Feasibility of solar-pumped dye lasers

NASA Technical Reports Server (NTRS)

Lee, Ja H.; Kim, Kyung C.; Kim, Kyong H.

1987-01-01

Dye laser gains were measured at various pump-beam irradiances on a dye cell in order to evaluate the feasibility of solar pumping. Rhodamine 6G dye was considered as a candidate for the solar-pumped laser because of its high utilization of the solar spectrum and high quantum efficiency. Measurements show that a solar concentration of 20,000 is required to reach the threshold of the dye.

Metal-free organic dyes for TiO2 and ZnO dye-sensitized solar cells

PubMed Central

Selopal, Gurpreet Singh; Wu, Hui-Ping; Lu, Jianfeng; Chang, Yu-Cheng; Wang, Mingkui; Vomiero, Alberto; Concina, Isabella; Diau, Eric Wei-Guang

2016-01-01

We report the synthesis and characterization of new metal-free organic dyes (namely B18, BTD-R, and CPTD-R) which designed with D-π-A concept to extending the light absorption region by strong conjugation group of π-linker part and applied as light harvester in dye sensitized solar cells (DSSCs). We compared the photovoltaic performance of these dyes in two different photoanodes: a standard TiO2 mesoporous photoanode and a ZnO photoanode composed of hierarchically assembled nanostructures. The results demonstrated that B18 dye has better photovoltaic properties compared to other two dyes (BTD-R and CPTD-R) and each dye has higher current density (Jsc) when applied to hierarchical ZnO nanocrystallites than the standard TiO2 mesoporous film. Transient photocurrent and photovoltage decay measurements (TCD/TVD) were applied to systematically study the charge transport and recombination kinetics in these devices, showing the electron life time (τR) of B18 dye in ZnO and TiO2 based DSSCs is higher than CPTD-R and BTD-R based DSSCs, which is consistent with the photovoltaic performances. The conversion efficiency in ZnO based DSSCs can be further boosted by 35%, when a compact ZnO blocking layer (BL) is applied to inhibit electron back reaction. PMID:26738698

Performance enhancement of dye-sensitized solar cells (DSSCs) using a natural sensitizer

NASA Astrophysics Data System (ADS)

Arifin, Zainal; Soeparman, Sudjito; Widhiyanuriyawan, Denny; Sutanto, Bayu; Suyitno

2017-01-01

Dye-sensitized solar cells (DSSCs) based on natural sensitizers have become a topic of significant research because of their urgency and importance in the energy conversion field and the following advantages: ease of fabrication, low-cost solar cell, and usage of nontoxic materials. The natural sensitizer in DSSCs is responsible for the absorption of light as well as the injection of charges to the conduction band of the semiconductor such as TiO2 nanoparticles. In this study, the chlorophyll extracted from papaya leaves was used as a natural sensitizer. Dye molecules were adsorbed by TiO2 nanoparticle surfaces when submerged in the dye solution for 24 h. The concentration of the dye solution influences both the amount of dye loading and the DSSC performance. The amount of adsorbed dye molecules by TiO2 nanoparticle was calculated using a desorption method. As the concentration of dye solution was increased, the dye loading capacity and power conversion efficiency increased. Above 90 mM dye solution concentration, however, the DSSC efficiency decreased because dye precipitated on the TiO2 nanostructure. These characteristics of DSSCs were analyzed under the irradiation of 100 mW/cm2. The best performance of DSSCs was obtained at 90 mM dye solution, with the values of Voc, Jsc, FF, and efficiency of DSSCs being 0.561 V, 0.402 mA/cm2, 41.65%, and 0.094%, respectively.

Graphene-based copper oxide thin film nanostructures as high-efficiency photocathode for p-type dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Kilic, Bayram; Turkdogan, Sunay; Astam, Aykut; Baran, Sümeyra Seniha; Asgin, Mansur; Cebeci, Hulya; Urk, Deniz

2017-10-01

Graphene-based p-type dye-sensitized solar cells (p-DSSCs) have been proposed and fabricated using copper oxide urchin-like nanostructures (COUN) as photocathode with an FeS2 counter electrode (CE). COUN composed of Cu2O core sphere and CuO shell nanorods with overall diameters of 2 to 4 μm were grown by a simple hydrothermal method with self-assemble nucleation. It was figured out that the formation of copper oxide core/shell structures could be adjusted by an ammonia additive leading to pH change of the precursor solution. In addition to a photocathode, we also demonstrated FeS2 thin films as an efficient CE material alternative to the conventional Pt CEs in DSSCs. FeS2 nanostructures, with diameters of 50 to 80 nm, were synthesized by a similar hydrothermal approach. FeS2 nanostructures are demonstrated to be an outstanding CE material in p-DSSCs. We report graphene/COUN as photocathode and Pt/FeS2 as CE in p-DSSCs, and results show that the synergetic combination of electrodes in each side (increased interconnectivity between COUN and graphene layer, high surface area, and high catalytic activity of FeS2) increased the power conversion efficiency from 1.56% to 3.14%. The excellent performances of COUN and FeS2 thin film in working and CEs, respectively, make them unique choices among the various photocathode and CE materials studied.

Influence of niobium doping in hierarchically organized titania nanostructure on performance of dye-sensitized solar cells.

PubMed

Park, Jong Hoon; Noh, Jun Hong; Han, Byung Suh; Shin, Seong Sik; Park, Ik Jae; Kim, Dong Hoe; Hong, Kug Sun

2012-06-01

Niobium doped hierarchically organized TiO2 nanostructures composed of 20 nm size anatase nanocrystals were synthesized using pulsed laser deposition (PLD). The Nb doping concentration could be facilely controlled by adjusting the concentration of Nb in target materials. We could investigate the influence of Nb doping in the TiO2 photoelectrode on the cell performance of dye-sensitized solar cells (DSSCs) by the exclusion of morphological effects using the prepared Nb-doped TiO2 anostructures. We found no significant change in short circuit current density (Jsc) as a function of Nb doping concentration. However, open circuit voltage (Voc) and fill factor (FF) monotonously decrease with increasing Nb concentration. Dark current characteristics of the DSSCs reveal that the decrease in Voc and FF is attributed to the decrease in shunt resistance due to the increase in conductivity TiO2 by Nb doping. However, electrochemical impedance spectra (EIS) analysis at open circuit condition under illumination showed that the resistance at the TiO2/dye/electrolyte interface increases with Nb concentration, revealing that Nb doping suppress the charge recombination at the interface. In addition, electron life time obtained using characteristic frequency in Bode plot increases from 14 msec to 56 msec with increasing Nb concentration from 0 to 1.2 at%. This implies that the improved light harvesting can be achieved by increasing diffusion length through Nb-doping in the conventional TiO2 photoelectrode.

Efficient dye-sensitized solar cells from mesoporous zinc oxide nanostructures sensitized by N719 dye

NASA Astrophysics Data System (ADS)

Kumara, G. R. A.; Deshapriya, U.; Ranasinghe, C. S. K.; Jayaweera, E. N.; Rajapakse, R. M. G.

2018-03-01

Dye-sensitized solar cells (DSCs) have attracted a great deal of attention due to their low-cost and high power conversion efficiencies. They usually utilize an interconnected nanoparticle layer of TiO2 as the electron transport medium. From the fundamental point of view, faster mobility of electrons in ZnO is expected to contribute to better performance in DSCs than TiO2, though the actual practical situation is quite the opposite. In this research, we addressed this problem by first applying a dense layer of ZnO on FTO followed by a mesoporous layer of interconnected ZnO nanoparticle layer, both were prepared by spray pyrolysis technique. The best cell shows a power conversion efficiency of 5.2% when the mesoporous layer thickness is 14 μm and the concentration of the N719 dye in dye coating solution is 0.3 mM, while a cell without a dense layer shows 4.2% under identical conditions. The surface concentration of dye adsorbed in the cell with a dense layer and that without a dense layer are 5.00 × 10‑7 and 3.34 × 10‑7 mol/cm2, respectively. The cell with the dense layer has an electron lifetime of 54.81 ms whereas that without the dense layer is 11.08 ms. As such, the presence of the dense layer improves DSC characteristics of ZnO-based DSCs.

The dye-sensitized solar cell database.

PubMed

Venkatraman, Vishwesh; Raju, Rajesh; Oikonomopoulos, Solon P; Alsberg, Bjørn K

2018-04-03

Dye-sensitized solar cells (DSSCs) have garnered a lot of attention in recent years. The solar energy to power conversion efficiency of a DSSC is influenced by various components of the cell such as the dye, electrolyte, electrodes and additives among others leading to varying experimental configurations. A large number of metal-based and metal-free dye sensitizers have now been reported and tools using such data to indicate new directions for design and development are on the rise. DSSCDB, the first of its kind dye-sensitized solar cell database, aims to provide users with up-to-date information from publications on the molecular structures of the dyes, experimental details and reported measurements (efficiencies and spectral properties) and thereby facilitate a comprehensive and critical evaluation of the data. Currently, the DSSCDB contains over 4000 experimental observations spanning multiple dye classes such as triphenylamines, carbazoles, coumarins, phenothiazines, ruthenium and porphyrins. The DSSCDB offers a web-based, comprehensive source of property data for dye sensitized solar cells. Access to the database is available through the following URL: www.dyedb.com .

