-blind, crossover studies, enabling comparison of the tolerability of tin added as tin(II) chloride at concentrations of <0.5, 161, 264 and 529 mg/kg in 250 ml tomato juice in 20 volunteers (Study 1) and tin migrated from packaging at concentrations of <0.5, 201 and 267 mg/kg in 250 ml tomato soup in 24 volunteers (Study 2) were carried out. Distribution studies were conducted to get insight in the acute AEs of low molecular weight (<1000 Da) tin species in the soluble fraction of food products. Results show that the chemical form of tin and not the elemental concentration per se determines the severity of AEs. A clear dose-response relationship was only observed when tin was added as tin(II) chloride in tomato juice. No clinically significant AEs were reported in Study 2 and comparison of the incidence of tin-related AEs showed no difference between the dose levels (including control). Tin species of low molecular weight in supernatant represented 31-32% of total tin in canned tomato soup versus 56-61% in juice freshly spiked with tin(II) chloride. Differences in the incidence of AEs following administration of tomato juice with 161 and 264 mg of tin per kg and tomato soup with 201 and 267 mg of tin per kg likely results from differences in the concentration of low molecular weight tin species and in the nature of tin complexes formed. The results of this work demonstrate that tin levels up to 267 mg/kg in

Simultaneous determination of epinephrene and paracetamol at copper-cobalt oxide spinel decorated nanocrystalline zeolite modified electrodes.

PubMed

Samanta, Subhajyoti; Srivastava, Rajendra

2016-08-01

In this study, CuCo2O4 and CuCo2O4 decorated nanocrystalline ZSM-5 materials were prepared. For comparative study, a series of MCo2O4 spinels were also prepared. Materials were characterized by the complementary combination of X-ray diffraction, N2-adsorption, UV-visible, and electron microscopic techniques. A simple and rapid method for the simultaneous determination of paracetamol and epinephrine at MCo2O4 spinels modified electrodes is presented in this manuscript. Among the materials investigated in this study, CuCo2O4 decorated nanocrystalline ZSM-5 exhibited the highest electrocatalytic activity with excellent stability, sensitivity, and selectivity. Analytical performance of the sensor was demonstrated in the determination of epinephrine and paracetamol in the commercial pharmaceutical samples. Copyright © 2016 Elsevier Inc. All rights reserved.

Direct transparent electrode patterning on layered GaN substrate by screen printing of indium tin oxide nanoparticle ink for Eu-doped GaN red light-emitting diode

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

Kashiwagi, Y., E-mail: kasiwagi@omtri.or.jp; Yamamoto, M.; Saitoh, M.

2014-12-01

Transparent electrodes were formed on Eu-doped GaN-based red-light-emitting diode (GaN:Eu LED) substrates by the screen printing of indium tin oxide nanoparticle (ITO np) inks as a wet process. The ITO nps with a mean diameter of 25 nm were synthesized by the controlled thermolysis of a mixture of indium complexes and tin complexes. After the direct screen printing of ITO np inks on GaN:Eu LED substrates and sintering at 850 °C for 10 min under atmospheric conditions, the resistivity of the ITO film was 5.2 mΩ cm. The fabricated LED up to 3 mm square surface emitted red light when the on-voltage was exceeded.

Electroreduction-based electrochemical-enzymatic redox cycling for the detection of cancer antigen 15-3 using graphene oxide-modified indium-tin oxide electrodes.

PubMed

Park, Seonhwa; Singh, Amardeep; Kim, Sinyoung; Yang, Haesik

2014-02-04

We compare herein biosensing performance of two electroreduction-based electrochemical-enzymatic (EN) redox-cycling schemes [the redox cycling combined with simultaneous enzymatic amplification (one-enzyme scheme) and the redox cycling combined with preceding enzymatic amplification (two-enzyme scheme)]. To minimize unwanted side reactions in the two-enzyme scheme, β-galactosidase (Gal) and tyrosinase (Tyr) are selected as an enzyme label and a redox enzyme, respectively, and Tyr is selected as a redox enzyme label in the one-enzyme scheme. The signal amplification in the one-enzyme scheme consists of (i) enzymatic oxidation of catechol into o-benzoquinone by Tyr and (ii) electroreduction-based EN redox cycling of o-benzoquinone. The signal amplification in the two-enzyme scheme consists of (i) enzymatic conversion of phenyl β-d-galactopyranoside into phenol by Gal, (ii) enzymatic oxidation of phenol into catechol by Tyr, and (iii) electroreduction-based EN redox cycling of o-benzoquinone including further enzymatic oxidation of catechol to o-benzoquinone by Tyr. Graphene oxide-modified indium-tin oxide (GO/ITO) electrodes, simply prepared by immersing ITO electrodes in a GO-dispersed aqueous solution, are used to obtain better electrocatalytic activities toward o-benzoquinone reduction than bare ITO electrodes. The detection limits for mouse IgG, measured with GO/ITO electrodes, are lower than when measured with bare ITO electrodes. Importantly, the detection of mouse IgG using the two-enzyme scheme allows lower detection limits than that using the one-enzyme scheme, because the former gives higher signal levels at low target concentrations although the former gives lower signal levels at high concentrations. The detection limit for cancer antigen (CA) 15-3, a biomarker of breast cancer, measured using the two-enzyme scheme and GO/ITO electrodes is ca. 0.1 U/mL, indicating that the immunosensor is highly sensitive.

Corn-like indium tin oxide nanostructures: fabrication, characterization and formation mechanism

NASA Astrophysics Data System (ADS)

Wu, Xu; Wang, Yihua; Yang, Bin

2015-11-01

Electrospinning is a simple but efficient procedure enabling the parallel fabrication of a multitude of inorganic fibers. But the precise control of the fiber's morphology, which seriously affects the electrical, optical and other important properties of such electrospun materials, is still less developed. The creation of nanoscale indium tin oxide fibers with corn-like geometry (corn-like ITO NFs) by our group has provided a good example to show how to modify the morphologies and properties of nanofibers by means of tailoring the fiber's compositions. Here we show that in the fabrication of corn-like ITO NFs, the usage of different solvents N, N-dimethylformamide (DMF) and deionized water, as well as the calcination temperature, can also lead to dramatic morphology changes, from ribbon-like to cylindrical and then to corn-like. The resultant nanoribbons and nanoscale corn-like fibers exhibit different photoluminescence properties. We find that the morphology of the as-spun fibers is closely related to the vapor pressure of the solvent we used, and the generation of ITO crystals sensitively depends on the calcination temperature, which both are critical for the morphology and properties of the final products. Thus, we demonstrate that the formation of this unprecedented nanostructure is determined by the combined effect of the precursor chemical composition, solvent and calcination temperature.

Plasma-enhanced atomic layer deposition for plasmonic TiN

NASA Astrophysics Data System (ADS)

Otto, Lauren M.; Hammack, Aaron T.; Aloni, Shaul; Ogletree, D. Frank; Olynick, Deirdre L.; Dhuey, Scott; Stadler, Bethanie J. H.; Schwartzberg, Adam M.

2016-09-01

This work presents the low temperature plasma-enhanced atomic layer deposition (PE-ALD) of TiN, a promising plasmonic synthetic metal. The plasmonics community has immediate needs for alternatives to traditional plasmonic materials (e.g. Ag and Au), which lack chemical, thermal, and mechanical stability. Plasmonic alloys and synthetic metals have significantly improved stability, but their growth can require high-temperatures (>400 °C), and it is difficult to control the thickness and directionality of the resulting film, especially on technologically important substrates. Such issues prevent the application of alternative plasmonic materials for both fundamental studies and large-scale industrial applications. Alternatively, PE-ALD allows for conformal deposition on a variety of substrates with consistent material properties. This conformal coating will allow the creation of exotic three-dimensional structures, and low-temperature deposition techniques will provide unrestricted usage across a variety of platforms. The characterization of this new plasmonic material was performed with in-situ spectroscopic ellipsometry as well as Auger electron spectroscopy for analysis of TiN film sensitivity to oxide cross-contamination. Plasmonic TiN films were fabricated, and a chlorine plasma etch was found to pattern two dimensional gratings as a test structure. Optical measurements of 900 nm period gratings showed reasonable agreement with theoretical modeling of the fabricated structures, indicating that ellipsometry models of the TiN were indeed accurate.

Palladium-tin catalysts for the direct synthesis of H 2O 2 with high selectivity

DOE PAGES

Freakley, Simon J.; He, Qian; Harrhy, Jonathan H.; ...

2016-02-25

The direct synthesis of hydrogen peroxide (H 2O 2 ) from H 2 and O 2 represents a potentially atom-efficient alternative to the current industrial indirect process. We show that the addition of tin to palladium catalysts coupled with an appropriate heat treatment cycle switches off the sequential hydrogenation and decomposition reactions, enabling selectivities of >95% toward H 2O 2 . This effect arises from a tin oxide surface layer that encapsulates small Pd-rich particles while leaving larger Pd-Sn alloy particles exposed. In conclusion, we show that this effect is a general feature for oxide-supported Pd catalysts containing an appropriatemore » second metal oxide component, and we set out the design principles for producing high-selectivity Pd-based catalysts for direct H 2O 2 production that do not contain gold.« less

Determination of total tin in silicate rocks by graphite furnace atomic absorption spectrometry

USGS Publications Warehouse

Elsheimer, H.N.; Fries, T.L.

1990-01-01

A method is described for the determination of total tin in silicate rocks utilizing a graphite furnace atomic absorption spectrometer with a stabilized-temperature platform furnace and Zeeman-effect background correction. The sample is decomposed by lithium metaborate fusion (3 + 1) in graphite crucibles with the melt being dissolved in 7.5% hydrochloric acid. Tin extractions (4 + 1 or 8 + 1) are executed on portions of the acid solutions using a 4% solution of tricotylphosphine oxide in methyl isobutyl ketone (MIBK). Ascorbic acid is added as a reducing agent prior to extraction. A solution of diammonium hydrogenphosphate and magnesium nitrate is used as a matrix modifier in the graphite furnace determination. The limit of detection is > 10 pg, equivalent to > 1 ??g l-1 of tin in the MIBK solution or 0.2-0.3 ??g g-61 in the rock. The concentration range is linear between 2.5 and 500 ??g l-1 tin in solution. The precision, measured as relative standard deviation, is < 20% at the 2.5 ??g l-1 level and < 7% at the 10-30 ??g l-1 level of tin. Excellent agreement with recommended literature values was found when the method was applied to the international silicate rock standards BCR-1, PCC-1, GSP-1, AGV-1, STM-1, JGb-1 and Mica-Fe. Application was made to the determination of tin in geological core samples with total tin concentrations of the order of 1 ??g g-1 or less.

Oxidized nanocrystalline Fe-Cu pseudoalloy subjected to high pressure and electrodischarge pulses: Mössbauer and x-ray investigations

NASA Astrophysics Data System (ADS)

Gavriliuk, A. G.; Voitkovsky, V. S.; Sidorov, V. A.; Filonenko, V. P.; Tsiok, O. B.; Khvostantsev, L. G.

1998-05-01

Nanocrystalline Fe15Cu85 pseudoalloy has been subjected to pulsed heating up to 1500 K at high pressure (8 GPa). Two regimes were studied: the direct heating using electrodischarge through the sample and indirect heating with the use of cylindrical heater around the sample. The temperature and time conditions in both types of experiments were adjusted to be equivalent. The discharge parameters (stored energy, discharge time, and magnitude of current pulse) were sufficient to move defects by conduction electrons, but insufficient to melt the sample. The properties of treated samples were studied using Mössbauer absorption spectra and x-ray diffraction for three types of samples: (a) primary powder treated by high pressure up to 8 GPa, (b) powder subjected to indirect pulsed heating at 8 GPa, (c) powder treated by electrical pulses at 8 GPa. The x-ray diffraction pattern of primary powder exhibits peaks of copper, iron, and copper oxide (CuO). The Mössbauer spectrum of primary powder exhibits six peaks of alpha iron and some peaks near zero velocity due to the small iron clusters in the copper matrix and ultrafine clusters of paramagnetic phase x-Fe2O3. The transformation of CuO to Cu2O takes place in the course of indirect heating, the Mössbauer spectrum being almost unchanged. The direct electrodischarge heating causes the appearance of new magnetic phase with the magnetic field on iron nucleus 505 kOe, which corresponds to α-Fe2O3. The formation of α-Fe2O3 was confirmed by x-ray diffraction. At the same time the transformation of CuO to Cu2O is incomplete. These experiments demonstrate that high density current pulses, causing the electron wind, can be a useful tool to influence the structure of nanocrystalline powder.

Catalyst for Oxidation of Volatile Organic Compounds

NASA Technical Reports Server (NTRS)

Wood, George M. (Inventor); Upchurch, Billy T. (Inventor); Schryer, David R. (Inventor); Davis, Patricia P. (Inventor); Kielin, Erik J. (Inventor); Brown, Kenneth G. (Inventor); Schyryer, Jacqueline L. (Inventor); DAmbrosia, Christine M. (Inventor)

2000-01-01

Disclosed is a process for oxidizing volatile organic compounds to carbon dioxide and water with the minimal addition of energy. A mixture of the volatile organic compound and an oxidizing agent (e.g. ambient air containing the volatile organic compound) is exposed to a catalyst which includes a noble metal dispersed on a metal oxide which possesses more than one oxidation state. Especially good results are obtained when the noble metal is platinum, and the metal oxide which possesses more than one oxidation state is tin oxide. A promoter (i.e., a small amount of an oxide of a transition series metal) may be used in association with the tin oxide to provide very beneficial results.

Electrical properties of thin film transistors with zinc tin oxide channel layer

NASA Astrophysics Data System (ADS)

Hong, Seunghwan; Oh, Gyujin; Kim, Eun Kyu

2017-10-01

We have investigated thin film transistors (TFTs) with zinc tin oxide (ZTO) channel layer fabricated by using an ultra-high vacuum radio frequency sputter. ZTO thin films were grown at room temperature by co-sputtering of ZnO and SnO2, which applied power for SnO2 target was varied from 15 W to 90 W under a fixed sputtering power of 70 W for ZnO target. A post-annealing treatment to improve the film quality was done at temperature ranges from 300 to 600 °C by using the electrical furnace. The ZTO thin films showed good electrical and optical properties such as Hall mobility of more than 9 cm2/V·s, specific resistivity of about 2 × 102 Ω·cm, and optical transmittance of 85% in visible light region by optical bandgap of 3.3 eV. The ZTO-TFT with an excellent performance of channel mobility of 19.1 cm2/V·s and on-off ratio ( I on / I off ) of 104 was obtained from the films grown with SnO2 target power of 25 W and post-annealed at 450 °C. This result showed that ZTO film is promising on application to a high performance transparent TFTs.

Effects of Concentration of Nanoscale Tin-Doped Indium Oxide on Electrical Breakdown of High-Resistance Liquid Crystal

NASA Astrophysics Data System (ADS)

Liang, Bau-Jy; Liu, Don-Gey; Chang, Chih-Yuan; Shie, Wun-Yi

2011-05-01

According to our previous study, a high concentration of nanoscale tin-doped indium oxide (ITO) may be beneficial for protecting liquid crystal (LC) against attacks by electrostatic discharge (ESD). In this study, the influence of high-voltage stresses in an ESD test was investigated for cells doped with different concentrations of ITO. It was found that nano-ITO with a concentration of 0.4% in weight ratio deteriorated the physical properties of LC of transparency transition and charge retention. However, our experiment showed that the capability of ESD protection for the doped LC was still improved at the ITO concentration of 0.4 wt %. This finding supports the proposed model in our previous report. The role of ITO in the LC is not always beneficial, as discussed in this paper.

Optical and Electrical Properties of Tin-Doped Cadmium Oxide Films Prepared by Electron Beam Technique

NASA Astrophysics Data System (ADS)

Ali, H. M.; Mohamed, H. A.; Wakkad, M. M.; Hasaneen, M. F.

2009-04-01

Tin-doped cadmium oxide films were deposited by electron beam evaporation technique. The structural, optical and electrical properties of the films were characterized. The X-ray diffraction (XRD) study reveals that the films are polycrystalline in nature. As composition and structure change due to the dopant ratio and annealing temperature, the carrier concentration was varied around 1020 cm-3, and the mobility increased from less than 10 to 45 cm2 V-1 s-1. A transmittance value of ˜83% and a resistivity value of 4.4 ×10-4 Ω cm were achieved for (CdO)0.88(SnO2)0.12 film annealed at 350 °C for 15 min., whereas the maximum value of transmittance ˜93% and a resistivity value of 2.4 ×10-3 Ω cm were obtained at 350 °C for 30 min. The films exhibited direct band-to-band transitions, which corresponded to optical band gaps of 3.1-3.3 eV.

Dark solitons in erbium-doped fiber lasers based on indium tin oxide as saturable absorbers

NASA Astrophysics Data System (ADS)

Guo, Jia; Zhang, Huanian; Li, Zhen; Sheng, Yingqiang; Guo, Quanxin; Han, Xile; Liu, Yanjun; Man, Baoyuan; Ning, Tingyin; Jiang, Shouzhen

2018-04-01

Dark solitons, which have good stability, long transmission distance and strong anti-interference ability. By using a coprecipitation method, the high quality indium tin oxide (ITO) were prepared with an average diameter of 34.1 nm. We used a typical Z-scan scheme involving a balanced twin-detector measurement system to investigated nonlinear optical properties of the ITO nanoparticles. The saturation intensity and modulation depths are 13.21 MW/cm2 and 0.48%, respectively. In an erbium-doped fiber (EDF) lasers, we using the ITO nanoparticles as saturable absorber (SA), and the formation of dark soliton is experimentally demonstrated. The generated dark solitons are centered at the wavelength of 1561.1 nm with a repetition rate of 22.06 MHz. Besides, the pulse width and pulse-to-pulse interval of the dark solitons is ∼1.33ns and 45.11 ns, respectively. These results indicate that the ITO nanoparticles is a promising nanomaterial for ultrafast photonics.

The Bulk Nanocrystalline zn Produced by Mechanical Attrition

NASA Astrophysics Data System (ADS)

Zhu, X. K.; Zhao, K. Y.; Li, C. J.; Tao, J. M.; Chan, T. L.; Koch, C. C.

The purpose of experiment was to produce bulk nanocrystalline Zn by mechanical attrition. The bulk nanocrystalline Zn produced by mechanical attrition was studied. The microstructural evolution during cryomilling and subsequent room temperature milling was characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). In this paper, Nanocrystalline Zn was produced by insitu consolidation of Zn elemental powder using mechanical attrition at liquid nitrogen and room temperature. For the samples studied, the longest elongation of 65% and highest stress of 200 MPa is obtained in nanocrystalline Zn during tensile testing at the condition of strain rate (10-3 sec-1) and 20°C which is equal to 0.43 Tm (Tm is the melting temperature of pure Zn).

Investigating the Thermal and Phase Stability of Nanocrystalline Ni-W Produced by Electrodeposition, Sputtering, and Mechanical Alloying

NASA Astrophysics Data System (ADS)

Marvel, Christopher Jonathan

diffusivity calculations conceptually suggested that increasing W alloying concentrations can decrease the grain growth rate. The strongest evidence of grain growth stagnation was via nanoscale oxide particle drag in highly contaminated electrodeposited alloys. Interestingly, W-segregation was also detected to the oxide phase boundaries and revealed a potential indirect mechanism of thermal stability. The phase stability of pure and contaminated Ni-W alloys was investigated with density functional theory. Primarily, the calculations suggested that the intermetallic phases NiW and NiW2 are thermodynamically unstable, meaning the binary phase diagram is incorrect, but the ternary carbides Ni 6W6C and Ni2W4C are stable. Several Ni-W binary and Ni-W-C ternary phase diagrams were constructed using a simplified CALPHAD approach to improve the understanding of Ni-W phase stability. Lastly, it was determined that the fabrication process greatly influences the impurity types and concentrations of the alloys, and therefore greatly dictate which thermal stability mechanisms are active. Mechanically alloyed samples were found to be the most resistant to grain growth. The findings of this research will hopefully guide future efforts to design more thermally stable nanocrystalline alloys. The link between phase stability and grain growth behavior of Ni-W was thoroughly discussed, as well as the dependence of bulk fabrication processing on the contamination found in the alloys. Ultimately, this research has greatly expanded the general understanding of nanocrystalline Ni-W microstructures, and it is likely that similar phenomena occur in other nanocrystalline systems.

Recovery of tin from metal powders of waste printed circuit boards.

PubMed

Yang, Tianzu; Zhu, Pengchun; Liu, Weifeng; Chen, Lin; Zhang, Duchao

2017-10-01

To avoid the adverse effects of tin on the smelting process used to recover copper from metal powders of waste printed circuit boards, an effective process is proposed that selectively extracts tin and its associated metals. That impacts of alkaline pressure oxidation leaching parameters on metal conversion were systematically investigated. The results showed that Sn, Pb, Al and small amounts of Zn in the metal powders were leached out, leaving copper residue. By optimizing the conditions, leaching recovery of 98.2%, 77.6%, 78.3 and 6.8% for Sn, Pb, Al and Zn, respectively, were achieved. Subsequently, more than 99.9% of Pb and Zn in the leaching solution were removed as a mixture of PbS-ZnS in the purification process, which can be used as a raw material in Pb smelting. Approximately 86.2% of Sn in the purified solution was recovered by electrowinning, and the purity of the cathode tin was over 99.8%. Copyright © 2017 Elsevier Ltd. All rights reserved.

Facile synthesis of antimony-doped tin oxide nanoparticles by a polymer-pyrolysis method

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

Li, Yuan-Qing, E-mail: yqli@mail.ipc.ac.cn; Wang, Jian-Lei; Fu, Shao-Yun, E-mail: syfu@mail.ipc.ac.cn

2010-06-15

In this article, antimony-doped tin oxide (ATO) nanoparticles was synthesized by a facile polymer-pyrolysis method. The pyrolysis behaviors of the polymer precursors prepared via in situ polymerization of metal salts and acrylic acid were analyzed by simultaneous thermogravimetric and differential scanning calorimetry (TG-DSC). The structural and morphological characteristics of the products were studied by powder X-ray diffraction (XRD) and transmission electron microscope (TEM). The results reveal that the ATO nanoparticles calcined at 600 {sup o}C show good crystallinity with the cassiterite structure and cubic-spherical like morphology. The average particle size of ATO decreases from 200 to 15 nm as themore » Sb doping content increases from 5 mol% to 15 mol%. Electrical resistivity measurement shows that the resistivity for the 10-13 mol% Sb-doped SnO{sub 2} nanoparticles is reduced by more than three orders compared with the pure SnO{sub 2} nanoparticles. In addition, due to its versatility this polymer-pyrolysis method can be extended to facile synthesis of other doped n-type semiconductor, such as In, Ga, Al doped ZnO, Sn doped In{sub 2}O{sub 3}.« less

Anti-reflective coating with a conductive indium tin oxide layer on flexible glass substrates.

PubMed

Sung, Yilin; Malay, Robert E; Wen, Xin; Bezama, Christian N; Soman, Varun V; Huang, Ming-Huang; Garner, Sean M; Poliks, Mark D; Klotzkin, David

2018-03-20

Flexible glass has many applications including photovoltaics, organic light-emitting device (OLED) lighting, and displays. Its ability to be processed in a roll-to-roll facility enables high-throughput continuous manufacturing compared to conventional glass processing. For photovoltaic, OLED lighting, and display applications, transparent conductors are required with minimal optical reflection losses. Here, we demonstrate an anti-reflective coating (ARC) that incorporates a useful transparent conductor that is realizable on flexible substrates. This reduces the average reflectivity to less than 6% over the visible band from normal incidence to incident angles up to 60°. This ARC is designed by the average uniform algorithm method. The coating materials consist of a multilayer stack of an electrically functional conductive indium tin oxide with conductivity 2.95×10 5   Siemens/m (31 Ω/□), and AlSiO 2 . The coatings showed modest changes in reflectivity and no delamination after 10,000 bending cycles. This demonstrates that effective conductive layers can be integrated into ARCs and can be realized on flexible glass substrates with proper design and process control.

Defect-induced instability mechanisms of sputtered amorphous indium tin zinc oxide thin-film transistors

NASA Astrophysics Data System (ADS)

Park, Jinhee; Rim, You Seung; Li, Chao; Wu, Jiechen; Goorsky, Mark; Streit, Dwight

2018-04-01

We report the device performance and stability of sputtered amorphous indium-tin-zinc-oxide (ITZO) thin-film transistors as a function of oxygen ratio [O2/(Ar + O2)] during growth. Increasing the oxygen ratio enhanced the incorporation of oxygen during ITZO film growth and reduced the concentration of deep-level defects associated with oxygen vacancies. Under illumination with no bias stress, device stability and persistent photocurrent were improved with increased oxygen ratio. Bias stress tests of the devices were also performed with and without illumination. While high oxygen ratio growth conditions resulted in decreased deep-level oxygen vacancies in the ITZO material, the same conditions resulted in degradation of the interfacial layer between the ITZO channel and dielectric due to the migration of energetic oxygen ions to the interface. Therefore, when bias stress was applied, increased carrier trap density at the interface led to a decrease in device stability that offsets any improvement in the material itself. In order to take advantage of the improved ITZO material growth at a high oxygen ratio, the interface-related problems must be solved.

International strategic minerals inventory summary report; tin

USGS Publications Warehouse

Sutphin, D.M.; Sabin, A.E.; Reed, B.L.