Significant enhancement of power conversion efficiency for dye sensitized solar cell using 1D/3D network nanostructures as photoanodes

PubMed Central

Wang, Hao; Wang, Baoyuan; Yu, Jichao; Hu, Yunxia; Xia, Chen; Zhang, Jun; Liu, Rong

2015-01-01

The single–crystalline TiO2 nanorod arrays with rutile phase have attracted much attention in the dye sensitized solar cells (DSSCs) applications because of their superior chemical stability, better electron transport properties, higher refractive index and low production cost. However, it suffers from a low surface area as compared with TiO2 nanoparticle films. In order to enlarge the surface area of TiO2 nanorod arrays, the 1D nanorods/3D nanotubes sample was synthesized using a facile two-step hydrothermal process involving hydrothermal growth 1D/3D nanorods and followed by post-etching treatment. In such bi-layer structure, the oriented TiO2 nanorods layer could provide direct pathway for fast electron transportation, and the 3D nanotubes layer offers a higher surface area for dye loading, therefore, the 1D nanorods/3D nanotubes photoanode exhibited faster electron transport and higher surface area than either 1D or 3D nanostructures alone, and an highest efficiency of 7.68% was achieved for the DSSCs based on 1D nanorods/3D nanotubes photoanode with further TiCl4 treatment. PMID:25800933

Screen-Printing of ZnO Nanostructures from Sol-Gel Solutions for Their Application in Dye-Sensitized Solar Cells.

PubMed

Sarkar, Kuhu; Braden, Erik V; Bonke, Shannon A; Bach, Udo; Müller-Buschbaum, Peter

2015-08-24

Diblock copolymers have been used in sol-gel synthesis to successfully tailor the nanoscale morphology of thin ZnO films. As the fabrication of several-micron-thick mesoporous films such as those required in dye-sensitized solar cells (DSSCs) was difficult with this approach, we exploited the benefits of diblock-copolymer-directed synthesis that made it compatible with screen printing. The simple conversion of the diblock copolymer ZnO precursor sol to a screen-printing paste was not possible as it resulted in poor film properties. To overcome this problem, an alternative route is proposed in which the diblock copolymer ZnO precursor sol is first blade coated and calcined, then converted to a screen-printing paste. This allows the benefits of diblock-copolymer-directed particle formation to be compatible with printing methods. The morphologies of the ZnO nanostructures were studied by SEM and correlated with the current density-voltage characteristics. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improved electron transfer and plasmonic effect in dye-sensitized solar cells with bi-functional Nb-doped TiO2/Ag ternary nanostructures.

PubMed

Park, Jung Tae; Chi, Won Seok; Jeon, Harim; Kim, Jong Hak

2014-03-07

TiO2 nanoparticles are surface-modified via atom transfer radical polymerization (ATRP) with a hydrophilic poly(oxyethylene)methacrylate (POEM), which can coordinate to the Ag precursor, i.e. silver trifluoromethanesulfonate (AgCF3SO3). Following the reduction of Ag ions, a Nb2O5 doping process and calcination at 450 °C, bi-functional Nb-doped TiO2/Ag ternary nanostructures are generated. The resulting nanostructures are characterized by energy-filtering transmission electron microscopy (EF-TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-visible spectroscopy. The dye-sensitized solar cell (DSSC) based on the Nb-doped TiO2/Ag nanostructure photoanode with a polymerized ionic liquid (PIL) as the solid polymer electrolyte shows an overall energy conversion efficiency (η) of 6.9%, which is much higher than those of neat TiO2 (4.7%) and Nb-doped TiO2 (5.4%). The enhancement of η is mostly due to the increase of current density, attributed to the improved electron transfer properties including electron injection, collection, and plasmonic effects without the negative effects of charge recombination or problems with corrosion. These properties are supported by intensity modulated photocurrent/voltage spectroscopy (IMPS/IMVS) and incident photon-to-electron conversion efficiency (IPCE) measurements.

Dye ingredients and energy conversion efficiency at natural dye sensitized solar cells

NASA Astrophysics Data System (ADS)

Özbay Karakuş, Mücella; Koca, İrfan; Er, Orhan; Çetin, Hidayet

2017-04-01

In this work, natural dyes extracted from the same genus but different species flowers were used as sensitizer in Dye Sensitized Solar Cell (DSSC). To clearly show dye ingredients effect on electrical characteristics, the same genus flowers were selected. The dye ingredients were analyzed by Gas Chromatography Mass Spectrometer (GC-MS). The dyes were modified by a procedure that includes refluxing in acetone. All results indicate a relationship between gallic acid quantity in dyes and solar cell efficiency. To gain further insight, the solar cell parameters were obtained by using the single-diode and double-diode models and they were compared to each other. It was observed that the applied process causes a decrease in series resistance. How the modification process and gallic acid affect energy conversion efficiency were argued in detail in the frame of results that were obtained from solar cell models.

Characteristics of dye Rhoeo spathacea in dye sensitizer solar cell (DSSC)

NASA Astrophysics Data System (ADS)

Sumardiasih, Sri; Obina, Wilfrida M.; Cari; Supriyanto, Agus; Septiawan, Trio Y.; Khairuddin

2017-01-01

Dye-sensitized solar cell (DSSC) is a device that converts solar energy into electrical energy. The magnitude of the efficiency of DSSC is mainly based on the amount of dye absorbed by the surface of TiO2. In this work, used natural dye extracted from leaves Rhoeo spathacea. The dye partially used to immerse of TiO2 as working electrodes, and the rest are directly mixed TiO2 paste to obtain dye titanium dioxide.The paste TiO2 and dye titanium dioxide coated onto the fluorine-doped tin oxide (FTO) glass plate by spin coating method. The absorbance spectra of the dye, dye titanium dioxide and TiO2 were obtained by UV-Vis spectroscopy. The conductivity of the dye, dye titanium dioxide, and TiO2 was measured by two point probe El-Kahfi 100. The DSSC based on dye titanium dioxide that stirring for 5 hours the highest efficiency of 0,0520 % whereas those based on TiO2 immersed for 36 hours showed achieved 0,0501 % obtained from I-V characterization.

Characterising dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Tobin, Laura L.; O'Reilly, Thomas; Zerulla, Dominic; Sheridan, John T.

2009-08-01

With growing energy and environmental concerns due to fossil fuel depletion and global warming there is an increasing attention being attracted by alternative and/or renewable sources of power such as biomass, hydropower, geothermal, wind and solar energy. In today's society there is a vast and in many cases not fully appreciated dependence on electrical power for everyday life and therefore devices such as PV cells are of enormous importance. The more widely used and commercially available silicon (semiconductor) based cells currently have the greatest efficiencies, however the manufacturing of these cells is complex and costly due to the cost and difficulty of producing and processing pure silicon. One new direction being explored is the development of dye-sensitised solar cells (DSSC). The SFI Strategic Research Centre for Solar Energy Conversion is a new research cluster based in Ireland, formed with the express intention of bringing together industry and academia to produce renewable energy solutions. Our specific area of research is in biomimetic dye sensitised solar cells and their electrical properties. We are currently working to develop test equipment, and optoelectronic models describing the performance and behaviors of dye-sensitised solar cells (Grätzel Cells). In this paper we describe some of the background to our work and also some of our initial experimental results. Based on these results we intend to characterise the opto-electrical properties and bulk characteristics of simple dye-sensitised solar cells and then to proceed to test new cell compositions.

Threshold pump power of a solar-pumped dye laser

NASA Technical Reports Server (NTRS)

Lee, Ja H.; Kim, Kyung C.; Kim, Kyong H.

1988-01-01

Threshold solar power for dye laser pumping has been determined by measuring the gain of a rhodamine 6G dye laser amplifier at various solar-simulated irradiances on an amplifier cell. The measured threshold was 20,000 solar constants (2.7 kW/sq cm) for the dye volume of 2 x 5 x 40 cu mm and the optimum dye concentration of 0.001 M. The threshold is about one-third of that achievable with a high-intensity solar concentrator.

Synergistically Enhanced Performance of Ultrathin Nanostructured Silicon Solar Cells Embedded in Plasmonically Assisted, Multispectral Luminescent Waveguides.

PubMed

Lee, Sung-Min; Dhar, Purnim; Chen, Huandong; Montenegro, Angelo; Liaw, Lauren; Kang, Dongseok; Gai, Boju; Benderskii, Alexander V; Yoon, Jongseung

2017-04-25

Ultrathin silicon solar cells fabricated by anisotropic wet chemical etching of single-crystalline wafer materials represent an attractive materials platform that could provide many advantages for realizing high-performance, low-cost photovoltaics. However, their intrinsically limited photovoltaic performance arising from insufficient absorption of low-energy photons demands careful design of light management to maximize the efficiency and preserve the cost-effectiveness of solar cells. Herein we present an integrated flexible solar module of ultrathin, nanostructured silicon solar cells capable of simultaneously exploiting spectral upconversion and downshifting in conjunction with multispectral luminescent waveguides and a nanostructured plasmonic reflector to compensate for their weak optical absorption and enhance their performance. The 8 μm-thick silicon solar cells incorporating a hexagonally periodic nanostructured surface relief are surface-embedded in layered multispectral luminescent media containing organic dyes and NaYF 4 :Yb 3+ ,Er 3+ nanocrystals as downshifting and upconverting luminophores, respectively, via printing-enabled deterministic materials assembly. The ultrathin nanostructured silicon microcells in the composite luminescent waveguide exhibit strongly augmented photocurrent (∼40.1 mA/cm 2 ) and energy conversion efficiency (∼12.8%) than devices with only a single type of luminescent species, owing to the synergistic contributions from optical downshifting, plasmonically enhanced upconversion, and waveguided photon flux for optical concentration, where the short-circuit current density increased by ∼13.6 mA/cm 2 compared with microcells in a nonluminescent medium on a plain silver reflector under a confined illumination.