1990-01-01

The International Strategic Minerals Inventory tin inventory contains records for 56 major tin deposits and districts in 21 countries. These countries accounted for 98 percent of the 10 million metric tons of tin produced in the period 1934-87. Tin is a good alloying metal and is generally nontoxic, and its chief uses are as tinplate for tin cans and as solder in electronics. The 56 locations consist of 39 lode deposits and 17 placers and contain almost 7.5 million metric tons of tin in identified economic resources (R1E) and another 1.5 million metric tons of tin in other resource categories. Most of these resources are in major deposits that have been known for over a hundred years. Lode deposits account for 44 percent of the R1E and 87 percent of the resources in other categories. Placer deposits make up the remainder. Low-income and middle-income countries, including Bolivia and Brazil and countries along the Southeast Asian Tin Belt such as Malaysia, Thailand, and Indonesia account for 91 percent of the R1E resources of tin and for 61 percent of resources in other categories. The United States has less than 0.05 percent of the world's tin R1E in major deposits. Available data suggest that the Soviet Union may have about 4 percent of resources in this category. The industrial market economy countries of the United States, Japan, Federal Republic of Germany, and the United Kingdom are major consumers of tin, whereas the major tin-producing countries generally consume little tin. The Soviet Union and China are both major producers and consumers of tin. At the end of World War II, the four largest tin-producing countries (Bolivia, the Belgian Congo (Zaire), Nigeria, and Malaysia) produced over 80 percent of the world's tin. In 1986, the portion of production from the four largest producers (Malaysia, Brazil, Soviet Union, Indonesia) declined to about 55 percent, while the price of tin rose from about $1,500 to $18,000 per metric ton. In response to tin shortages

Oxidant effect of La(NO3)3·6H2O solution on the crystalline characteristics of nanocrystalline ZrO2 films grown by atomic layer deposition

NASA Astrophysics Data System (ADS)

Oh, Nam Khen; Kim, Jin-Tae; Kang, Goru; An, Jong-Ki; Nam, Minwoo; Kim, So Yeon; Park, In-Sung; Yun, Ju-Young

2017-02-01

Nanocrystalline ZrO2 films were synthesized by atomic layer deposition method using CpZr[N(CH3)2]3 (Cp = C5H5) as the metal precursor and La(NO3)3·6H2O solution as the oxygen source. La element in the deposited ZrO2 films could not be detected as its content was below the resolution limit of the X-ray photoelectron spectroscopy. The alternative introduction of La(NO3)3·6H2O solution to conventionally used H2O as the oxidant effectively altered the crystalline structure, grain size, and surface roughness of the grown ZrO2 films. Specifically, the crystalline structure of the ZrO2 film changed from a mixture of tetragonal and monoclinic phases to monoclinic phase. The average grain size also increased, and the resulting film surface became rougher. The average grain sizes of the ZrO2 films prepared from La(NO3)3·6H2O solution at concentrations of 10, 20, 30, and 40% were 280, 256, 208, and 200 nm, respectively, whereas that prepared using H2O oxidant was 142 nm. However, the concentration of La(NO3)3·6H2O solution minimally influenced the crystalline characteristics of the nanocrystalline ZrO2 films i.e., the crystalline structure, grain size, and surface roughness except for crystallite size.

Chlorinated indium tin oxide electrode by InCl{sub 3} aqueous solution for high-performance organic light-emitting diodes

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

Hu, Yun; Wang, Bo; Wang, Zhao-Kui, E-mail: zkwang@suda.edu.cn, E-mail: lsliao@suda.edu.cn

2016-04-11

The authors develop a facile and effective method to produce the chlorinated indium tin oxide (Cl-ITO) treated by InCl{sub 3} aqueous solution and UV/ozone. The work function of the Cl-ITO achieved by this treatment is as high as 5.69 eV, which is increased by 1.09 eV compared with that of the regular ITO without any treatment. Further investigation proved that the enhancement of the work function is attributed to the formation of In-Cl bonds on the Cl-ITO surface. Green phosphorescent organic light-emitting devices based on the Cl-ITO electrodes exhibit excellent electroluminescence performance, elongating lifetime due to the improvement in hole injection.

Oxygen-ion-migration-modulated bipolar resistive switching and complementary resistive switching in tungsten/indium tin oxide/gold memory device

NASA Astrophysics Data System (ADS)

Wu, Xinghui; Zhang, Qiuhui; Cui, Nana; Xu, Weiwei; Wang, Kefu; Jiang, Wei; Xu, Qixing

2018-06-01

In this paper, we report our investigation of room-temperature-fabricated tungsten/indium tin oxide/gold (W/ITO/Au) resistive random access memory (RRAM), which exhibits asymmetric bipolar resistive switching (BRS) behavior. The device displays good write/erase endurance and data retention properties. The device shows complementary resistive switching (CRS) characteristics after controlling the compliance current. A WO x layer electrically formed at the W/ITO in the forming process. Mobile oxygen ions within ITO migrate toward the electrode/ITO interface and produce a semiconductor-like layer that acts as a free-carrier barrier. The CRS characteristic here can be elucidated in light of the evolution of an asymmetric free-carrier blocking layer at the electrode/ITO interface.

Mineral of the month: tin

USGS Publications Warehouse

Carlin, James F.

2005-01-01

Tin was one of the first metals discovered by humans and, like most metals, tin is rarely used by itself. Most tin is used as a protective coating or as an alloy with other metals in a diverse range of commercial and defense applications.

Laser direct patterning of indium tin oxide for defining a channel of thin film transistor.

PubMed

Wang, Jian-Xun; Kwon, Sang Jik; Han, Jae-Hee; Cho, Eou Sik

2013-11-01

In this work, using a Q-switched diode-pumped neodymium-doped yttrium vanadate (Nd:YVO4, lambda = 1064 nm) laser, a direct patterning of indium tin oxide (ITO) channel was realized on glass substrates and the results were compared and analyzed in terms of the effect of repetition rate, scanning speed on etching characteristics. The results showed that the laser conditions of 40 kHz repetition rate with a scanning speed of 500 mm/s were appropriate for the channeling of ITO electrodes. The length of laser-patterned channel was maintained at about 55 microm. However, residual spikes (about 50 nm in height) of ITO were found to be formed at the edges of the laser ablated area and a few ITO residues remained on the glass substrate after laser scanning. By dipping the laser-ablated ITO film in ITO diluted etchant (ITO etchant/DI water: 1/10) at 50 degrees C for 3 min, the spikes and residual ITO were effectively removed. At last, using the laser direct patterning, a bottom-source-drain indium gallium zinc oxide thin film transistor (IGZO-TFT) was fabricated. It is successfully demonstrated that the laser direct patterning can be utilized instead of photolithography to simplify the fabrication process of TFT channel, resulting in the increase of productivity and reduction of cost.

Production of hydrogen using nanocrystalline protein-templated catalysts on m13 phage.

PubMed

Neltner, Brian; Peddie, Brian; Xu, Alex; Doenlen, William; Durand, Keith; Yun, Dong Soo; Speakman, Scott; Peterson, Andrew; Belcher, Angela

2010-06-22

For decades, ethanol has been in use as a fuel for the storage of solar energy in an energy-dense, liquid form. Over the past decade, the ability to reform ethanol into hydrogen gas suitable for a fuel cell has drawn interest as a way to increase the efficiency of both vehicles and stand-alone power generators. Here we report the use of extremely small nanocrystalline materials to enhance the performance of 1% Rh/10% Ni@CeO(2) catalysts in the oxidative steam reforming of ethanol with a ratio of 1.7:1:10:11 (air/EtOH/water/argon) into hydrogen gas, achieving 100% conversion of ethanol at only 300 degrees C with 60% H(2) in the product stream and less than 0.5% CO. Additionally, nanocrystalline 10% Ni@CeO(2) was shown to achieve 100% conversion of ethanol at 400 degrees C with 73% H(2), 2% CO, and 2% CH(4) in the product stream. Finally, we demonstrate the use of biological templating on M13 to improve the resistance of this catalyst to deactivation over 52 h tests at high flow rates (120 000 h(-1) GHSV) at 450 degrees C. This study suggests that the use of highly nanocrystalline, biotemplated catalysts to improve activity and stability is a promising route to significant gains over traditional catalyst manufacture methods.

Micro-scale patterning of indium tin oxide film by spatially modulated pulsed Nd:YAG laser beam

NASA Astrophysics Data System (ADS)

Lee, Jinsoo; Kim, Seongsu; Lee, Myeongkyu

2012-09-01

Here we demonstrate that indium tin oxide (ITO) films deposited on glass can be directly patterned by a spatially -modulated pulsed Nd-YAG laser beam (wavelength = 1064 nm, pulse width = 6 ns) incident onto the film. This method utilizes a pulsed laser-induced thermo-elastic force exerting on the film which plays a role to detach it from the substrate. Sharp-edged clean patterns with feature size as small as 4 μm could be obtained. The threshold pulse energy density for patterning was estimated to be ˜0.8 J/cm2 for 150 nm-thick ITO film, making it possible to pattern over one square centimeter by a single pulse with energy of 850 mJ. Not only being free from photoresist and chemical etching steps, the presented method can also provide much higher throughput than the tradition photoablation process utilizing a tightly focused beam.

First-principles study of adsorption and diffusion of oxygen on surfaces of TiN, ZrN and HfN

NASA Astrophysics Data System (ADS)

Guo, Fangyu; Wang, Jianchuan; Du, Yong; Wang, Jiong; Shang, Shun-Li; Li, Songlin; Chen, Li

2018-09-01

Using first-principles calculations based on density functional theory, we systematically study the adsorption and diffusion behaviors of single oxygen (O) atom on the (0 0 1) surfaces of TiN, ZrN and HfN nitride coatings. The top of N site (top(N)) is the most energetic favorable site for O atom and followed by the hollow site for all the three nitrides. O atom tends to diffuse on the (0 0 1) surfaces of the nitrides from the top of transition metal top(TM) sites to a neighboring top(TM) sites by avoiding N sites. The adsorption of O on ZrN and HfN is more stable than that on TiN. Our findings could explain the experimental phenomenon that the oxide thickness of TiN is smaller than that of ZrN under the same oxidation conditions.

Applications of low temperature CO-oxidation catalysts to breathable gases

NASA Technical Reports Server (NTRS)

Noordally, Ehsan; Richmond, John R.

1990-01-01

Modifications of tin oxide/precious metal catalysts described for use in CO2 lasers have also been developed for use in other applications; namely, as low temperature CO oxidation components in fire escape hoods/masks for mines, aircrafts, hotels, and offices and in sealed environments, such as hyperbaric chambers and submarines. Tin oxide/precious metal catalysts have been prepared on a variety of high surface area cloth substrates for application in fire escape hoods. These show high and stable CO oxidation capability (10 to the 4th power ppm CO reduced to 10 to the 1st power ppm CO) at GHSV of 37,000 h(-1) with water saturated inlet gas at body heat (37 C) and below. Water vapor plays an important role in the surface state/performance of tin oxide catalyst. Water-resistant formulations have been produced by the introduction of transition metal promoters. Tin oxide/precious metal catalysts have also been developed for CO oxidation in the North Sea diving environment. These are currently in use in a variety of hyperbaric chambers and diving vehicles. Ambient temperature operation and resistance to atmospheric water vapor have been demonstrated, and as a result, they offer a viable alternative to hopcalite or heated catalyst systems. A new range of non-tin oxide based low temperature CO oxidation catalysts is described. They are based on reducible metal oxides promoted with previous metals. Preliminary data on selected materials in the form of both cloth artifacts and shaped pellets are presented. They are expected to be applicable both to the breathable gas application area and to CO2 lasers.

Mineral resource of the month: tin

USGS Publications Warehouse

Carlin, James F.

2011-01-01

Tin was one of the earliest-known metals. Because of its hardening effect on copper, tin was used in bronze implements as early as 3500 B.C. Bronze, a copper-tin alloy that can be sharpened and is hard enough to retain a cutting edge, was used during the Bronze Age in construction tools as well as weapons for hunting and war. The geographical separation between tin-producing and tin-consuming nations greatly influenced the patterns of early trade routes. Historians think that as early as 1500 B.C., Phoenicians traveled by sea to the Cornwall district of England to obtain tin. The pure metal was not used unalloyed until about 600 B.C.

Friction and wear of tin and tin alloys from minus 100 C to 150 C

NASA Technical Reports Server (NTRS)

Buckley, D. H.

1975-01-01

Sliding friction experiments were conducted with an iron (110) single-crystal pin sliding on single and polycrystalline tin and tin alloys. Specimens were examined at various ambient temperatures from -100 to 150 C. Applied loads varied from 1 to 50 grams, and sliding velocity was constant at 0.7 mm/min. Results indicate that the crystal transformation of tin influences the friction coefficient. Friction was higher for the diamond structure (gray tin) than it was for the body-centered tetragonal structure (white tin). Bismuth arrested the crystal transformation, which resulted in constant friction over the temperature range -100 to 150 C. Both copper and aluminum enhanced the kinetics of transformation, with aluminum producing a nearly twofold change in friction with the crystal transformation.

Surface characterization of tin-based inorganic EUV resists

NASA Astrophysics Data System (ADS)

Frederick, Ryan T.; Diulus, J. Trey; Lyubinetsky, Igor; Hutchison, Danielle C.; Olsen, Morgan R.; Nyman, May; Herman, Gregory S.

2018-03-01

Metal oxide nanomaterials have shown promise for use as EUV resists. Recently, significant efforts have focused on tinoxo clusters that have high absorption coefficient Sn centers and radiation sensitive organic ligands. In our studies, we have investigated a β-Keggin butyl-Sn cluster (β-NaSn13), which is charge-neutral and allows studying radiation induced chemistries without interference from counterions. We have used ambient pressure X-ray photoelectron spectroscopy (APXPS) to investigate the contrast properties of the β-NaSn13 in ultrahigh vacuum (UHV) and in the presence of ambient oxygen. These contrast studies indicate that ambient oxygen reduces the dose requirements for the solubility transition of the β-NaSn13 photoresists. APXPS spectra collected before and after the solubility transition shows that ambient oxygen causes a greater loss of butyl ligands from the samples and the formation of more tin oxide for larger doses, suggesting the presence of reactive oxygen species. APXPS was also used to study processes during the post exposure bake, where we compared the differences in film chemistries in ambient oxygen or in UHV. There were only very small differences in the APXPS spectra before exposure and after exposure and the post exposure bake. However, ambient oxygen resulted in some changes for unexposed regions during the post exposure bake; there was a greater ratio of tin oxide to other oxygen species (alkoxy ligands, hydroxyls) for samples annealed in oxygen. These results have significance for EUV and e-beam lithography processing parameters, as well as implications for cluster design and ligand chemistries.

Aging of Nanocrystalline Mackinawite (FeS): Mineralogical and Physicochemical Properties

NASA Astrophysics Data System (ADS)

Jeong, H. Y.; Lee, H.

2011-12-01

Due to the extraordinary physical properties and high surface areas, nanocrystalline minerals have been widely investigated for their potential uses in treating contaminated groundwaters and surface waters. Most previous studies in this field have focused on either preparation of nanocrystalline minerals or measurement of their reactivity with environmental contaminants. Nanocrystalline minerals, due to the inherent thermodynamic instability, tend to change the physicochemical and mineralogical properties over time, usually resulting in the decreased reactivity. Thus, to better assess the long-term effectiveness of nanocrystalline minerals in field applications, such "aging" effects should be clearly delineated. In the present work, we have investigated the aging impact on nanocrystalline mackinawite (FeS), the ubiquitous Fe-bearing mineral in anoxic sulfidic sediments. Mackinawite (FeS) is known to be an effective scavenger for metal pollutants and a strong reducing reagent for chromate and chlorinated organic compounds. Our preliminary results indicate that nanocrystalline FeS ages via Ostwald ripening, particle aggregation, or mineralogical transformation. By X-ray diffraction (XRD) analysis, aging of nanocrystalline FeS via Ostwald ripening is found to be dominant at acidic pH. Cryogenic transmission electron microscopy (TEM) shows that particle aggregation is most evident at neutral pH. Transformation of nanosized FeS into a more thermodynamically stable greigite (Fe3S4) is observed in the presence of folic acid at acidic pH. The pH-dependent aging process may be linked with changes in the apparent solubility and surface charge of FeS with pH. The Ostwald ripening or particle aggregation of nanocrystalline FeS leads to the decrease surface area, thus causing the decreased reactivity. Given the less reactivity of greigite, the transformation of nanocrystalline FeS to greigite is also expected to result in the decreased reactivity.

Generation of laser-induced periodic surface structures in indium-tin-oxide thin films and two-photon lithography of ma-N photoresist by sub-15 femtosecond laser microscopy for liquid crystal cell application

NASA Astrophysics Data System (ADS)

Klötzer, Madlen; Afshar, Maziar; Feili, Dara; Seidel, Helmut; König, Karsten; Straub, Martin

2015-03-01

Indium-tin-oxide (ITO) is a widely used electrode material for liquid crystal cell applications because of its transparency in the visible spectral range and its high electrical conductivity. Important examples of applications are displays and optical phase modulators. We report on subwavelength periodic structuring and precise laser cutting of 150 nm thick indium-tin-oxide films on glass substrates, which were deposited by magnetron reactive DC-sputtering from an indiumtin target in a low-pressure oxygen atmosphere. In order to obtain nanostructured electrodes laser-induced periodic surface structures with a period of approximately 100 nm were generated using tightly focused high-repetition rate sub-15 femtosecond pulsed Ti:sapphire laser light, which was scanned across the sample by galvanometric mirrors. Three-dimensional spacers were produced by multiphoton photopolymerization in ma-N 2410 negative-tone photoresist spin-coated on top of the ITO layers. The nanostructured electrodes were aligned in parallel to set up an electrically switchable nematic liquid crystal cell.

Determination of total tin in geological materials by electrothermal atomic-absorption spectrophotometry using a tungsten-impregnated graphite furnace

USGS Publications Warehouse

Zhou, L.; Chao, T.T.; Meier, A.L.

1984-01-01

An electrothermal atomic-absorption spectrophotometric method is described for the determination of total tin in geological materials, with use of a tungsten-impregnated graphite furnace. The sample is decomposed by fusion with lithium metaborate and the melt is dissolved in 10% hydrochloric acid. Tin is then extracted into trioctylphosphine oxide-methyl isobutyl ketone prior to atomization. Impregnation of the furnace with a sodium tungstate solution increases the sensitivity of the determination and improves the precision of the results. The limits of determination are 0.5-20 ppm of tin in the sample. Higher tin values can be determined by dilution of the extract. Replicate analyses of eighteen geological reference samples with diverse matrices gave relative standard deviations ranging from 2.0 to 10.8% with an average of 4.6%. Average tin values for reference samples were in general agreement with, but more precise than, those reported by others. Apparent recoveries of tin added to various samples ranged from 95 to 111% with an average of 102%. ?? 1984.

Polarization-Insensitive Surface Plasmon Polarization Electro-Absorption Modulator Based on Epsilon-Near-Zero Indium Tin Oxide.

PubMed

Jin, Lin; Wen, Long; Liang, Li; Chen, Qin; Sun, Yunfei

2018-02-03

CMOS-compatible plasmonic modulators operating at the telecom wavelength are significant for a variety of on-chip applications. Relying on the manipulation of the transverse magnetic (TM) mode excited on the metal-dielectric interface, most of the previous demonstrations are designed to response only for specific polarization state. In this case, it will lead to a high polarization dependent loss, when the polarization-sensitive modulator integrates to a fiber with random polarization state. Herein, we propose a plasmonic modulator utilizing a metal-oxide indium tin oxide (ITO) wrapped around the silicon waveguide and investigate its optical modulation ability for both the vertical and horizontal polarized guiding light by tuning electro-absorption of ITO with the field-induced carrier injection. The electrically biased modulator with electron accumulated at the ITO/oxide interface allows for epsilon-near-zero (ENZ) mode to be excited at the top or lateral portion of the interface depending on the polarization state of the guiding light. Because of the high localized feature of ENZ mode, efficient electro-absorption can be achieved under the "OFF" state of the device, thus leading to large extinction ratio (ER) for both polarizations in our proposed modulator. Further, the polarization-insensitive modulation is realized by properly tailoring the thickness of oxide in two different stacking directions and therefore matching the ER values for device operating at vertical and horizontal polarized modes. For the optimized geometry configuration, the difference between the ER values of two polarization modes, i.e., the ΔER, as small as 0.01 dB/μm is demonstrated and, simultaneously with coupling efficiency above 74%, is obtained for both polarizations at a wavelength of 1.55 μm. The proposed plasmonic-combined modulator has a potential application in guiding and processing of light from a fiber with a random polarization state.

Polarization-Insensitive Surface Plasmon Polarization Electro-Absorption Modulator Based on Epsilon-Near-Zero Indium Tin Oxide

NASA Astrophysics Data System (ADS)

Jin, Lin; Wen, Long; Liang, Li; Chen, Qin; Sun, Yunfei

2018-02-01

CMOS-compatible plasmonic modulators operating at the telecom wavelength are significant for a variety of on-chip applications. Relying on the manipulation of the transverse magnetic (TM) mode excited on the metal-dielectric interface, most of the previous demonstrations are designed to response only for specific polarization state. In this case, it will lead to a high polarization dependent loss, when the polarization-sensitive modulator integrates to a fiber with random polarization state. Herein, we propose a plasmonic modulator utilizing a metal-oxide indium tin oxide (ITO) wrapped around the silicon waveguide and investigate its optical modulation ability for both the vertical and horizontal polarized guiding light by tuning electro-absorption of ITO with the field-induced carrier injection. The electrically biased modulator with electron accumulated at the ITO/oxide interface allows for epsilon-near-zero (ENZ) mode to be excited at the top or lateral portion of the interface depending on the polarization state of the guiding light. Because of the high localized feature of ENZ mode, efficient electro-absorption can be achieved under the "OFF" state of the device, thus leading to large extinction ratio (ER) for both polarizations in our proposed modulator. Further, the polarization-insensitive modulation is realized by properly tailoring the thickness of oxide in two different stacking directions and therefore matching the ER values for device operating at vertical and horizontal polarized modes. For the optimized geometry configuration, the difference between the ER values of two polarization modes, i.e., the ΔER, as small as 0.01 dB/μm is demonstrated and, simultaneously with coupling efficiency above 74%, is obtained for both polarizations at a wavelength of 1.55 μm. The proposed plasmonic-combined modulator has a potential application in guiding and processing of light from a fiber with a random polarization state.

AFM, CLSM and EIS characterization of the immobilization of antibodies on indium-tin oxide electrode and their capture of Legionella pneumophila.

PubMed

Souiri, Mina; Blel, Nesrine; Sboui, Dejla; Mhamdi, Lotfi; Epalle, Thibaut; Mzoughi, Ridha; Riffard, Serge; Othmane, Ali

2014-01-01

The microscopic surface molecular structures and properties of monoclonal anti-Legionella pneumophila antibodies on an indium-tin oxide (ITO) electrode surface were studied to elaborate an electrochemical immunosensor for Legionella pneumophila detection. A monoclonal anti-Legionella pneumophila antibody (MAb) has been immobilized onto an ITO electrode via covalent chemical bonds between antibodies amino-group and the ring of (3-Glycidoxypropyl) trimethoxysilane (GPTMS). The functionalization of the immunosensor was characterized by atomic force microscopy (AFM), water contact angle measurement, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in the presence of [Fe(CN)₆](3-/4-) as a redox probe. Specific binding of Legionella pneumophila sgp 1 cells onto the antibody-modified ITO electrode was shown by confocal laser scanning microscopy (CLSM) imaging and EIS. AFM images evidenced the dense and relatively homogeneous morphology on the ITO surface. The formation of the complex epoxysilane-antibodies acting as barriers for the electron transfer between the electrode surface and the redox species in the solution induced a significant increase in the charge transfer resistance (Rct) compared to all the electric elements. A linear relationship between the change in charge transfer resistance (ΔRct=Rct after immunoreactions - Rct control) and the logarithmic concentration value of L. pneumophila was observed in the range of 5 × 10(1)-5 × 10(4) CFU mL(-1) with a limit of detection 5 × 10(1)CFU mL(-1). The present study has demonstrated the successful deposition of an anti-L. pneumophila antibodies on an indium-tin oxide surface, opening its subsequent use as immuno-captor for the specific detection of L. pneumophila in environmental samples. © 2013 Elsevier B.V. All rights reserved.

Effect of Sn on the oxide subscale structure formed on a 3% Si steel

NASA Astrophysics Data System (ADS)

Cesar, Maria das G. M. M.; Silveira, Carolina C.; Paolinelli, Sebastião C.; Cicale, Stefano

2018-04-01

Addition of tin in 3% Si steel is a method to improve magnetic properties since tin in steel is known as an element that segregates at grain boundaries, inhibits grain growth and has a dragging effect on grain boundary movement. However, tin is generally known as an element that has a harmful effect on surface coating properties. The oxide subscale formed on the decarburization annealing of a 3% Si steel containing tin was investigated by SEM, EDS, GDS and FTIR. The forsterite film was evaluated by SEM, EDS and GDS. The higher tin content decreased thickness, oxygen and fayalite/silica ratio in the subscale and resulted into a discontinuous forsterite film with poor oxidation resistance. After secondary coating the samples presented a reddish color due to the formation of iron oxide and poor dielectric property.

High-efficiency solar cells fabricated from direct-current magnetron sputtered n-indium tin oxide onto p-InP grown by atmospheric pressure metalorganic vapor phase epitaxy

NASA Technical Reports Server (NTRS)

Li, X.; Wanlass, M. W.; Gessert, T. A.; Emery, K. A.; Coutts, T. J.

1989-01-01

An attempt is made to improve device efficiencies by depositing indium tin oxide onto epitaxially grown p-InP on p(+)-InP substrates. This leads to a reduction in the device series resistance, high-quality reproducible surfaces, and an improvement in the transport properties of the base layer. Moreover, many of the facets associated with badly characterized bulk liquid encapsulated Czochralski substrates used in previous investigations are removed in this way.

Parametrization of optical properties of indium-tin-oxide thin films by spectroscopic ellipsometry: Substrate interfacial reactivity

NASA Astrophysics Data System (ADS)

Losurdo, M.; Giangregorio, M.; Capezzuto, P.; Bruno, G.; de Rosa, R.; Roca, F.; Summonte, C.; Plá, J.; Rizzoli, R.

2002-01-01

Indium-tin-oxide (ITO) films deposited by sputtering and e-gun evaporation on both transparent (Corning glass) and opaque (c-Si, c-Si/SiO2) substrates and in c-Si/a-Si:H/ITO heterostructures have been analyzed by spectroscopic ellipsometry (SE) in the range 1.5-5.0 eV. Taking the SE advantage of being applicable to absorbent substrate, ellipsometry is used to determine the spectra of the refractive index and extinction coefficient of the ITO films. The effect of the substrate surface on the ITO optical properties is focused and discussed. To this aim, a parametrized equation combining the Drude model, which considers the free-carrier response at the infrared end, and a double Lorentzian oscillator, which takes into account the interband transition contribution at the UV end, is used to model the ITO optical properties in the useful UV-visible range, whatever the substrate and deposition technique. Ellipsometric analysis is corroborated by sheet resistance measurements.