Synergistically Enhanced Performance of Ultrathin Nanostructured Silicon Solar Cells Embedded in Plasmonically Assisted, Multispectral Luminescent Waveguides

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

Lee, Sung-Min; Dhar, Purnim; Chen, Huandong

Ultrathin silicon solar cells fabricated by anisotropic wet chemical etching of single-crystalline wafer materials represent an attractive materials platform that could provide many advantages for realizing high-performance, low-cost photovoltaics. However, their intrinsically limited photovoltaic performance arising from insufficient absorption of low-energy photons demands careful design of light management to maximize the efficiency and preserve the cost-effectiveness of solar cells. Herein we present an integrated flexible solar module of ultrathin, nanostructured silicon solar cells capable of simultaneously exploiting spectral upconversion and downshifting in conjunction with multispectral luminescent waveguides and a nanostructured plasmonic reflector to compensate for their weak optical absorption andmore » enhance their performance. The 8 μm-thick silicon solar cells incorporating a hexagonally periodic nanostructured surface relief are surface-embedded in layered multispectral luminescent media containing organic dyes and NaYF4:Yb3+,Er3+ nanocrystals as downshifting and upconverting luminophores, respectively, via printing-enabled deterministic materials assembly. The ultrathin nanostructured silicon microcells in the composite luminescent waveguide exhibit strongly augmented photocurrent (~40.1 mA/cm2) and energy conversion efficiency (~12.8%) than devices with only a single type of luminescent species, owing to the synergistic contributions from optical downshifting, plasmonically enhanced upconversion, and waveguided photon flux for optical concentration, where the short-circuit current density increased by ~13.6 mA/cm2 compared with microcells in a nonluminescent medium on a plain silver reflector under a confined illumination.« less

Our Expedition in Linear Neutral Platinum-Acetylide Complexes: The Preparation of Micro/nanostructure Materials, Complicated Topologies, and Dye-Sensitized Solar Cells.

PubMed

Xu, Lin; Yang, Hai-Bo

2016-06-01

During the past few decades, the construction of various kinds of platinum-acetylide complexes has attracted considerable attention, because of their wide applications in photovoltaic cells, non-linear optics, and bio-imaging materials. Among these platinum-acetylide complexes, the linear neutral platinum-acetylide complexes, due to their attractive properties, such as well-defined linear geometry, synthetic accessibility, and intriguing photoproperties, have emerged as a rising star in this field. In this personal account, we will discuss how we entered the field of linear neutral platinum-acetylide chemistry and what we found in this field. The preparation of various types of linear neutral platinum-acetylide complexes and their applications in the areas of micro/nanostructure materials, complicated topologies, and dye-sensitized solar cells will be summarized in this account. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Branched nanostructured anodes for dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Alayashi, Wissal

The high relative efficiency demonstrated in dye-sensitized solar cells (DSSCs) arises from a combination of light scattering within, and photo-generated electron transport through, the porous structure of a TiO2 anodes. However, the convoluted conduction path for extracting photo-generated electrons through the sponge-like structure of conventional DSSC anodes has limited further improvement. This thesis is an investigation of thin film deposited TiO2 anodes with branched tree-like structures that mimic the highly-efficient natural flow structures of trees, rivers, and the human vascular system, which can providing uninterrupted paths for photo-generated electron transport through the hierarchical branches. The main goal has been the development of a robust fabrication process for the study of DSSCs with anodes deposited with glancing angle deposition (GLAD) as it is a new area of research and the first DSSCs produced in our lab. The anodes are deposited as thin films using electron-beam evaporation with two different source of material: metallic Ti and TiO2. Ti films are shown to exhibit highly branched characteristics, with distinct branches when deposited at rate of 15 A/s versus 5 A/s (i.e. rate dependence). A thermal oxidation study for these films is performed using H2/ O2 at 450°C-520°C. For TiO2 films, post deposition annealing is performed in O2 at 450°C. Two methods are explored to create defined active areas of the films: dilute hydrofluoric acid (HF) wet etching, and lift-off lithography. DSSCs are constructed using standard components (N719 dye, I-/I3- electrolyte, and Pt cathode) paired with the photoanodes. The films are characterized by scanning electron microscopy (SEM) and x-ray diffraction (XRD). The properties of DSSCs are investigated with current density-voltage measurements (J-V). Annealed TiO2 films with thickness ranging from 1 microm-3.3 microm exhibit power conversion efficiency of DSSC of 0.5% -3.7%, respectively, which are high

Supersensitization of CdS quantum dots with a near-infrared organic dye: toward the design of panchromatic hybrid-sensitized solar cells.

PubMed

Choi, Hyunbong; Nicolaescu, Roxana; Paek, Sanghyun; Ko, Jaejung; Kamat, Prashant V

2011-11-22

The photoresponse of quantum dot solar cells (QDSCs) has been successfully extended to the near-IR (NIR) region by sensitizing nanostructured TiO(2)-CdS films with a squaraine dye (JK-216). CdS nanoparticles anchored on mesoscopic TiO(2) films obtained by successive ionic layer adsorption and reaction (SILAR) exhibit limited absorption below 500 nm with a net power conversion efficiency of ~1% when employed as a photoanode in QDSC. By depositing a thin barrier layer of Al(2)O(3), the TiO(2)-CdS films were further modified with a NIR absorbing squaraine dye. Quantum dot sensitized solar cells supersensitized with a squariand dye (JK-216) showed good stability during illumination with standard global AM 1.5 solar conditions, delivering a maximum overall power conversion efficiency (η) of 3.14%. Transient absorption and pulse radiolysis measurements provide further insight into the excited state interactions of squaraine dye with SiO(2), TiO(2), and TiO(2)/CdS/Al(2)O(3) films and interfacial electron transfer processes. The synergy of combining semiconductor quantum dots and NIR absorbing dye provides new opportunities to harvest photons from different regions of the solar spectrum. © 2011 American Chemical Society

Dye- and quantum dot-sensitized solar cells based on nanostructured wide-bandgap semiconductors via an integrated experimental and modeling study

NASA Astrophysics Data System (ADS)

Xin, Xukai

Dye-sensitized solar cells (DSSCs) and quantum dot-sensitized solar cells (QDSSCs) are two promising alternative, cost-effective concepts for solar-to-electric energy conversion that have been offered to challenge conventional Si solar cells over the past decade. The configuration of a DSSC or a QDSSC consists of sintered TiO2 nanoparticle films, ruthenium-based dyes or quantum dots (QDs) (i.e., sensitizers), and electrolytes. Upon the absorption of photons, the dyes or QDs generate excitons (i.e., electron-hole pairs). Subsequently, the electrons inject into the TiO2 photoanode to generate photocurrent; scavenged by a redox couple, holes transport to the cathode. The overall power conversion efficiency (PCE) of a DSSC or QDSSC is dictated by the light harvest efficiency, quantum yield for charge injection, and charge collection efficiency at the electrodes. The goal of our research is to understand the fundamental physics and performance of DSSCs and QDSSCs with improved PCE at the low cost based on rational engineering of TiO2 nanostructures, sensitizers, and electrodes through an integrated experimental and modeling study. In this presentation, I will discuss three aspects that I have accomplished over the last several years. (1) Effects of surface treatment and structural modification of photoanode on the performance of DSSCs. First, our research indicates that the surface treatment with both TiCl4 and oxygen plasma yields the most efficient dye-sensitized TiO2-nanoparticle solar cells. A maximum PCE is achieved with a 21 microm thick TiO2 film; the PCE further increases to 8.35% after TiCl4 and O 2 plasma treatments, compared to the untreated TiO2 ( PCE = 3.86%). Second, we used a layer of TiO2 nanoparticle film coated on the FTO glass, and a bilayer of TiO2nanoparticle/freestanding TiO2 nanotube film deposited on the FTO glass as photoanodes. The J˜V parameter analysis acquired by equivalent circuit model simulation reveals that nanotubular structures are

Rapid Dye Regeneration Mechanism of Dye-Sensitized Solar Cells.

PubMed

Jeon, Jiwon; Park, Young Choon; Han, Sang Soo; Goddard, William A; Lee, Yoon Sup; Kim, Hyungjun

2014-12-18

During the light-harvesting process of dye-sensitized solar cells (DSSCs), the hole localized on the dye after the charge separation yields an oxidized dye, D(+). The fast regeneration of D(+) using the redox pair (typically the I(-)/I3(-) couple) is critical for the efficient DSSCs. However, the kinetic processes of dye regeneration remain uncertain, still promoting vigorous debates. Here, we use molecular dynamics simulations to determine that the inner-sphere electron-transfer pathway provides a rapid dye regeneration route of ∼4 ps, where penetration of I(-) next to D(+) enables an immediate electron transfer, forming a kinetic barrier. This explains the recently reported ultrafast dye regeneration rate of a few picoseconds determined experimentally. We expect that our MD based comprehensive understanding of the dye regeneration mechanism will provide a helpful guideline in designing TiO2-dye-electrolyte interfacial systems for better performing DSSCs.

Electropolymerization of Uniform Polyaniline Nanorod Arrays on Conducting Oxides as Counter Electrodes in Dye-Sensitized Solar Cells.

PubMed

He, Ziming; Liu, Jing; Khoo, Si Yun; Tan, Timothy Thatt Yang

2016-01-01

Conventional techniques for the synthesis of oriented polyaniline (PANI) nanostructures are often complex or time consuming. Through an innovative reduced graphene oxide (rGO) modified FTO and a low-potential electropolymerization strategy, the rapid and template-free growth of a highly ordered PANI nanorod array on the FTO substrate is realized. The highly ordered nanostructure of the PANI array leads to a high electrocatalytic activity and chemical stability. The importance of the polymerization potential and rGO surface modification to achieve this nanostructure is revealed. Compared to platinum, the PANI nanorod array exhibits an enhanced performance and stability as counter electrodes in dye-sensitized solar cells, with a 17.6 % enhancement in power conversion efficiency. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Facile synthesis of one dimensional ZnO nanostructures for DSSC applications

NASA Astrophysics Data System (ADS)

Marimuthu, T.; Anandhan, N.