Better Organic Ternary Memory Performance through Self-Assembled Alkyltrichlorosilane Monolayers on Indium Tin Oxide (ITO) Surfaces.

PubMed

Hou, Xiang; Cheng, Xue-Feng; Zhou, Jin; He, Jing-Hui; Xu, Qing-Feng; Li, Hua; Li, Na-Jun; Chen, Dong-Yun; Lu, Jian-Mei

2017-11-16

Recently, surface engineering of the indium tin oxide (ITO) electrode of sandwich-like organic electric memory devices was found to effectively improve their memory performances. However, there are few methods to modify the ITO substrates. In this paper, we have successfully prepared alkyltrichlorosilane self-assembled monolayers (SAMs) on ITO substrates, and resistive random access memory devices are fabricated on these surfaces. Compared to the unmodified ITO substrates, organic molecules (i.e., 2-((4-butylphenyl)amino)-4-((4-butylphenyl)iminio)-3-oxocyclobut-1-en-1-olate, SA-Bu) grown on these SAM-modified ITO substrates have rougher surface morphologies but a smaller mosaicity. The organic layer on the SAM-modified ITO further aged to eliminate the crystalline phase diversity. In consequence, the ternary memory yields are effectively improved to approximately 40-47 %. Our results suggest that the insertion of alkyltrichlorosilane self-assembled monolayers could be an efficient method to improve the performance of organic memory devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mechanical and optoelectric properties of post-annealed fluorine-doped tin oxide films by ultraviolet laser irradiation

NASA Astrophysics Data System (ADS)

Tseng, Shih-Feng; Hsiao, Wen-Tse; Chiang, Donyau; Huang, Kuo-Cheng; Chou, Chang-Pin

2011-06-01

The fluorine-doped tin oxide (FTO) thin film deposited on a soda-lime glass substrate was annealed by a defocus ultraviolet (UV) laser irradiation at ambient temperature. The mechanical and optoelectric properties of FTO films annealed by using the various laser processing parameters were reported. After the FTO films were subjected to laser post-annealing, the microhardness were slightly less but the reduced modulus values were larger than that of unannealed FTO films, respectively. The average optical transmittance in the visible waveband slightly increased with increasing the laser annealing energy and scan speed. Moreover, all the sheet resistance of laser annealed films was less than that of the unannealed ones. We found that the sheet resistance decrease was obviously influenced by annealing. The suitable annealing conditions could maintain the film thickness and relief the internal stress generated in the film preparation process to improve the electrical conductivity via decreasing laser energy or increasing scan speed.

Wet etching mechanism and crystallization of indium-tin oxide layer for application in light-emitting diodes

NASA Astrophysics Data System (ADS)

Su, Shui-Hsiang; Kong, Hsieng-Jen; Tseng, Chun-Lung; Chen, Guan-Yu

2018-01-01

In the article, we describe the etching mechanism of indium-tin oxide (ITO) film, which was wet-etched using a solution of hydrochloric acid (HCl) and ferric chloride (FeCl3). The etching mechanism is analyzed at various etching durations of ITO films by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), and selective area diffraction (SAD) analysis. In comparison with the crystalline phase of SnO2, the In2O3 phase can be more easily transformed to In3+ and can form an inverted conical structure during the etching process. By adjusting the etching duration, the residual ITO is completely removed to show a designed pattern. This is attributed to the negative Gibbs energy of In2O3 transformed to In3+. The result also corresponds to the finding of energy-dispersive X-ray spectroscopy (EDS) analysis that the Sn/In ratio increases with increasing etching duration.

Highly ultraviolet transparent textured indium tin oxide thin films and the application in light emitting diodes

NASA Astrophysics Data System (ADS)

Chen, Zimin; Zhuo, Yi; Tu, Wenbin; Ma, Xuejin; Pei, Yanli; Wang, Chengxin; Wang, Gang

2017-06-01

Various kinds of materials have been developed as transparent conductors for applications in semiconductor optoelectronic devices. However, there is a bottleneck that transparent conductive materials lose their transparency at ultraviolet (UV) wavelengths and could not meet the demands for commercial UV device applications. In this work, textured indium tin oxide (ITO) is grown and its potential to be used at UV wavelengths is explored. It is observed that the pronounced Burstein-Moss effect could widen the optical bandgap of the textured ITO to 4.7 eV. The average transmittance in UVA (315 nm-400 nm) and UVB (280 nm-315 nm) ranges is as high as 94% and 74%, respectively. The excellent optical property of textured ITO is attributed to its unique structural property. The compatibility of textured ITO thin films to the device fabrication is demonstrated on 368-nm nitride-based light emitting diodes, and the enhancement of light output power by 14.8% is observed compared to sputtered ITO.

Comparative study of ITO and TiN fabricated by low-temperature RF biased sputtering

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

Simon, Daniel K., E-mail: daniel.simon@namlab.com; Schenk, Tony; Dirnstorfer, Ingo

2016-03-15

Radio frequency (RF) biasing induced by a second plasma source at the substrate is applied to low-temperature sputtering processes for indium tin oxide (ITO) and titanium nitride (TiN) thin films. Investigations on crystal structure and surface morphology show that RF-biased substrate plasma processes result in a changed growth regime with different grain sizes and orientations than those produced by processes without a substrate bias. The influence of the RF bias is shown comparatively for reactive RF-sputtered ITO and reactive direct-current-sputtered TiN. The ITO layers exhibit an improved electrical resistivity of 0.5 mΩ cm and an optical absorption coefficient of 0.5 × 10{sup 4 }cm{supmore » −1} without substrate heating. Room-temperature sputtered TiN layers are deposited that possess a resistivity (0.1 mΩ cm) of 3 orders of magnitude lower than, and a density (5.4 g/cm{sup 3}) up to 45% greater than, those obtained from layers grown using the standard process without a substrate plasma.« less

Sputter deposition of indium tin oxide onto zinc pthalocyanine: Chemical and electronic properties of the interface studied by photoelectron spectroscopy

NASA Astrophysics Data System (ADS)

Gassmann, Jürgen; Brötz, Joachim; Klein, Andreas

2012-02-01

The interface chemistry and the energy band alignment at the interface formed during sputter deposition of transparent conducting indium tin oxide (ITO) onto the organic semiconductor zinc phtalocyanine (ZnPc), which is important for inverted, transparent, and stacked organic light emitting diodes, is studied by in situ photoelectron spectroscopy (XPS and UPS). ITO was sputtered at room temperature and a low power density with a face to face arrangement of the target and substrate. With these deposition conditions, no chemical reaction and a low barrier height for charge injection at this interface are observed. The barrier height is comparable to those observed for the reverse deposition sequence, which also confirms the absence of sputter damage.

Tin Whisker Testing and Modeling

DTIC Science & Technology

2015-11-01

FINAL REPORT Tin Whisker Testing and Modeling SERDP Project WP-1753 NOVEMBER 2015 Stephan J. Meschter Polina Snugovsky BAE Systems...lead (Pb) is that component manufacturers have primarily switched to tin -rich finishes and solder alloys in commercial-off-the-shelf products...Unfortunately, this creates an increased risk of tin whisker formation that can result in undesirable electrical failures unless military and aerospace

Electrical properties of tin-doped zinc oxide nanostructures doped at different dopant concentrations

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

Nasir, M. F., E-mail: babaibaik2002@yahoo.com; Zainol, M. N., E-mail: nizarzainol@yahoo.com; Hannas, M., E-mail: mhannas@gmail.com

This project has been focused on the electrical and optical properties respectively on the effect of Tin doped zinc oxide (ZnO) thin films at different dopant concentrations. These thin films were doped with different Sn dopant concentrations at 1 at%, 2 at%, 3 at%, 4 at% and 5 at% was selected as the parameter to optimize the thin films quality while the annealing temperature is fixed 500 °C. Sn doped ZnO solutions were deposited onto the glass substrates using sol-gel spin coating method. This project was involved with three phases, which are thin films preparation, deposition and characterization. The thinmore » films were characterized using Current Voltage (I-V) measurement and ultraviolet-visible-near-infrared (UV-vis-NIR) spectrophotometer (Perkin Elmer Lambda 750) for electrical properties and optical properties. The electrical properties show that the resistivity is the lowest at 4 at% Sn doping concentration with the value 3.08 × 10{sup 3} Ωcm{sup −1}. The absorption coefficient spectrum obtained shows all films exhibit very low absorption in the visible (400-800 nm) and near infrared (NIR) (>800 nm) range but exhibit high absorption in the UV range.« less

Surface modification and characterization of indium-tin oxide for organic light-emitting devices.

PubMed

Zhong, Z Y; Jiang, Y D

2006-10-15

In this work, we used different treatment methods (ultrasonic degreasing, hydrochloric acid treatment, and oxygen plasma) to modify the surfaces of indium-tin oxide (ITO) substrates for organic light-emitting devices. The surface properties of treated ITO substrates were studied by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), sheet resistance, contact angle, and surface energy measurements. Experimental results show that the ITO surface properties are closely related to the treatment methods, and the oxygen plasma is more efficient than the other treatments since it brings about smoother surfaces, lower sheet resistance, higher work function, and higher surface energy and polarity of the ITO substrate. Moreover, polymer light-emitting electrochemical cells (PLECs) with differently treated ITO substrates as device electrodes were fabricated and characterized. It is found that surface treatments of ITO substrates have a certain degree of influence upon the injection current, brightness, and efficiency, but hardly upon the turn-on voltages of current injection and light emission, which are in agreement with the measured optical energy gap of the electroluminescent polymer. The oxygen plasma treatment on the ITO substrate yields the best performance of PLECs, due to the improvement of interface formation and electrical contact of the ITO substrate with the polymer blend in the PLECs.

Design of photonic crystal surface emitting lasers with indium-tin-oxide top claddings

NASA Astrophysics Data System (ADS)

Huang, Shen-Che; Hong, Kuo-Bin; Chiu, Han-Lun; Lan, Shao-Wun; Chang, Tsu-Chi; Li, Heng; Lu, Tien-Chang

2018-02-01

Electrically pumped GaAs-based photonic crystal surface emitting lasers were fabricated using a simple fabrication process by directly capping the indium-tin-oxide transparent conducting thin film as the top cladding layer upon a photonic crystal layer. Optimization of the separate-confinement heterostructures of a laser structure is crucial to improving characteristics by providing advantageous optical confinements. The turn-on voltage, series resistance, threshold current, and slope efficiency of the laser with a 100 × 100 μm2 photonic crystal area operated at room temperature were 1.3 V, 1.5 Ω, 121 mA, and 0.2 W/A, respectively. Furthermore, we demonstrated a single-lobed lasing wavelength of 928.6 nm at 200 mA and a wavelength redshift rate of 0.05 nm/K in temperature-dependent measurements. The device exhibited the maximum output power of approximately 400 mW at an injection current of 2 A; moreover, divergence angles of less than 1° for the unpolarized circular-shaped laser beam were measured at various injection currents. Overall, the low threshold current, excellent beam quality, small divergence, high output power, and high-operating-temperature (up to 343 K) of our devices indicate that they can potentially fill the requirements for next-generation light sources and optoelectronic devices.

Synthesis and mechanical/magnetic properties of nano-grained iron-oxides prepared with an inert gas condensation and pulse electric current sintering process

NASA Astrophysics Data System (ADS)

Choa, Yong-Ho; Nakayama, Tatachika; Sekino, Tohru; Niihara, Koichi

1999-04-01

Nanocrystalline iron-oxide powder was fabricated with an inert gas condensation (IGC) method combined with evaporation, and in-situ oxidation techniques. The particle size of iron-oxide powder was controlled by varying the helium gas pressure between 0.1 and 10 Torr, with the smallest one =10 nm at 0.1 Torr. The nanostructure was characterized by TEM. Nanocrystalline iron-oxide powder was sintered with the pulse electric current sintering (PECS) method to obtain densified γ-Fe2O3 materials, and suitably densified nano-grained γ-Fe2O3 materials (≈ 40 nm) of great hardness were obtained. The correlation between the nanostructure and magnetic properties of nanocrystalline powder and densified γ-Fe2O3 materials was also investigated.

Fully transparent flexible tin-doped zinc oxide thin film transistors fabricated on plastic substrate.

PubMed

Han, Dedong; Zhang, Yi; Cong, Yingying; Yu, Wen; Zhang, Xing; Wang, Yi

2016-12-12

In this work, we have successfully fabricated bottom gate fully transparent tin-doped zinc oxide thin film transistors (TZO TFTs) fabricated on flexible plastic substrate at low temperature by RF magnetron sputtering. The effect of O 2 /Ar gas flow ratio during channel deposition on the electrical properties of TZO TFTs was investigated, and we found that the O 2 /Ar gas flow ratio have a great influence on the electrical properties. TZO TFTs on flexible substrate has very nice electrical characteristics with a low off-state current (I off ) of 3 pA, a high on/off current ratio of 2 × 10 7 , a high saturation mobility (μ sat ) of 66.7 cm 2 /V•s, a steep subthreshold slope (SS) of 333 mV/decade and a threshold voltage (V th ) of 1.2 V. Root-Mean-Square (RMS) roughness of TZO thin film is about 0.52 nm. The transmittance of TZO thin film is about 98%. These results highlight that the excellent device performance can be realized in TZO film and TZO TFT can be a promising candidate for flexible displays.

Fully transparent flexible tin-doped zinc oxide thin film transistors fabricated on plastic substrate

NASA Astrophysics Data System (ADS)

Han, Dedong; Zhang, Yi; Cong, Yingying; Yu, Wen; Zhang, Xing; Wang, Yi

2016-12-01

In this work, we have successfully fabricated bottom gate fully transparent tin-doped zinc oxide thin film transistors (TZO TFTs) fabricated on flexible plastic substrate at low temperature by RF magnetron sputtering. The effect of O2/Ar gas flow ratio during channel deposition on the electrical properties of TZO TFTs was investigated, and we found that the O2/Ar gas flow ratio have a great influence on the electrical properties. TZO TFTs on flexible substrate has very nice electrical characteristics with a low off-state current (Ioff) of 3 pA, a high on/off current ratio of 2 × 107, a high saturation mobility (μsat) of 66.7 cm2/V•s, a steep subthreshold slope (SS) of 333 mV/decade and a threshold voltage (Vth) of 1.2 V. Root-Mean-Square (RMS) roughness of TZO thin film is about 0.52 nm. The transmittance of TZO thin film is about 98%. These results highlight that the excellent device performance can be realized in TZO film and TZO TFT can be a promising candidate for flexible displays.

Indium-tin-oxide nanowhiskers crystalline silicon photovoltaics combining micro- and nano-scale surface textures

NASA Astrophysics Data System (ADS)

Chang, C. H.; Hsu, M. H.; Chang, W. L.; Sun, W. C.; Yu, Peichen

2011-02-01

In this work, we present a solution that employs combined micro- and nano-scale surface textures to increase light harvesting in the near infrared for crystalline silicon photovoltaics, and discuss the associated antireflection and scattering mechanisms. The combined surface textures are achieved by uniformly depositing a layer of indium-tin-oxide nanowhiskers on passivated, micro-grooved silicon solar cells using electron-beam evaporation. The nanowhiskers facilitate optical transmission in the near-infrared, which is optically equivalent to a stack of two dielectric thin-films with step- and graded- refractive index profiles. The ITO nanowhiskers provide broadband anti-reflective properties (R<5%) in the wavelength range of 350-1100nm. In comparison with conventional Si solar cell, the combined surface texture solar cell shows higher external quantum efficiency (EQE) in the range of 700-1100nm. Moreover, the ITO nano-whisker coating Si solar cell shows a high total efficiency increase of 1.1% (from 16.08% to17.18%). Furthermore, the nano-whiskers also provide strong forward scattering for ultraviolet and visible light, favorable in thin-wafer silicon photovoltaics to increase the optical absorption path.

Studies on high electronic energy deposition in transparent conducting indium tin oxide thin films

NASA Astrophysics Data System (ADS)

Deshpande, N. G.; Gudage, Y. G.; Ghosh, A.; Vyas, J. C.; Singh, F.; Tripathi, A.; Sharma, Ramphal

2008-02-01

We have examined the effect of swift heavy ions using 100 MeV Au8+ ions on the electrical properties of transparent, conducting indium tin oxide polycrystalline films with resistivity of 0.58 × 10-4 Ω cm and optical transmission greater than 78% (pristine). We report on the modifications occurring after high electronic energy deposition. With the increase in fluency, x-ray line intensity of the peaks corresponding to the planes (1 1 0), (4 0 0), (4 4 1) increased, while (3 3 1) remained constant. Surface morphological studies showed a pomegranate structure of pristine samples, which was highly disturbed with a high dose of irradiation. For the high dose, there was a formation of small spherical domes uniformly distributed over the entire surface. The transmittance was seen to be decreasing with the increase in ion fluency. At higher doses, the resistivity and photoluminescence intensity was seen to be decreased. In addition, the carrier concentration was seen to be increased, which was in accordance with the decrease in resistivity. The observed modifications after high electronic energy deposition in these films may lead to fruitful device applications.

Synthesis of Nano-Crystalline Gamma-TiAl Materials

NASA Technical Reports Server (NTRS)

Hales, Stephen J.; Vasquez, Peter

2003-01-01

One of the principal problems with nano-crystalline materials is producing them in quantities and sizes large enough for valid mechanical property evaluation. The purpose of this study was to explore an innovative method for producing nano-crystalline gamma-TiAl bulk materials using high energy ball milling and brief secondary processes. Nano-crystalline powder feedstock was produced using a Fritsch P4(TM) vario-planetary ball mill recently installed at NASA-LaRC. The high energy ball milling process employed tungsten carbide tooling (vials and balls) and no process control agents to minimize contamination. In a collaborative effort, two approaches were investigated, namely mechanical alloying of elemental powders and attrition milling of pre-alloyed powders. The objective was to subsequently use RF plasma spray deposition and short cycle vacuum hot pressing in order to effect consolidation while retaining nano-crystalline structure in bulk material. Results and discussion of the work performed to date are presented.

Formation of hydrothermal tin deposits: Raman spectroscopic evidence for an important role of aqueous Sn(IV) species

NASA Astrophysics Data System (ADS)

Schmidt, Christian

2018-01-01

The speciation of tin and the solubility of cassiterite in H2O + HCl were determined at temperatures to 600 °C using in situ Raman spectroscopy. In addition, information on the fluid-melt partition of Sn was obtained at 700 °C and indicated a preference of the fluid only at HCl concentrations that are much higher than in fluids exsolved from natural felsic melts. Dissolution of cassiterite generally resulted in formation of Sn(IV) species unless reduced conditions were generated by hydrogen permeation or carbohydrates in the starting material. The prevalent aqueous Sn(IV) species was [SnCl4(H2O)2]0, with additional [SnCl3(H2O)3]+ and [SnCl5(H2O)]-. The only detectable Sn(II) species was very likely [Sn(II)Cl3]-. Cassiterite solubility increased with HCl concentration and was generally high in H2O+HCl fluids, with no strong dependencies on temperature, pressure, or the oxidation state of tin in the fluid. The Sn(IV) concentrations at 500 and 600 °C determined from the integrated ν1[Sn(IV)sbnd Cl] band intensity are in good agreement with literature data on the cassiterite solubility in H2O + HCl at oxygen fugacities along the hematite-magnetite buffer. The combined results from previous experimental studies and this study demonstrate that HCl molality is a crucial parameter for hydrothermal mobilization and transport of tin and for cassiterite precipitation, and that pH, pressure and temperature are less important. Current models on hydrothermal tin deposit formation need to be augmented to include Sn(IV)sbnd Cl complexes as significant tin-transporting species. Irrespective of the oxidation state of tin in the fluid, cassiterite precipitates due to reaction of the hydrothermal fluid with the wall rock (greisen or skarn formation), dilution (mixing with meteoric water) or a decrease in the HCl activity in the aqueous liquid by boiling. A redox reaction is only required for tin transported as Sn(II) to be converted to Sn(IV).

Effect of replacement of tin doped indium oxide (ITO) by ZnO: analysis of environmental impact categories

NASA Astrophysics Data System (ADS)

Ziemińska-Stolarska, Aleksandra; Barecka, Magda; Zbiciński, Ireneusz

2017-10-01

Abundant use of natural resources is doubtlessly one of the greatest challenges of sustainable development. Process alternatives, which enable sustainable manufacturing of valuable products from more accessible resources, are consequently required. One of examples of limited resources is Indium, currently broadly used for tin doped indium oxide (ITO) for production of transparent conductive films (TCO) in electronics industry. Therefore, candidates for Indium replacement, which would offer as good performance as the industrial state-of-the-art technology based on ITO are widely studied. However, the environmental impact of new layers remains unknown. Hence, this paper studies the environmental effect of ITO replacement by zinc oxide (ZnO) by means life cycle assessment (LCA) methodology. The analysis enables to quantify the environmental impact over the entire period of life cycle of products—during manufacturing, use phase and waste generation. The analysis was based on experimental data for deposition process. Further, analysis of different impact categories was performed in order to determine specific environmental effects related to technology change. What results from the analysis, is that ZnO is a robust alternative material for ITO replacement regarding environmental load and energy efficiency of deposition process which is also crucial for sustainable TCO layer production.

Optical Detection of Ketoprofen by Its Electropolymerization on an Indium Tin Oxide-Coated Optical Fiber Probe.

PubMed

Bogdanowicz, Robert; Niedziałkowski, Paweł; Sobaszek, Michał; Burnat, Dariusz; Białobrzeska, Wioleta; Cebula, Zofia; Sezemsky, Petr; Koba, Marcin; Stranak, Vitezslav; Ossowski, Tadeusz; Śmietana, Mateusz

2018-04-27

In this work an application of optical fiber sensors for real-time optical monitoring of electrochemical deposition of ketoprofen during its anodic oxidation is discussed. The sensors were fabricated by reactive magnetron sputtering of indium tin oxide (ITO) on a 2.5 cm-long core of polymer-clad silica fibers. ITO tuned in optical properties and thickness allows for achieving a lossy-mode resonance (LMR) phenomenon and it can be simultaneously applied as an electrode in an electrochemical setup. The ITO-LMR electrode allows for optical monitoring of changes occurring at the electrode during electrochemical processing. The studies have shown that the ITO-LMR sensor’s spectral response strongly depends on electrochemical modification of its surface by ketoprofen. The effect can be applied for real-time detection of ketoprofen. The obtained sensitivities reached over 1400 nm/M (nm·mg −1 ·L) and 16,400 a.u./M (a.u.·mg −1 ·L) for resonance wavelength and transmission shifts, respectively. The proposed method is a valuable alternative for the analysis of ketoprofen within the concentration range of 0.25⁻250 μg mL −1 , and allows for its determination at therapeutic and toxic levels. The proposed novel sensing approach provides a promising strategy for both optical and electrochemical detection of electrochemical modifications of ITO or its surface by various compounds.

In-situ Observation of Cross-Sectional Microstructural Changes and Stress Distributions in Fracturing TiN Thin Film during Nanoindentation

PubMed Central

Zeilinger, Angelika; Todt, Juraj; Krywka, Christina; Müller, Martin; Ecker, Werner; Sartory, Bernhard; Meindlhumer, Michael; Stefenelli, Mario; Daniel, Rostislav; Mitterer, Christian; Keckes, Jozef

2016-01-01

Load-displacement curves measured during indentation experiments on thin films depend on non-homogeneous intrinsic film microstructure and residual stress gradients as well as on their changes during indenter penetration into the material. To date, microstructural changes and local stress concentrations resulting in plastic deformation and fracture were quantified exclusively using numerical models which suffer from poor knowledge of size dependent material properties and the unknown intrinsic gradients. Here, we report the first in-situ characterization of microstructural changes and multi-axial stress distributions in a wedge-indented 9 μm thick nanocrystalline TiN film volume performed using synchrotron cross-sectional X-ray nanodiffraction. During the indentation, needle-like TiN crystallites are tilted up to 15 degrees away from the indenter axis in the imprint area and strongly anisotropic diffraction peak broadening indicates strain variation within the X-ray nanoprobe caused by gradients of giant compressive stresses. The morphology of the multiaxial stress distributions with local concentrations up to −16.5 GPa correlate well with the observed fracture modes. The crack growth is influenced decisively by the film microstructure, especially by the micro- and nano-scopic interfaces. This novel experimental approach offers the capability to interpret indentation response and indenter imprint morphology of small graded nanostructured features. PMID:26947558

In-situ Observation of Cross-Sectional Microstructural Changes and Stress Distributions in Fracturing TiN Thin Film during Nanoindentation.

PubMed

Zeilinger, Angelika; Todt, Juraj; Krywka, Christina; Müller, Martin; Ecker, Werner; Sartory, Bernhard; Meindlhumer, Michael; Stefenelli, Mario; Daniel, Rostislav; Mitterer, Christian; Keckes, Jozef

2016-03-07

Load-displacement curves measured during indentation experiments on thin films depend on non-homogeneous intrinsic film microstructure and residual stress gradients as well as on their changes during indenter penetration into the material. To date, microstructural changes and local stress concentrations resulting in plastic deformation and fracture were quantified exclusively using numerical models which suffer from poor knowledge of size dependent material properties and the unknown intrinsic gradients. Here, we report the first in-situ characterization of microstructural changes and multi-axial stress distributions in a wedge-indented 9 μm thick nanocrystalline TiN film volume performed using synchrotron cross-sectional X-ray nanodiffraction. During the indentation, needle-like TiN crystallites are tilted up to 15 degrees away from the indenter axis in the imprint area and strongly anisotropic diffraction peak broadening indicates strain variation within the X-ray nanoprobe caused by gradients of giant compressive stresses. The morphology of the multiaxial stress distributions with local concentrations up to -16.5 GPa correlate well with the observed fracture modes. The crack growth is influenced decisively by the film microstructure, especially by the micro- and nano-scopic interfaces. This novel experimental approach offers the capability to interpret indentation response and indenter imprint morphology of small graded nanostructured features.