2016-05-01

Development of zinc oxide (ZnO) nanostructure based third generation dye sensitized solar cell is interesting compared to conventional silicon solar cells. ZnO nanostructured thin films were electrochemically deposited onto fluorine doped tin oxide (FTO) glass substrate. The effect of ethylene-diamine-tetra-acetic acid (EDTA) on structural, morphological and optical properties is investigated using X-ray diffraction (XRD) meter, field emission scanning electron microscope (FE-SEM) and micro Raman spectroscopy. XRD patterns reveal that the prepared nanostructures are hexagonal wutrzite structures with (101) plane orientation, the nanostructure prepared using EDTA exhibits better crystallinity. FE-SEM images illustrate that the morphological changes are observed from nanorod structure to cauliflower like structure as EDTA is added. Micro Raman spectra predict that cauliflower like structure possesses a higher crystalline nature with less atomic defects compared to nanorod structures. Dye sensitized solar cell (DSSC) is constructed for the optimized cauliflower structure, and open circuit voltage, short circuit density, fill factor and efficiency are estimated from the J-V curve.

Reactively sputtered nickel nitride as electrocatalytic counter electrode for dye- and quantum dot-sensitized solar cells

NASA Astrophysics Data System (ADS)

Soo Kang, Jin; Park, Min-Ah; Kim, Jae-Yup; Ha Park, Sun; Young Chung, Dong; Yu, Seung-Ho; Kim, Jin; Park, Jongwoo; Choi, Jung-Woo; Jae Lee, Kyung; Jeong, Juwon; Jae Ko, Min; Ahn, Kwang-Soon; Sung, Yung-Eun

2015-05-01

Nickel nitride electrodes were prepared by reactive sputtering of nickel under a N2 atmosphere at room temperature for application in mesoscopic dye- or quantum dot- sensitized solar cells. This facile and reliable method led to the formation of a Ni2N film with a cauliflower-like nanostructure and tetrahedral crystal lattice. The prepared nickel nitride electrodes exhibited an excellent chemical stability toward both iodide and polysulfide redox electrolytes. Compared to conventional Pt electrodes, the nickel nitride electrodes showed an inferior electrocatalytic activity for the iodide redox electrolyte; however, it displayed a considerably superior electrocatalytic activity for the polysulfide redox electrolyte. As a result, compared to dye-sensitized solar cells (DSCs), with a conversion efficiency (η) = 7.62%, and CdSe-based quantum dot-sensitized solar cells (QDSCs, η = 2.01%) employing Pt counter electrodes (CEs), the nickel nitride CEs exhibited a lower conversion efficiency (η = 3.75%) when applied to DSCs, but an enhanced conversion efficiency (η = 2.80%) when applied to CdSe-based QDSCs.

Dendrimer-based Nanoparticle for Dye Sensitized Solar Cells with Improved Efficiency.

PubMed

Ghann, William; Kang, Hyeonggon; Uddin, Jamal; Gonawala, Sunalee J; Mahatabuddin, Sheikh; Ali, Meser M

2018-01-01

Dye sensitized solar cells were fabricated with DyLight680 (DL680) dye and its corresponding europium conjugated dendrimer, DL680-Eu-G5PAMAM, to study the effect of europium on the current and voltage characteristics of the DL680 dye sensitized solar cell. The dye samples were characterized by using Absorption Spectroscopy, Emission Spectroscopy, Fluorescence lifetime and Fourier Transform Infrared measurements. Transmission electron microscopy imaging was carried out on the DL680-Eu-G5PAMAM dye and DL680-Eu-G5PAMAM dye sensitized titanium dioxide nanoparticles to analyze the size of the dye molecules and examine the interaction of the dye with titanium dioxide nanoparticles. The DL680-Eu-G5PAMAM dye sensitized solar cells demonstrated an enhanced solar-to-electric energy conversion of 0.32% under full light illumination (100 mWcm -2 , AM 1.5 Global) in comparison with that of DL680 dye sensitized cells which recorded an average solar-to-electric energy conversion of only 0.19%. The improvement of the efficiency could be due to the presence of the europium that enhances the propensity of dye to absorb sunlight.

Spectroscopic detection of halogen bonding resolves dye regeneration in the dye-sensitized solar cell.

PubMed

Parlane, Fraser G L; Mustoe, Chantal; Kellett, Cameron W; Simon, Sarah J; Swords, Wesley B; Meyer, Gerald J; Kennepohl, Pierre; Berlinguette, Curtis P

2017-11-24

The interactions between a surface-adsorbed dye and a soluble redox-active electrolyte species in the dye-sensitized solar cell has a significant impact on the rate of regeneration of photo-oxidized dye molecules and open-circuit voltage of the device. Dyes must therefore be designed to encourage these interfacial interactions, but experimentally resolving how such weak interactions affect electron transfer is challenging. Herein, we use X-ray absorption spectroscopy to confirm halogen bonding can exist at the dye-electrolyte interface. Using a known series of triphenylamine-based dyes bearing halogen substituents geometrically positioned for reaction with halides in solution, halogen bonding was detected only in cases where brominated and iodinated dyes were photo-oxidized. This result implies that weak intermolecular interactions between photo-oxidized dyes and the electrolyte can impact device photovoltages. This result was unexpected considering the low concentration of oxidized dyes (less than 1 in 100,000) under full solar illumination.

Dye-Sensitized Solar Cells (DSSCs) reengineering using TiO2 with natural dye (anthocyanin)

NASA Astrophysics Data System (ADS)

Subodro, Rohmat; Kristiawan, Budi; Ramelan, Ari Handono; Wahyuningsih, Sayekti; Munawaroh, Hanik; Hanif, Qonita Awliya; Saputri, Liya Nikmatul Maula Zulfa

2017-01-01

This research on Dye-Sensitized Solar Cells (DSSCs) reengineering was carried out using TiO2 with natural dye (anthocyanin). The fabrication of active carbon layer/TiO2 DSSC solar cell was based on natural dye containing anthocyanins such as mangosteen peel, red rose flower, black glutinous rice, and purple eggplant peel. DSSC was prepared with TiO2 thin layer doped with active carbon; Natural dye was analyzed using UV-Vis and TiO2 was analyzed using X-ray diffractometer (XRD), meanwhile scanning electron microscope (SEM) was used to obtain the size of the crystal. Keithley instrument test was carried out to find out I-V characteristics indicating that the highest efficiency occurred in DSSCs solar cell with 24-hour soaking with mangosteen peel 0.00047%.

TiO₂ Nanowire Networks Prepared by Titanium Corrosion and Their Application to Bendable Dye-Sensitized Solar Cells.

PubMed

Jin, Saera; Shin, Eunhye; Hong, Jongin

2017-10-12

TiO₂ nanowire networks were prepared, using the corrosion of Ti foils in alkaline (potassium hydroxide, KOH) solution at different temperatures, and then a further ion-exchange process. The prepared nanostructures were characterized by field emission scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The wet corroded foils were utilized as the photoanodes of bendable dye-sensitized solar cells (DSSCs), which exhibited a power conversion efficiency of 1.11% under back illumination.

Photostability of low cost dye-sensitized solar cells based on natural and synthetic dyes

NASA Astrophysics Data System (ADS)

Abdou, E. M.; Hafez, H. S.; Bakir, E.; Abdel-Mottaleb, M. S. A.

2013-11-01

This paper deals with the use of some natural pigments as well as synthetic dyes to act as sensitizers in dye-sensitized solar cells (DSSCs). Anthocyanin dye extracted from rosella (Hibiscus sabdariffa L.) flowers, the commercially available textile dye Remazole Red RB-133 (RR) and merocyanin-like dye based on 7-methyl coumarin are tested. The photostability of the three dyes is investigated under UV-Vis light exposure. The results show a relatively high stability of the three dyes. Moreover, the photostability of the solid dyes is studied over the TiO2 film electrodes. A very low decolorization rates are recorded as; rate constants k = 1.6, 2.1 and 1.9 × 10-3 min-1 for anthocyanin, RR and coumarin dyes, respectively. The stability results favor selecting anthocyanin as a promising sensitizer candidate in DSSCs based on natural products. Dyes-sensitized solar cells are fabricated and their conversion efficiency (η) is 0.27%, 0.14% and 0.001% for the anthocyanin, RR and coumarin dyes, respectively. Moreover, stability tests of the sealed cells based on anthocyanin and RR dyes are done under continuous light exposure of 100 mW cm-2, reveals highly stable DSSCs.

Self-assembled ultra small ZnO nanocrystals for dye-sensitized solar cell application

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

Patra, Astam K.; Dutta, Arghya; Bhaumik, Asim, E-mail: msab@iacs.res.in

2014-07-01

We demonstrate a facile chemical approach to produce self-assembled ultra-small mesoporous zinc oxide nanocrystals using sodium salicylate (SS) as a template under hydrothermal conditions. These ZnO nanomaterials have been successfully fabricated as a photoanode for the dye-sensitized solar cell (DSSC) in the presence of N719 dye and iodine–triiodide electrolyte. The structural features, crystallinity, purity, mesophase and morphology of the nanostructure ZnO are investigated by several characterization tools. N{sub 2} sorption analysis revealed high surface areas (203 m{sup 2} g{sup −1}) and narrow pore size distributions (5.1–5.4 nm) for different samples. The mesoporous structure and strong photoluminescence facilitates the high dyemore » loading at the mesoscopic void spaces and light harvesting in DSSC. By utilizing this ultra-small ZnO photoelectrode with film thickness of about 7 μm in the DSSC with an open-circuit voltage (V{sub OC}) of 0.74 V, short-circuit current density (J{sub SC}) of 3.83 mA cm{sup −2} and an overall power conversion efficiency of 1.12% has been achieved. - Graphical abstract: Ultra-small ZnO nanocrystals have been synthesized with sodium salicylate as a template and using it as a photoanode in a dye-sensitized solar cell 1.12% power conversion efficiency has been observed. - Highlights: • Synthesis of self-assembled ultra-small mesoporous ZnO nanocrystals by using sodium salicylate as a template. • Mesoporous ZnO materials have high BET surface areas and void space. • ZnO nanoparticles serve as a photoanode for the dye-sensitized solar cell (DSSC). • Using ZnO nanocrystals as photoelectrode power conversion efficiency of 1.12% has been achieved.« less

Performance and stability analysis of curcumin dye as a photo sensitizer used in nanostructured ZnO based DSSC

NASA Astrophysics Data System (ADS)

Sinha, D.; De, D.; Ayaz, A.