Structure, electronic properties, and oxygen incorporation/diffusion characteristics of the Σ 5 TiN(310)[001] tilt grain boundary

NASA Astrophysics Data System (ADS)

McKenna, Keith P.

2018-02-01

First principles calculations are employed to investigate the structure, electronic properties, and oxygen incorporation/diffusion characteristics of the Σ 5 TiN(310) tilt grain boundary with relevance to applications of polycrystalline TiN in microelectronics and protective coatings. We show that the grain boundary does not significantly modify electronic states near the Fermi energy but does induce an upward shift of up to 0.6 eV in a number of deeper occupied bands. We also show that oxygen is preferentially incorporated into the TiN grain boundary (GB) but must overcome relatively high activation energies for further diffusion. These predictions are consistent with the "stuffed barrier model" proposed to explain the good barrier characteristics of TiN. We also show that while the oxidizing power of TiN GBs is not sufficient to reduce HfO2 (a prototypical gate dielectric material), they can act as a scavenger for interstitial oxygen. Altogether, these results provide the much needed atomistic insights into the properties of a model GB in TiN and suggest a number of directions for future investigation.

The influence of temperature and humidity on printed wiring board surface finishes: Immersion tin vs organic azoles

NASA Astrophysics Data System (ADS)

Ray, U.; Artaki, I.; Gordon, H. M.; Vianco, P. T.

1994-08-01

Substitution of lead-free solders in electronic assemblies requires changes in the conventional Sn:Pb finishes on substrates and component leads to prevent contamination of the candidate lead-free solder. Options for solderability preservative coatings on the printed wiring board include organic (azole or rosin/resin based) films and tin-based plated metallic coatings. This paper compares the solderability performance and corrosion protection effectiveness of electroless tin coatings vs organic azole films after exposure to a series of humidity and thermal cycling conditions. The solderability of immersion tin is directly related to the tin oxide growth on the surface and is not affected by the formation of SnCu intermetallic phases as long as the intermetallic phase is underneath a protective Sn layer. Thin azole films decompose upon heating in the presence of oxygen and lead to solderability degradation. Evaluations of lead-free solder pastes for surface mount assembly applications indicate that immersion tin significantly improves the spreading of Sn:Ag and Sn:Bi alloys as compared to azole surface finishes.

Upgrading tantalum and niobium oxides content in Bangka tin slag with double leaching

NASA Astrophysics Data System (ADS)

Soedarsono, J. W.; Permana, S.; Hutauruk, J. K.; Adhyputra, R.; Rustandi, A.; Maksum, A.; Widana, K. S.; Trinopiawan, K.; Anggraini, M.

2018-03-01

Tantalum has become one of the 14 types of critical materials where the level of its availability is assumed as the midterm critical metal. Benefits of the element tantalum in the electronics field increased the deficit balance of supply / demand, as more variations of electronic products developed. The tantalum experts calculated the level of availability until 2020. Base on the previous studies, tin slag is a secondary source of tantalum and niobium. This study uses tin slag from Bangka, Indonesia, abbreviated, Bangka Tin Slag (BTS). BTS was roasted, water quenched and sieved, abbreviated BTS-RQS.BTS was roasted, water quenched and sieved, abbreviated BTS-RQS.BTS-RQS was roasted at a temperature 700□C given sample code BTS-R700QS, while roasted at 800°C given sample code BTS-R800QS.A variable leaching experiment on BTS-R700QS was solvent concentration variable and on BTS-R800QS was time variable. The entire residue was characterized by X-Ray Fluorescence (XRF), and the optimum results are on the BTS-R800QS leaching into 5 M NaOH for 20 min followed by 5M HCl for 50 min, with content of Ta2O5 and Nb2O51.56% and 1.11%, respectively. The result of XRF measurement showed was the increasing of TNO content due to the increasing solvent concentration and time of acid leaching. The discussion of thermodynamics this study used was HSC Chemistry 6 as a supporting data.

Reactivation of a Tin-Oxide-Containing Catalyst

NASA Technical Reports Server (NTRS)

Hess, Robert; Sidney, Barry; Schryer, David; Miller, Irvin; Miller, George; Upchurch, Bill; Davis, Patricia; Brown, Kenneth

2010-01-01

The electrons in electric-discharge CO2 lasers cause dissociation of some CO2 into O2 and CO, and attach themselves to electronegative molecules such as O2, forming negative O2 ions, as well as larger negative ion clusters by collisions with CO or other molecules. The decrease in CO2 concentration due to dissociation into CO and O2 will reduce the average repetitively pulsed or continuous wave laser power, even if no disruptive negative ion instabilities occur. Accordingly, it is the primary object of this invention to extend the lifetime of a catalyst used to combine the CO and O2 products formed in a laser discharge. A promising low-temperature catalyst for combining CO and O2 is platinum on tin oxide (Pt/SnO2). First, the catalyst is pretreated by a standard procedure. The pretreatment is considered complete when no measurable quantity of CO2 is given off by the catalyst. After this standard pretreatment, the catalyst is ready for its low-temperature use in the sealed, high-energy, pulsed CO2 laser. However, after about 3,000 minutes of operation, the activity of the catalyst begins to slowly diminish. When the catalyst experiences diminished activity during exposure to the circulating gas stream inside or external to the laser, the heated zone surrounding the catalyst is raised to a temperature between 100 and 400 C. A temperature of 225 C was experimentally found to provide an adequate temperature for reactivation. During this period, the catalyst is still exposed to the circulating gas inside or external to the laser. This constant heating and exposing the catalyst to the laser gas mixture is maintained for an hour. After heating and exposing for an appropriate amount of time, the heated zone around the catalyst is allowed to return to the nominal operating temperature of the CO2 laser. This temperature normally resides in the range of 23 to 100 C. Catalyst activity can be measured as the percentage conversion of CO to CO2. In the specific embodiment

Advantages of indium-tin oxide-coated glass slides in correlative scanning electron microscopy applications of uncoated cultured cells.

PubMed

Pluk, H; Stokes, D J; Lich, B; Wieringa, B; Fransen, J

2009-03-01

A method of direct visualization by correlative scanning electron microscopy (SEM) and fluorescence light microscopy of cell structures of tissue cultured cells grown on conductive glass slides is described. We show that by growing cells on indium-tin oxide (ITO)-coated glass slides, secondary electron (SE) and backscatter electron (BSE) images of uncoated cells can be obtained in high-vacuum SEM without charging artefacts. Interestingly, we observed that BSE imaging is influenced by both accelerating voltage and ITO coating thickness. By combining SE and BSE imaging with fluorescence light microscopy imaging, we were able to reveal detailed features of actin cytoskeletal and mitochondrial structures in mouse embryonic fibroblasts. We propose that the application of ITO glass as a substrate for cell culture can easily be extended and offers new opportunities for correlative light and electron microscopy studies of adherently growing cells.

Melting of isolated tin nanoparticles

PubMed

Bachels; Guntherodt; Schafer

2000-08-07

The melting of isolated neutral tin cluster distributions with mean sizes of about 500 atoms has been investigated in a molecular beam experiment by calorimetrically measuring the clusters' formation energies as a function of their internal temperature. For this purpose the possibility to adjust the temperature of the clusters' internal degrees of freedom by means of the temperature of the cluster source's nozzle was exploited. The melting point of the investigated tin clusters was found to be lowered by 125 K and the latent heat of fusion per atom is reduced by 35% compared to bulk tin. The melting behavior of the isolated tin clusters is discussed with respect to the occurrence of surface premelting.

Application of micro- and nanocrystalline cellulose

NASA Astrophysics Data System (ADS)

Sotnikova, Yu S.; Demina, T. S.; Istomin, A. V.; Goncharuk, G. P.; Grandfils, Ch; Akopova, T. A.; Zelenetskii, A. N.; Babayevsky, P. G.

2018-04-01

Micro- and nanocrystalline forms of cellulose were extracted from flax stalks and evaluated in terms of their applicability for various materials science tasks. It was revealed that both form of cellulose had anisometric morphology with length of 27.1 μm and 159 nm; diameter of 8.7 μm and 85 nm, respectively. They were used as reinforcing fillers for fabrication of composite films based on hydroxyethylcellulose. Film-forming and mechanical properties of the composite materials were significantly varied in dependence on filler content (0–10 wt.%) and size. As a second option of micro- and nanocrystalline cellulose application, a study of their effectiveness as stabilizing agents for oil/water Pickering emulsions was carried out. In contrast to micron-sized cellulose the nanocrystalline form appeared to be successful in the process of CH2Cl2/water interface stabilization and fabrication of polylactide microparticles via oil/water Pickering emulsion solvent evaporation technique.

48 CFR 204.7202-3 - TINs.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false TINs. 204.7202-3 Section... OF DEFENSE GENERAL ADMINISTRATIVE MATTERS Contractor Identification 204.7202-3 TINs. Requirements for use of TINs are in FAR subpart 4.9. [64 FR 43100, Aug. 9, 1999] ...

48 CFR 204.7202-3 - TINs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false TINs. 204.7202-3 Section... OF DEFENSE GENERAL ADMINISTRATIVE MATTERS Contractor Identification 204.7202-3 TINs. Requirements for use of TINs are in FAR subpart 4.9. [64 FR 43100, Aug. 9, 1999] ...

48 CFR 204.7202-3 - TINs.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false TINs. 204.7202-3 Section... OF DEFENSE GENERAL ADMINISTRATIVE MATTERS Contractor Identification 204.7202-3 TINs. Requirements for use of TINs are in FAR subpart 4.9. [64 FR 43100, Aug. 9, 1999] ...

48 CFR 204.7202-3 - TINs.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false TINs. 204.7202-3 Section... OF DEFENSE GENERAL ADMINISTRATIVE MATTERS Contractor Identification 204.7202-3 TINs. Requirements for use of TINs are in FAR subpart 4.9. [64 FR 43100, Aug. 9, 1999] ...

48 CFR 204.7202-3 - TINs.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false TINs. 204.7202-3 Section... OF DEFENSE GENERAL ADMINISTRATIVE MATTERS Contractor Identification 204.7202-3 TINs. Requirements for use of TINs are in FAR subpart 4.9. [64 FR 43100, Aug. 9, 1999] ...

Carrier mobility enhancement of nano-crystalline semiconductor films: Incorporation of redox -relay species into the grain boundary interface

NASA Astrophysics Data System (ADS)

Desilva, L. A.; Bandara, T. M. W. J.; Hettiarachchi, B. H.; Kumara, G. R. A.; Perera, A. G. U.; Rajapaksa, R. M. G.; Tennakone, K.

Dye-sensitized and perovskite solar cells and other nanostructured heterojunction electronic devices require securing intimate electronic contact between nanostructured surfaces. Generally, the strategy is solution phase coating of a hole -collector over a nano-crystalline high-band gap n-type oxide semiconductor film painted with a thin layer of the light harvesting material. The nano-crystallites of the hole - collector fills the pores of the painted oxide surface. Most ills of these devices are associated with imperfect contact and high resistance of the hole conducting layer constituted of nano-crystallites. Denaturing of the delicate light harvesting material forbid sintering at elevated temperatures to reduce the grain boundary resistance. It is found that the interfacial and grain boundary resistance can be significantly reduced via incorporation of redox species into the interfaces to form ultra-thin layers. Suitable redox moieties, preferably bonded to the surface, act as electron transfer relays greatly reducing the film resistance offerring a promising method of enhancing the effective hole mobility of nano-crystalline hole-collectors and developing hole conductor paints for application in nanostructured devices.

Investigations of Nanocrystalline Alloy Electrospark Coating Made of Nanocrystalline Alloy Based on 5БДCP Ferrum

NASA Astrophysics Data System (ADS)

Kolomeichenko, A. V.; Kuznetsov, I. S.; Izmaylov, A. Yu; Solovyev, R. Yu; Sharifullin, S. N.

2017-09-01

The article describes the properties of wear resistant electrospark coating made of nanocrystalline alloy of type 5БДCP (Finemet). It is proved that electrospark coating has nanocrystalline structure which is like amorphous matrix with nanocrystals α - Fe. Coating thickness is 33 μm, micro-hardness is 8461 - 11357 MPa, wear resistance is 0,55×104s/g. Coating ofnanocrystalline alloy of type 5БДCP can be used to increase wear resistance of machinery working surfaces.

Dynamics of a pulsed laser generated tin plasma expanding in an oxygen atmosphere

NASA Astrophysics Data System (ADS)

Barreca, F.; Fazio, E.; Neri, F.; Barletta, E.; Trusso, S.; Fazio, B.

2005-10-01

Semiconducting tin oxide can be successfully deposited by means of the laser ablation technique. In particular by ablating metallic tin in a controlled oxygen atmosphere, thin films of SnOx have been deposited. The partial oxygen pressure at which the films are deposited strongly influences both the stoichiometry and the structural properties of the films. In this work, we present a study of the expansion dynamics of the plasma generated by ablating a tin target by means of a pulsed laser using time and space resolved optical emission spectroscopy and fast photography imaging of the expanding plasma. Both Sn I and Sn II optical emission lines have been observed from the time-integrated spectroscopy. Time resolved-measurements revealed the dynamics of the expanding plasma in the ambient oxygen atmosphere. Stoichiometry of the films has been determined by means of X-ray photoelectron spectroscopy and correlated to the expansion dynamics of the plasma.