2018-03-01

Environmental friendly natural dye curcumin extracted from low-cost Curcumina longa stem is used as a photo-sensitizer for the fabrication of ZnO-based dye-sensitized solar cells (DSSC). Nanostructured ZnO is fabricated on a transparent conducting glass (TCO), using a cost-effective chemical bath deposition technique. Scanning electron microscopic images show hexagonal patterned ZnO nano-towers decorated with several nanosteps. The average length of ZnO nano-tower is 5 μm and diameter is 1.2 μm. The UV-Vis spectroscopic study of the curcumin dye is used to understand the light absorption behavior as well as band gap energy of the extracted natural dye. The dye shows wider absorption band-groups over 350-470 nm and 500-600 nm with two peaks positioned at 425 nm and 525 nm. The optical band gap energy and energy band position of the dye is derived which supports its stability and high electron affinity that makes it suitable for light harvesting and effortless electron transfer from dye to the semiconductor or interface between them. FTIR spectrum of curcumin dye-sensitized ZnO-based DSSC shows the presence of anchoring groups and colouring constitutes. The I-V and P-V curves of the fabricated DSSC are measured under simulated light (100 mW/cm2). The highest visible light to electric conversion efficiency of 0.266% (using ITO) and 0.33% (using FTO) is achieved from the curcumin dye-sensitized cell.

Deliberate Design of TiO2 Nanostructures towards Superior Photovoltaic Cells.

PubMed

Sun, Ziqi; Liao, Ting; Sheng, Liyuan; Kou, Liangzhi; Kim, Jung Ho; Dou, Shi Xue

2016-08-01

TiO2 nanostructures are being sought after as flexibly utilizable building blocks for the fabrication of the mesoporous thin-film photoelectrodes that are the heart of the third-generation photovoltaic devices, such as dye-sensitized solar cells (DSSCs), quantum-dot-sensitized solar cells (QDSSCs), and the recently promoted perovskite-type solar cells. Here, we report deliberate tailoring of TiO2 nanostructures for superior photovoltaic cells. Morphology engineering of TiO2 nanostructures is realized by designing synthetic protocols in which the precursor hydrolysis, crystal growth, and oligomer self-organization are precisely controlled. TiO2 nanostructures in forms varying from isolated nanocubes, nanorods, and cross-linked nanorods to complex hierarchical structures and shape-defined mesoporous micro-/nanostructures were successfully synthesized. The photoanodes made from the shape-defined mesoporous TiO2 microspheres and nanospindles presented superior performances, owing to the well-defined overall shapes and the inner ordered nanochannels, which allow not only a high amount of dye uptake, but also improved visible-light absorption. This study provides a new way to seek an optimal synthetic protocol to meet the required functionality of the nanomaterials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Superior Adsorption and Regenerable Dye Adsorbent Based on Flower-Like Molybdenum Disulfide Nanostructure

NASA Astrophysics Data System (ADS)

Han, Sancan; Liu, Kerui; Hu, Linfeng; Teng, Feng; Yu, Pingping; Zhu, Yufang

2017-03-01

Herein we report superior dye-adsorption performance for flower-like nanostructure composed of two dimensional (2D) MoS2 nanosheets by a facile hydrothermal method, more prominent adsorption of cationic dye compared with anodic dye indicates the dye adsorption performance strongly depends on surface charge of MoS2 nanosheets. The adsorption mechanism of dye is analyzed, the kinetic data of dye adsorption fit well with the pseudo-second-order model, meanwhile adsorption capability at different equilibrium concentrations follows Langmuir model, indicating the favorability and feasibility of dye adsorption. The regenerable property for MoS2 with full adsorption of dye molecules by using alkaline solution were demonstrated, showing the feasibility of reuse for the MoS2, which is promising in its practical water treatment application.

Natural dye extract of lawsonia inermis seed as photo sensitizer for titanium dioxide based dye sensitized solar cells.

PubMed

Ananth, S; Vivek, P; Arumanayagam, T; Murugakoothan, P

2014-07-15

Natural dye extract of lawsonia inermis seed were used as photo sensitizer to fabricate titanium dioxide nanoparticles based dye sensitized solar cells. Pure titanium dioxide (TiO2) nanoparticles in anatase phase were synthesized by sol-gel technique and pre dye treated TiO2 nanoparticles were synthesized using modified sol-gel technique by mixing lawsone pigment rich natural dye during the synthesis itself. This pre dye treatment with natural dye has yielded colored TiO2 nanoparticles with uniform adsorption of natural dye, reduced agglomeration, less dye aggregation and improved morphology. The pure and pre dye treated TiO2 nanoparticles were subjected to structural, optical, spectral and morphological studies. Dye sensitized solar cells (DSSC) fabricated using the pre dye treated and pure TiO2 nanoparticles sensitized by natural dye extract of lawsonia inermis seed showed a promising solar light to electron conversion efficiency of 1.47% and 1% respectively. The pre dye treated TiO2 based DSSC showed an improved efficiency of 47% when compared to that of conventional DSSC. Copyright © 2014 Elsevier B.V. All rights reserved.

Atomic layer deposition in nanostructured photovoltaics: tuning optical, electronic and surface properties

NASA Astrophysics Data System (ADS)

Palmstrom, Axel F.; Santra, Pralay K.; Bent, Stacey F.

2015-07-01

Nanostructured materials offer key advantages for third-generation photovoltaics, such as the ability to achieve high optical absorption together with enhanced charge carrier collection using low cost components. However, the extensive interfacial areas in nanostructured photovoltaic devices can cause high recombination rates and a high density of surface electronic states. In this feature article, we provide a brief review of some nanostructured photovoltaic technologies including dye-sensitized, quantum dot sensitized and colloidal quantum dot solar cells. We then introduce the technique of atomic layer deposition (ALD), which is a vapor phase deposition method using a sequence of self-limiting surface reaction steps to grow thin, uniform and conformal films. We discuss how ALD has established itself as a promising tool for addressing different aspects of nanostructured photovoltaics. Examples include the use of ALD to synthesize absorber materials for both quantum dot and plasmonic solar cells, to grow barrier layers for dye and quantum dot sensitized solar cells, and to infiltrate coatings into colloidal quantum dot solar cell to improve charge carrier mobilities as well as stability. We also provide an example of monolayer surface modification in which adsorbed ligand molecules on quantum dots are used to tune the band structure of colloidal quantum dot solar cells for improved charge collection. Finally, we comment on the present challenges and future outlook of the use of ALD for nanostructured photovoltaics.

Fe-tannic acid complex dye as photo sensitizer for different morphological ZnO based DSSCs

NASA Astrophysics Data System (ADS)

Çakar, Soner; Özacar, Mahmut

2016-06-01

In this paper we have synthesized different morphological ZnO nanostructures via microwave hydrothermal methods at low temperature within a short time. We described different morphologies of ZnO at different Zn(NO3)2/KOH mole ratio. The ZnO nanostructures were characterized via X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and UV-vis spectrophotometry. All ZnO structures have hexagonal wurtzite type structures. The FESEM images showed various morphologies of ZnO such as plate, rod and nanoparticles. Dye sensitized solar cells have been assembled by these different morphological structures photo electrode and tannic acid or Fe-tannic acid complex dye as sensitizer. We have achieved at maximum efficiencies of photovoltaic cells prepared with ZnO plate in all dye systems. The conversion efficiencies of dye sensitized solar cells are 0.37% and 1.00% with tannic acid and Fe-tannic acid complex dye, respectively.

Fabrication and characterization of mixed dye: Natural and synthetic organic dye

NASA Astrophysics Data System (ADS)

Richhariya, Geetam; Kumar, Anil

2018-05-01

Mixed dye from hibiscus sabdariffa and eosin Y was employed in the fabrication of dye sensitized solar cell (DSSC). Nanostructured mesoporous film was prepared from the titanium dioxide (TiO2). The energy conversion efficiency of hibiscus, eosin Y and mixed dye was obtained as 0.41%, 1.53% and 2.02% respectively. Mixed DSSC has shown improvement in the performance of the cell as compared to hibiscus and eosin Y dye due to addition of synthetic organic dye. This illustrates the effect of synthetic organic dyes in performance enhancement of natural dyes. It has been credited to the improved absorption of light mainly in higher energy state (λ = 440-560 nm) when two dyes were employed simultaneously as was obvious from the absorption spectra of dyes adsorbed onto TiO2 electrode. The cell with TiO2 electrode sensitized by mixed dye gives short circuit current density (Jsc) = 4.01 mA/cm2, open circuit voltage (Voc) = 0.67 V, fill factor (FF) = 0.60 and energy conversion efficiency (η) of 2.02%.

Dye-sensitized solar cells based on purple corn sensitizers

NASA Astrophysics Data System (ADS)

Phinjaturus, Kawin; Maiaugree, Wasan; Suriharn, Bhalang; Pimanpaeng, Samuk; Amornkitbamrung, Vittaya; Swatsitang, Ekaphan

2016-09-01

Natural dye extracted from husk, cob and silk of purple corn, were used for the first time as photosensitizers in dye sensitized solar cells (DSSCs). The dye sensitized solar cells fabrication process has been optimized in terms of solvent extraction. The resulting maximal efficiency of 1.06% was obtained from purple corn husk extracted by acetone. The ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and incident photon-to-current efficiency (IPCE) were employed to characterize the natural dye and the DSSCs.

Enhanced photovoltaic performance of dye sensitized solar cell using SnO2 nanoflowers

NASA Astrophysics Data System (ADS)

Arote, Sandeep A.; Tabhane, Vilas A.; Pathan, Habib M.