Nanocrystalline diamond sensor targeted for selective CRP detection: an ATR-FTIR spectroscopy study.

PubMed

Andersson, Per Ola; Viberg, Pernilla; Forsberg, Pontus; Nikolajeff, Fredrik; Österlund, Lars; Karlsson, Mikael

2016-05-01

Protein immobilization on functionalized fluorine-terminated nanocrystalline (NCD) films was studied by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy using an immobilization protocol developed to specifically bind C-reactive protein (CRP). Using an ATR-FTIR spectroscopy method employing a force-controlled anvil-type configuration, three critical steps of the ex situ CRP immobilization were analyzed. First, the NCD surface was passivated by deposition of a copolymer layer consisting of polyethylene oxide and polypropylene oxide. Second, a synthetic modified polypeptide binder with high affinity to CRP was covalently attached to the polymeric film. Third, CRP dissolved in aqueous buffer in concentrations of 10-20 μg/mL was added on the functionalized NCD surface. Both the amide I and II bands, due to the polypeptide binder and CRP, were clearly observed in ATR-FTIR spectra. CRP amide I bands were extracted from difference spectra and yielded bands that agreed well with the reported amide I band of free (non-bonded) CRP in solution. Thus, our results show that CRP retains its secondary structure when it is attached to the polypeptide binders. Compared to previous IR studies of CRP in solution, about 200 times lower concentration was applied in the present study. Graphical Abstract Direct non-destructive ATR-FTIR analysis of C-reactive protein (CRP) selectively bound to functionalized nanocrystalline diamond (NCD) sensor surface.

Characterization of Nanocrystalline Aluminum Alloy 5083 Powders Produced by Cryogenic Attrition

DTIC Science & Technology

2014-11-01

Characterization of Nanocrystalline Aluminum Alloy 5083 Powders Produced by Cryogenic Attrition by Tiffany Ngo ARL-TN-0643...November 2014 Characterization of Nanocrystalline Aluminum Alloy 5083 Powders Produced by Cryogenic Attrition Tiffany Ngo Weapons and...3. DATES COVERED (From - To) August 2014 4. TITLE AND SUBTITLE Characterization of Nanocrystalline Aluminum Alloy 5083 Powders Produced by

Nanocrystalline cellulose from coir fiber: preparation, properties, and applications

USDA-ARS?s Scientific Manuscript database

Nanocrystalline cellulose derived from various botanical sources offers unique and potentially useful characteristics. In principle, any cellulosic material can be considered as a potential source of a nanocrystalline material, including crops, crop residues, and agroindustrial wastes. Because of t...

Potential of nanocrystalline cellulose-fibrin nanocomposites for artificial vascular graft applications

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

Brown, Elvie; Hu, Dehong; Abu-Lail, Nehal

2013-02-19

Nanocrystalline cellulose, a new bio-nanomaterial is utilized as a reinforcing material for biocompatible fibrin matrix to form into a nanocomposite for small-diameter replacement vascular graft application (SDRVG). The periodate oxidation of NCC, which provided it with a reactive carbonyl group, allowed molecular interaction between NCC and fibrin. Such interaction resulted into an effective mechanical reinforcement indicated by the improvement of max. force, elongation at break and modulus when oxidized NCC (ONCC) was incorporated into fibrin. The nanocomposite’s mechanical properties can be manipulated to conform to the native blood vessel by varying the ONCC to fibrin ratio and/or by controlling themore » degree of oxidation of NCC. Using atomic force microscopy had provided fundamental information on the effects of molecular interactions to the nanolevel mechanical properties of NCC/fibrin nanocomposites. This fundamental information established the positive feasibility and commenced continuing investigation for the practical SDRVG application of NCC/fibrin nanocomposite.« less

Nanocrystalline (U0.5Ce0.5)O2±x solid solutions through citrate gel-combustion

NASA Astrophysics Data System (ADS)

Maji, D.; Ananthasivan, K.; Venkata Krishnan, R.; Balakrishnan, S.; Amirthapandian, S.; Joseph, Kitheri; Dasgupta, Arup

2018-04-01

Nanocrystalline powders of (U0.5Ce0.5)O2±x solid solutions were synthesized in bulk (100-200 g) through the citrate gel combustion. The fuel (citric acid) to oxidant (nitrate) mole ratio (R) was varied from 0.1 to 1.0. Two independent lots of the products obtained through the gel-combustion were calcined at 973 K in air and in a mixture of argon containing 8% H2 respectively. All these powders were characterized for their bulk density, X-ray crystallite size, specific surface area, size distribution of the particles, porosity as well as residual carbon. The morphology and microstructures of these powders were studied by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) respectively. Nanocrystalline single phase fluorite solid solutions having a typical crystallite size of about (7-15 nm) were obtained. These powders were highly porous comprising cuboidal flaky agglomerates. The combustion mixture with an 'R' value of 0.25 was found to undergo volume combustion and was found to yield a product that was distinctly different. The systematic investigation on synthesis and characterization of nanocrystalline UCeO2 is reported for the first time.

In situ synthesis of ultra-fine, porous, tin oxide-carbon nanocomposites via a molten salt method for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Liu, Bin; Guo, Zai Ping; Du, Guodong; Nuli, Yanna; Hassan, Mohd Faiz; Jia, Dianzeng

Ultra-fine, porous, tin oxide-carbon (SnO 2/C) nanocomposites are fabricated by a molten salt method at 300 °C, and malic acid is decomposed as the carbon source. In situ synthesis is favourable for the combination of carbon and SnO 2. The structure and morphology are confirmed by X-ray diffraction analysis, specific surface-area measurements, and transmission electron microscopy (TEM). Examination of TEM images reveals that the SnO 2 nanoparticles are embedded in the carbon matrix, with sizes between 2 and 5 nm. The electrochemical measurements show that the nanocomposite delivers a high capacity with good capacity retention as an anode material for lithium-ion batteries, due to the combination of the ultra-fine porous structure and the carbon component.

Method for producing nanocrystalline multicomponent and multiphase materials

DOEpatents

Eastman, Jeffrey A.; Rittner, Mindy N.; Youngdahl, Carl J.; Weertman, Julia R.

1998-01-01

A process for producing multi-component and multiphase nanophase materials is provided wherein a plurality of elements are vaporized in a controlled atmosphere, so as to facilitate thorough mixing, and then condensing and consolidating the elements. The invention also provides for a multicomponent and multiphase nanocrystalline material of specified elemental and phase composition having component grain sizes of between approximately 1 nm and 100 nm. This material is a single element in combination with a binary compound. In more specific embodiments, the single element in this material can be a transition metal element, a non-transition metal element, a semiconductor, or a semi-metal, and the binary compound in this material can be an intermetallic, an oxide, a nitride, a hydride, a chloride, or other compound.

Multilayer (TiN, TiAlN) ceramic coatings for nuclear fuel cladding

NASA Astrophysics Data System (ADS)

Alat, Ece; Motta, Arthur T.; Comstock, Robert J.; Partezana, Jonna M.; Wolfe, Douglas E.

2016-09-01

In an attempt to develop an accident-tolerant fuel (ATF) that can delay the deleterious consequences of loss-of-coolant-accidents (LOCA), multilayer coatings were deposited onto ZIRLO® coupon substrates by cathodic arc physical vapor deposition (CA-PVD). Coatings were composed of alternating TiN (top) and Ti1-xAlxN (2-layer, 4-layer, 8-layer and 16-layer) layers. The minimum TiN top coating thickness and coating architecture were optimized for good corrosion and oxidation resistance. Corrosion tests were performed in static pure water at 360 °C and 18.7 MPa for up to 90 days. The optimized coatings showed no spallation/delamination and had a maximum of 6 mg/dm2 weight gain, which is 6 times smaller than that of a control sample of uncoated ZIRLO® which showed a weight gain of 40.2 mg/dm2. The optimized architecture features a ∼1 μm TiN top layer to prevent boehmite phase formation during corrosion and a TiN/TiAlN 8-layer architecture which provides the best corrosion performance.

Mechanochemical stabilization and sintering of nanocrystalline the (ZrO2)0.97 (Y2O3)0.03 solid solution from pure oxides

NASA Astrophysics Data System (ADS)

Rendtorff, N. M.; Suárez, G.; Sakka, Y.; Aglietti, E. F.

2011-10-01

The mechanochemical activation processing has proved to be an effective technique to enhance a solid-state reaction at relatively low temperatures. In such a process, the mechanical effects of milling, such as reduction of particle size and mixture homogenization, are accompanied by chemical effects, such as partial decomposition of salts or hydroxides resulting in very active reactants. The objective of the present work is to obtain (ZrO2)0.97(Y2O3)0.03 nanocrystalline tetragonal solid solution powders directly using a high energy milling on a mixture of the pure oxides. A second objective is to evaluate the efficiency of the processing proposed and to characterize both textural and structural evolution of the mixtures during the milling processes and throughout posterior low temperature treatments. The Textural and structural evolution were studied by XRD analysis, specific area measurements (BET) and SEM. Firstly a decrease of the crystallinity of the reactants was observed, followed by the disappearance of Y2O3 diffraction peaks and the partial appearance of the tetragonal phase at room temperature. The solid solution proportion was increased with the high energy milling time, obtaining complete stabilization of the tetragonal solid solution with long milling treatments (60 min).The obtained powders were uniaxially pressed and sintered at different temperatures (600-1400°C) the influence of the milling time was correlated with the sinterization degree and final crystalline composition of the materials. Finally, fully stabilized nanocrystalline zirconia materials were obtained satisfactorily by the proposed method.

Achieving high carrier mobility exceeding 70 cm2/Vs in amorphous zinc tin oxide thin-film transistors

NASA Astrophysics Data System (ADS)

Kim, Sang Tae; Shin, Yeonwoo; Yun, Pil Sang; Bae, Jong Uk; Chung, In Jae; Jeong, Jae Kyeong

2017-09-01

This paper proposes a new defect engineering concept for low-cost In- and Ga-free zinc tin oxide (ZTO) thin-film transistors (TFTs). This concept is comprised of capping ZTO films with tantalum (Ta) and a subsequent modest thermal annealing treatment at 200 °C. The Ta-capped ZTO TFTs exhibited a remarkably high carrier mobility of 70.8 cm2/Vs, low subthreshold gate swing of 0.18 V/decade, threshold voltage of -1.3 V, and excellent ION/OFF ratio of 2 × 108. The improvement (> two-fold) in the carrier mobility compared to the uncapped ZTO TFT can be attributed to the effective reduction of the number of adverse tailing trap states, such as hydroxyl groups or oxygen interstitial defects, which stems from the scavenging effect of the Ta capping layer on the ZTO channel layer. Furthermore, the Ta-capped ZTO TFTs showed excellent positive and negative gate bias stress stabilities. [Figure not available: see fulltext.

Indium-tin-oxide-free tris(8-hydroxyquinoline) Al organic light-emitting diodes with 80% enhanced power efficiency

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

Cai, Min; Xiao, Teng; Liu, Rui

2011-10-11

Efficient indium tin oxide (ITO)-free small molecule organic light-emitting diodes (SMOLEDs) with multilayered highly conductive poly(3,4-ethylenedioxy thiophene):poly(styrenesulfonate) (PEDOT:PSS) as the anode are demonstrated. PEDOT:PSS/MoO{sub 3}/N,N'-diphenyl- N,N'-bis(1-naphthylphenyl)-1,1'-biphenyl-4,4'-diamine (NPD)/tris(8-hydroxyquinoline) Al (Alq{sub 3})/4,7-diphenyl-1,10-phenanthroline (BPhen)/LiF/Al SMOLEDs exhibited a peak power efficiency of 3.82 lm/W, 81% higher than that of similar ITO-based SMOLEDs (2.11 lm/W). The improved performance is believed to be due to the higher work function, lower refractive index, and decreased surface roughness of PEDOT:PSS vs ITO, and to Ohmic hole injection from PEDOT:PSS to the NPD layer via the MoO{sub 3} interlayer. The results demonstrate that PEDOT:PSS can substitute ITO in SMOLEDsmore » with strongly improved device performance.« less

Write once read many memory device from Tris-8 (-hydroxyquinoline) aluminum and Indium tin oxide nano particles

NASA Astrophysics Data System (ADS)

Aneesh, J.; Predeep, P.

2011-10-01

Consequent to the fast increase in data storage requirements new materials and device structures are explored in a war footing. Organic memory devices are attracting lot of interest among the researchers and are becoming a hot topic of investigations. This study is an attempt to develop a tri-layer organic memory device using indium tin oxide (ITO) nanoparticles as charge trapping middle layer between tris-8(-hydroxyquinoline)aluminum (Alq3) layers employing spin coating technique. Device switching is studied by applying a current-voltage (I-V) sweep. On increasing the applied bias the device switched from the initial high resistance (OFF) state to a low resistance (ON) state at a switch on voltage of around 4 V. ON/OFF ratio is of the order of 100 at a read voltage of 2 V. The device is found to remain in the low resistance state on further scans, showing the applicability of this device as a write once read many times (WORM) memory.

Room-temperature processed tin oxide thin film as effective hole blocking layer for planar perovskite solar cells