2018-01-01

The study highlighted enhanced performance of SnO2 based DSSC using photoanode with nanostructured morphology. The simple organic surfactant free hydrothermal synthesis method was used for preparation of SnO2 nanoflowers for dye sensitized solar cell (DSSC) application. The hydrothermal reaction time was varied to obtain different SnO2 nanostructures. The hydrothermal reaction time showed considerable effect on optical and structural properties of the prepared samples. The results indicated that the prepared samples were pure rutile SnO2. The band gap of prepared samples was greater than bulk SnO2 and varied from 3.64 to 3.81 eV with increase in hydrothermal reaction time. With increase in reaction time from 4 to 24 h, the microstructure of SnO2 changed from agglomerated nanoparticles to nanopetals and finally to self-assembled nanoflowers. Flower-like SnO2 nanostructures showed size around 300-700 nm, and composed of large numbers of 3 dimensional petals connected with each other forming 3D nanoflowers by self-assembly. Consequently, the DSSC with flower-like SnO2 nanostructures exhibited good photovoltaic performance with Voc, Jsc and η about 0.43 V, 4.36 mA/cm2 and 1.11%, respectively.

Optimization of nanoparticle structure for improved conversion efficiency of dye solar cell

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

Mohamed, Norani Muti, E-mail: noranimuti-mohamed@petronas.com.my; Zaine, Siti Nur Azella, E-mail: ct.azella@gmail.com.my

2014-10-24

Heavy dye loading and the ability to contain the light within the thin layer (typically ∼12 μm) are the requirement needed for the photoelectrode material in order to enhance the harvesting efficiency of dye solar cell. This can be realized by optimizing the particle size with desirable crystal structure. The paper reports the investigation on the dependency of the dye loading and light scattering on the properties of nanostructured photoelectrode materials by comparing 4 different samples of TiO{sub 2} in the form of nanoparticles and micron-sized TiO{sub 2} aggregates which composed of nanocrystallites. Their properties were evaluated by using scanningmore » electron microscopy, X-ray diffraction and UVVis spectroscopy while the performance of the fabricated test cells were measured using universal photovoltaic test system (UPTS) under 1000 W/cm{sup 2} intensity of radiation. Nano sized particles provide large surface area which allow for greater dye adsorption but have no ability to retain the incident light in the TiO{sub 2} film. In contrast, micron-sized particles in the form of aggregates can generate light scattering allowing the travelling distance of the light to be extended and increasing the interaction between the photons and dye molecules adsorb on TiO{sub 2}nanocrystallites. This resulted in an improvement in the conversion efficiency of the aggregates that demonstrates the close relation between light scattering effect and the structure of the photolectrode film.« less

Light collection optimization for composite photoanode in dye-sensitized solar cells: Towards higher efficiency

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

Guo, X. Z.; Shen, W. Z., E-mail: wzshen@sjtu.edu.cn; Laboratory of Condensed Matter Spectroscopy and Opto-Electronic Physics, and Key Laboratory of Artificial Structures and Quantum Control

2015-06-14

Composite photoanode comprising nanoparticles and one-dimensional (1D) nanostructure is a promising alternative to conventional photoanode for dye-sensitized solar cells (DSCs). Besides fast electron transport channels, the 1D nanostructure also plays as light scattering centers. Here, we theoretically investigate the light scattering properties of capsule-shaped 1D nanostructure and their influence on the light collection of DSCs. It is found that the far-field light scattering of a single capsule depends on its volume, shape, and orientation: capsules with bigger equivalent spherical diameter, smaller aspect ratio, and horizontal orientation demonstrate stronger light scattering especially at large scattering angle. Using Monte Carlo approach, wemore » simulated and optimized the light harvesting efficiency of the cell. Two multilayer composite photoanodes containing orderly or randomly oriented capsules are proposed. DSCs composed of these two photoanodes are promising for higher efficiencies because of their efficient light collection and superior electron collection. These results will provide practical guidance to the design and optimization of the photoanodes for DSCs.« less

Effectiveness of dye sensitised solar cell under low light condition using wide band dye

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

Sahmer, Ahmad Zahrin, E-mail: ahmadzsahmer@gmail.com; Mohamed, Norani Muti, E-mail: noranimuti-mohamed@petronas.com.my; Zaine, Siti Nur Azella, E-mail: ct.azella@gmail.com

2015-07-22

Dye sensistised solar cell (DSC) based on nanocrystalline TiO{sub 2} has the potential to be used in indoor consumer power application. In realizing this, the DSC must be optimized to generate power under low lighting condition and under wider visible light range. The use of wide band dye N749 which has a wider spectrum sensitivity increases the photon conversion to electron between the visible light spectrums of 390nm to 700nm. This paper reports the study on the effectiveness of the dye solar cell with N749 dye under low light condition in generating usable power which can be used for indoormore » consumer application. The DSC was fabricated using fluorine doped tin oxide (FTO) glass with screen printing method and the deposited TiO{sub 2} film was sintered at 500°C. The TiO{sub 2} coated FTO glass was then soaked in the N749 dye, assembled into test cell, and tested under the standard test condition at irradiance of 1000 W/m{sup 2} with AM1.5 solar soaker. The use of the 43T mesh for the dual pass screen printing TiO{sub 2} paste gives a uniform TiO{sub 2} film layer of 16 µm. The low light condition was simulated using 1/3 filtered irradiance with the solar soaker. The fabricated DSC test cell with the N749 dye was found to have a higher efficiency of 6.491% under low light condition compared to the N719 dye. Under the standard test condition at 1 sun the N749 test cell efficiency is 4.55%. The increases in efficiency is attributed to the wider spectral capture of photon of the DSC with N749 dye. Furthermore, the use of N749 dye is more effective under low light condition as the V{sub OC} decrement is less significant compared to the latter.« less

Preparation of Nanoporous TiO2 for Dye-Sensitized Solar Cell (DSSC) Using Various Dyes

NASA Astrophysics Data System (ADS)

Yuliarto, Brian; Fanani, Fahiem; Fuadi, M. Kasyful; Nugraha

2010-10-01

This article reports the development of organic dyes as an attempt to reduce material costs of Dye-Sensitized Solar Cell (DSSC). Indonesia, a country with variety and considerable number of botanical resources, is suitable to perform the research. Indonesian black rice, curcuma, papaya leaf, and the combination were chosen as organic dyes source. Dyes were extracted using organic solvent and adsorbed on mesoporous Titanium Dioxide (TiO2) which has been optimized in our laboratory. The best dyes light absorbance and performance obtained from papaya leaf as chlorophyll dyes that gives two peaks at 432 nm and 664 nm from UV-Vis Spectrophotometry and performance under 100 mW/cm2 Xenon light solar simulator gives VOC = 0.566 Volt, JSC = 0.24 mA/cm2, Fill Factor = 0.33, and efficiency of energy conversion 0,045%.

Progress and Design Concerns of Nanostructured Solar Energy Harvesting Devices.

PubMed

Leung, Siu-Fung; Zhang, Qianpeng; Tavakoli, Mohammad Mahdi; He, Jin; Mo, Xiaoliang; Fan, Zhiyong

2016-05-01

Integrating devices with nanostructures is considered a promising strategy to improve the performance of solar energy harvesting devices such as photovoltaic (PV) devices and photo-electrochemical (PEC) solar water splitting devices. Extensive efforts have been exerted to improve the power conversion efficiencies (PCE) of such devices by utilizing novel nanostructures to revolutionize device structural designs. The thicknesses of light absorber and material consumption can be substantially reduced because of light trapping with nanostructures. Meanwhile, the utilization of nanostructures can also result in more effective carrier collection by shortening the photogenerated carrier collection path length. Nevertheless, performance optimization of nanostructured solar energy harvesting devices requires a rational design of various aspects of the nanostructures, such as their shape, aspect ratio, periodicity, etc. Without this, the utilization of nanostructures can lead to compromised device performance as the incorporation of these structures can result in defects and additional carrier recombination. The design guidelines of solar energy harvesting devices are summarized, including thin film non-uniformity on nanostructures, surface recombination, parasitic absorption, and the importance of uniform distribution of photo-generated carriers. A systematic view of the design concerns will assist better understanding of device physics and benefit the fabrication of high performance devices in the future. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Near-infrared sensitization in dye-sensitized solar cells.

PubMed

Park, Jinhyung; Viscardi, Guido; Barolo, Claudia; Barbero, Nadia

2013-01-01

Dye-sensitized solar cells (DSCs) are a low cost and colorful promising alternative to standard silicon photovoltaic cells. Though many of the highest efficiencies have been associated with sensitizers absorbing only in the visible portion of the solar radiation, there is a growing interest for NIR sensitization. This paper reviews the efforts made so far to find sensitizers able to absorb efficiently in the far-red NIR region of solar light. Panchromatic sensitizers as well as dyes absorbing mainly in the 650-920 nm region have been considered.

Polyaniline Nanofibers as the Hole Transport Medium in an Inverse Dye-Sensitized Solar Cell

NASA Astrophysics Data System (ADS)

Hesselsweet, Ian Brock

In order to become a viable alternative to silicon photovoltaics, dye-sensitized solar cells must overcome several issues primarily resulting from their use of a liquid electrolyte. Much research has gone into correcting these shortcomings by replacing the liquid electrolyte with solid-state hole-transport media. Using these solid-state materials brings new difficulties, such as completely filling the pores in the TiO2 nanostructure, and achieving good adhesion with the dye-coated TiO2. A novel approach to addressing these difficulties is the inverse dye-sensitized solar cell design. In this method the devices are constructed in reverse order, with the solidstate hole-transport medium providing the nanostructure instead of the TiO2. This allows new materials and methods to be used which may better address these issues. In this project, inverse dye-sensitized solar cells using polyaniline nanofibers as the hole transport medium were prepared and characterized. The devices were prepared on fluorine-doped tin oxide (FTO) coated glass electrodes. The first component was a dense spin-coated polyaniline blocking layer, to help prevent short circuiting of the devices. The second layer was a thin film of drop cast polyaniline nanofibers which acted as the hole transport medium and provided high surface area for the dye attachment. The dye used was 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP), which was covalently attached to the nanofibers using a Friedel-Crafts acylation. Titania gel was then deposited into the pores of the nanofiber film by controlled hydrolysis of a titanium complex (Tyzor LA). A back electrode of TiO2 nanoparticles sintered on FTO was pressed on top to complete the devices. A typical device generated an open circuit voltage of 0.17 V and a closed circuit current of 5.7 nA/cm2 while the highest open circuit voltage recorded for any variation on a device was 0.31 V and the highest short circuit current was 52 nA/cm2 under AM 1.5 simulated solar

Dye-sensitized solar cells

DOEpatents

Skotheim, T.A.

1980-03-04

A low-cost dye-sensitized Schottky barrier solar cell is comprised of a substrate of semiconductor with an ohmic contact on one face, a sensitizing dye adsorbed onto the opposite face of the semiconductor, a transparent thin-film layer of a reducing agent over the dye, and a thin-film layer of metal over the reducing agent. The ohmic contact and metal layer constitute electrodes for connection to an external circuit and one or the other or both are made transparent to permit light to penetrate to the dye and be absorbed therein for generating electric current. The semiconductor material chosen to be the substrate is one having a wide bandgap and which therefore is transparent; the dye selected is one having a ground state within the bandgap of the semiconductor to generate carriers in the semiconductor, and a first excited state above the conduction band edge of the semiconductor to readily conduct electrons from the dye to the semiconductor; the reducing agent selected is one having a ground state above the ground state of the sensitizer to provide a plentiful source of electrons to the dye during current generation and thereby enhance the generation; and the metal for the thin-film layer of metal is selected to have a Fermi level in the vicinity of or above the ground state of the reducing agent to thereby amply supply electrons to the reducing agent. 3 figs.

Dye-sensitized solar cells

DOEpatents

Skotheim, Terje A. [Berkeley, CA

1980-03-04

A low-cost dye-sensitized Schottky barrier solar cell comprised of a substrate of semiconductor with an ohmic contact on one face, a sensitizing dye adsorbed onto the opposite face of the semiconductor, a transparent thin-film layer of a reducing agent over the dye, and a thin-film layer of metal over the reducing agent. The ohmic contact and metal layer constitute electrodes for connection to an external circuit and one or the other or both are made transparent to permit light to penetrate to the dye and be absorbed therein for generating electric current. The semiconductor material chosen to be the substrate is one having a wide bandgap and which therefore is transparent; the dye selected is one having a ground state within the bandgap of the semiconductor to generate carriers in the semiconductor, and a first excited state above the conduction band edge of the semiconductor to readily conduct electrons from the dye to the semiconductor; the reducing agent selected is one having a ground state above the ground state of the sensitizer to provide a plentiful source of electrons to the dye during current generation and thereby enhance the generation; and the metal for the thin-film layer of metal is selected to have a Fermi level in the vicinity of or above the ground state of the reducing agent to thereby amply supply electrons to the reducing agent.

Enhanced performances of dye-sensitized solar cells based on Au-TiO2 and Ag-TiO2 plasmonic hybrid nanocomposites

NASA Astrophysics Data System (ADS)

Ran, Huili; Fan, Jiajie; Zhang, Xiaoli; Mao, Jing; Shao, Guosheng

2018-02-01

Novel double-layer films were prepared and applied to dye-sensitized solar cells (DSSCs) using commercial TiO2 nanoparticles as a bonding underlayer and noble metal (Au and Ag) nanoparticles (NP) and nanowires (NW) incorporated to hybrid TiO2 composites, consisting of 3 dimensional (3D) hierarchical microspheres, 3D hollow spheres, 2 dimensional (2D) nanosheets and commercial P25 nanoparticles, as multifunctional light scattering overlayer. The influence of Au NP, Ag NP, Au NW, and Ag NW on of microstructures of the film electrodes and the photovoltaic (PV) performances of DSSCs was investigated. The result revealed that the ranges and intensity of sunlight absorption, the photo capture ability for dye molecules of the hybrid nanocomposite film electrodes, and the photoelectric conversion efficiency (PCE) of the cells were all significantly enhanced due to the plasmonic effect of the noble metal nanostructures. All composite DSSCs with noble metal nanostructures have higher PCE than the pure TiO2 solar cell. This is attributed the improved electron transport of the noble metal nanostructures, and the improvement of light absorption because of their local surface plasmon resonance (LSPR) effect. Under optical conditions, a PCE of 5.74% was obtained in the TiO2-AgNW DSSC, representing a 25.3% enhancement compared to a reference solar cell based on pure TiO2 film (4.58%). The main reason of the advancement is the improved electron transport of AgNW, the light absorption enhancement on account of the LSPR effect of AgNW, and increased light scattering due to the incorporation of the large one dimensional AgNWs within the photo-anode.

Step-by-Step Heating of Dye Solution for Efficient Solar Energy Harvesting in Dye-Sensitized Solar Cells

NASA Astrophysics Data System (ADS)

Shah, Syed Afaq Ali; Sayyad, Muhammad Hassan; Abdulkarim, Salem; Qiao, Qiquan

2018-05-01

A step-by-step heat treatment was applied to ruthenium-based N719 dye solution for its potential application in dye-sensitized solar cells (DSSCs). The effects were analyzed and compared with standard untreated devices. A significant increase in short circuit current density was observed by employing a step-by-step heating method for dye solution in DSSCs. This increase of J sc is attributed to the enhancement in dye adsorption by the surface of the semiconductor and the higher number of charge carriers generated. DSSCs fabricated by a heated dye solution have achieved an overall power conversion efficiency of 8.41% which is significantly higher than the efficiency of 7.31% achieved with DSSCs fabricated without heated dye. Electrochemical impedance spectroscopy and capacitance voltage studies were performed to understand the better performance of the device fabricated with heated dye. Furthermore, transient photocurrent and transient photovoltage measurements were also performed to gain an insight into interfacial charge carrier recombinations.

Effect of dye extracting solvents and sensitization time on photovoltaic performance of natural dye sensitized solar cells

NASA Astrophysics Data System (ADS)

Hossain, Md. Khalid; Pervez, M. Firoz; Mia, M. N. H.; Mortuza, A. A.; Rahaman, M. S.; Karim, M. R.; Islam, Jahid M. M.; Ahmed, Farid; Khan, Mubarak A.

In this study, natural dye sensitizer based solar cells were successfully fabricated and photovoltaic performance was measured. Sensitizer (turmeric) sources, dye extraction process, and photoanode sensitization time of the fabricated cells were analyzed and optimized. Dry turmeric, verdant turmeric, and powder turmeric were used as dye sources. Five distinct types of solvents were used for extraction of natural dye from turmeric. Dyes were characterized by UV-Vis spectrophotometric analysis. The extracted turmeric dye was used as a sensitizer in the dye sensitized solar cell's (DSSC) photoanode assembly. Nano-crystalline TiO2 was used as a film coating semiconductor material of the photoanode. TiO2 films on ITO glass substrate were prepared by simple doctor blade technique. The influence of the different parameters VOC, JSC, power density, FF, and η% on the photovoltaic characteristics of DSSCs was analyzed. The best energy conversion performance was obtained for 2 h adsorption time of dye on TiO2 nano-porous surface with ethanol extracted dye from dry turmeric.

Fabrication of dye-sensitized solar cell using chlorophylls pigment from sargassum

NASA Astrophysics Data System (ADS)

Ridwan, M. A.; Noor, E.; Rusli, M. S.; Akhiruddin

2018-04-01

Dye-sensitized solar cell (DSSC) is a new generation of the solar cell. Its development in the dye-sensitized system is varied. Natural dyes have been the choice in developing DSSC. This study used a dye-sensitized chlorophyll pigment from Sargassum sp. as a dye-sensitized solar cell. This study aims to obtain chlorophyll pigment extract to be used as a dye in DSSC and to obtain the best energy conversion efficiency from DSSC. The chlorophyll pigments were extracted using APHA method (2012), and the TiO2 coating method used was doctor blade method. The two fabricated cells have an area of 1 cm2 immersed with chlorophyll dye for 30 hours. Then these cells were tested using direct sun radiation. The concentration value of chlorophyll in acetone solution was 61.176 mg/L. The efficiency value obtained was 1.50% with VOC of 241 mV, ISC 2.9 x 10-4 mA and fill factor 0.432.

Ionic Liquid Electrolytes for Flexible Dye-Sensitized Solar Cells

DTIC Science & Technology

2014-09-01

High-Efficiency Solar - Cell Based on Dye-Sensitized Colloidal TiO2 Films,” a DSSC consists of four main components: a photoanode, a counter... solar cell modules. 2. Experiment and Calculations 2.1 Materials Commercial TiO2 paste was purchased from Dyesol, and additional nanophase TiO2 ...B.; Grätzel, M. A Low-Cost, High Efficiency Solar Cell Based on Dye_Sensitized Colloidal TiO2 Films. Nature 1991, 353, 737–740. 2. Snaith, H. J

Theoretical Study of Electron Transfer Properties of Squaraine Dyes for Dye Sensitized Solar Cell

NASA Astrophysics Data System (ADS)

Juwita, Ratna; Tsai, Hui-Hsu Gavin

2018-01-01

The environmental issues and high cost of Ru create many scientists to explore cheaper and safer sensitizer as alternative for dye sensitized solar cells (DSCs). Dyes play an important role in solar energy conversion efficiency. The squaraine (SQ) dyes has good spectral match with the solar spectra, therefore, SQ dyes have great potential for the applications in DSCs. SQ01_CA is an unsymmetrical SQ dye, reported by Grätzel and colleagues in 2007, featuring a D-π-spacer-A framework and has a carboxylic acid anchoring group. The electron donating ability of indolium in SQ01_CA and SQ01_CAA dyes is relatively weak, better performance may be achieved by introducing an additional donor moiety into indolium [1]. In this study, we investigate six unsymmetrical SQ dyes adsorbed on a (TiO2)38 cluster [2] using density functional theory (DFT) and time-dependent DFT to study electron transfer properties of squaraine dyes on their photophysical. SQ01_CA, WH-SQ01_CA, and WH-SQ02_CA use a carboxylic acid group as its electron acceptor. Furthermore, SQ01_CAA, WH-SQ01_CAA, and WH-SQ02_CAA use a cyanoacrylic acid group as its electron acceptor. WH-SQ01_CA and WH-SQ01_CAA have an alkyl, while WH-SQ02_CA and WH-SQ02_CAA have alkoxyl substituted diarylamines to the indolium donor of sensitizer SQ01_CA. Our calculations show with additional diarylamines in donor tail of WH-SQ02_CAA, the SQ dyes have red-shifted absorption and have slightly larger probability of electron density transferred to TiO2 moiety. Furthermore, an additional -CN group as electron a withdrawing group in the acceptor exhibits red-shifted absorption and enhances the electron density transferred to TiO2 and anchoring moiety after photo-excitation. The tendency of calculated probabilities of electron density being delocalized into TiO2 and driving force for excited-state electron injection of these studied SQ dyes is compatible with their experimentally observed.

Natural dye extracted from karkadah and its application in dye-sensitized solar cells: experimental and density functional theory study.

PubMed

Reda, S M; Soliman, K A

2016-02-01

This work presents an experimental and theoretical study of cyanidin natural dye as a sensitizer for ZnO dye-sensitized solar cells. ZnO nanoparticles were prepared using ammonia and oxalic acid as a capping agent. The calculated average size of the synthesized ZnO with different capping agents was found to be 32.1 nm. Electronic properties of cyanidin and delphinidin dye were studied using density functional theory (DFT) and time-dependent DFT with a B3LYP/6-31G(d,p) level. By comparing the theoretical results with the experimental data, the cyanidin dye can be used as a sensitizer in dye-sensitized solar cells. An efficiency of 0.006% under an AM-1.5 illumination at 100  mW/cm(2) was attained. The influence of dye adsorption time on the solar cell performance is discussed.

Metal-free organic dyes for dye-sensitized solar cells: from structure: property relationships to design rules.

PubMed

Mishra, Amaresh; Fischer, Markus K R; Bäuerle, Peter

2009-01-01

Dye-sensitized solar cells (DSSC) have attracted considerable attention in recent years as they offer the possibility of low-cost conversion of photovoltaic energy. This Review focuses on recent advances in molecular design and technological aspects of metal-free organic dyes for applications in dye-sensitized solar cells. Special attention has been paid to the design principles of these dyes and on the effect of various electrolyte systems. Cosensitization, an emerging technique to extend the absorption range, is also discussed as a way to improve the performance of the device. In addition, we report on inverted dyes for photocathodes, which constitutes a relatively new approach for the production of tandem cells. Special consideration has been paid to the correlation between the molecular structure and physical properties to their performance in DSSCs.

Enhanced blue responses in nanostructured Si solar cells by shallow doping

NASA Astrophysics Data System (ADS)

Cheon, Sieun; Jeong, Doo Seok; Park, Jong-Keuk; Kim, Won Mok; Lee, Taek Sung; Lee, Heon; Kim, Inho

2018-03-01

Optimally designed Si nanostructures are very effective for light trapping in crystalline silicon (c-Si) solar cells. However, when the lateral feature size of Si nanostructures is comparable to the junction depth of the emitter, dopant diffusion in the lateral direction leads to excessive doping in the nanostructured emitter whereby poor blue responses arise in the external quantum efficiency (EQE). The primary goal of this study is to find the correlation of emitter junction depth and carrier collection efficiency in nanostructured c-Si solar cells in order to enhance the blue responses. We prepared Si nanostructures of nanocone shape by colloidal lithography, with silica beads of 520 nm in diameter, followed by a reactive ion etching process. c-Si solar cells with a standard cell architecture of an Al back surface field were fabricated varying the emitter junction depth. We varied the emitter junction depth by adjusting the doping level from heavy doping to moderate doping to light doping and achieved greatly enhanced blue responses in EQE from 47%-92% at a wavelength of 400 nm. The junction depth analysis by secondary ion mass-spectroscopy profiling and the scanning electron microscopy measurements provided us with the design guide of the doping level depending on the nanostructure feature size for high efficiency nanostructured c-Si solar cells. Optical simulations showed us that Si nanostructures can serve as an optical resonator to amplify the incident light field, which needs to be considered in the design of nanostructured c-Si solar cells.

Design of hybrid nanoheterostructure systems for enhanced quantum and solar conversion efficiencies in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Kılıç, Bayram; Telli, Hakan; Tüzemen, Sebahattin; Başaran, Ali; Pirge, Gursev

2015-04-01

Dye sensitized solar cells (DSSCs) with an innovative design involving controlled-morphology vertically aligned (VA) ZnO nanowires within mesoporous TiO2 structures with ultrahigh surface area for implementation as photoanodes are herein reported. Although TiO2 nanostructures exhibit excellent power conversion efficiency, the electron transport rate is low owing to low electron mobility. To overcome this, ZnO nanowires with high electron mobility have been investigated as potential candidates for photoanodes. However, the power conversion efficiency of ZnO nanowires is still lower than that of TiO2 owing to their low internal surface area. Consequently, in this work, vertical growth of ZnO nanowires within mesoporous TiO2 structures is carried out to increase their solar power conversion efficiency. The photovoltaic performance of solar cells using ZnO nanowires, mesoporous TiO2, and TiO2/ZnO hybrid structures are compared. The VA TiO2/ZnO hybrid structures are found to provide direct electron transfer compared with the tortuous pathway of zero-dimensional nanostructures, resulting in an increased conversion efficiency. It is demonstrated that the light scattering of the photoanode film is increased and electron recombination is decreased when an appropriate amount of mesoporous TiO2 is used as a substrate for ZnO nanowires. The DSSC fabricated with the TiO2/ZnO hybrid photoanode prepared with 15.8 wt. % TiO2 showed the highest conversion efficiency of 7.30%, approximately 5%, 18%, and 40% higher than that of DSSCs fabricated with 3.99 wt. % TiO2, pure TiO2, and pure ZnO photoanodes, respectively.

Coupling of Luminescent Solar Concentrators to Plasmonic Solar Cells

NASA Astrophysics Data System (ADS)

Wang, Shu-Yi

To make inexpensive solar cells is a continuous goal for solar photovoltaic (PV) energy industry. Thin film solar cells of various materials have been developed and continue to emerge in order to replace bulk silicon solar cells. A thin film solar cell not only uses less material but also requires a less expensive refinery process. In addition, other advantages coming along with small thickness are higher open circuit voltage and higher conversion efficiency. However, thin film solar cells, especially those made of silicon, have significant optical losses. In order to address this problem, this thesis investigates the spectral coupling of thin films PV to luminescent solar concentrators (LSC). LSC are passive devices, consisting of plastic sheets embedded with fluorescent dyes which absorb part of the incoming radiation spectrum and emit at specific wavelength. The emitted light is concentrated by total internal reflection to the edge of the sheet, where the PVs are placed. Since the light emitted from the LSC edge is usually in a narrow spectral range, it is possible to employ diverse strategies to enhance PV absorption at the peak of the emission wavelength. Employing plasmonic nanostructures has been shown to enhance absorption of thin films via forward scattering, diffraction and localized surface plasmon. These two strategies are theoretically investigated here for improving the absorption and elevating the output power of a thin film solar cell. First, the idea of spectral coupling of luminescent solar concentrators to plasmonic solar cells is introduced to assess its potential for increasing the power output. This study is carried out employing P3HT/PC60BM organic solar cells and LSC with Lumogen Red dyes. A simplified spectral coupling analysis is employed to predict the power density, considering the output spectrum of the LSC equivalent to the emission spectrum of the dye and neglecting any angular dependence. Plasmonic tuning is conducted to enhance

Interplay between transparency and efficiency in dye sensitized solar cells.

PubMed

Tagliaferro, Roberto; Colonna, Daniele; Brown, Thomas M; Reale, Andrea; Di Carlo, Aldo

2013-02-11

In this paper we analyze the interplay between transparency and efficiency in dye sensitized solar cells by varying fabrication parameters such as the thickness of the nano-crystalline TiO(2) layer, the dye loading and the dye type. Both transparency and efficiency show a saturation trend when plotted versus dye loading. By introducing the transparency-efficiency plot, we show that the relation between transparency and efficiency is linear and is almost independent on the TiO(2) thickness for a certain thickness range. On the contrary, the relation between transparency and efficiency depends strongly on the type of the dye. Moreover, we show that co-sensitization techniques can be effectively used to access regions of the transparency-efficiency space that are forbidden for single dye sensitization. The relation found between transparency and efficiency (T&E) can be the general guide for optimization of Dye Solar Cells in building integration applications.

A Hybrid Tandem Solar Cell Combining a Dye-Sensitized and a Polymer Solar Cell.

PubMed

Shao, Zhipeng; Chen, Shuanghong; Zhang, Xuhui; Zhu, Liangzheng; Ye, Jiajiu; Dai, Songyuan

2016-06-01

A hybrid tandem solar cell was assambled by connecting a dye sensitized solar cell and a polymer solar cell in series. A N719 sensitized TiO2 was used as photocathode in dye-sensitized subcell, and a MEH-PPV/PCBM composite was used as active layer in the polymer subcell. The polymer subcell fabricated on the counter electrode of the dye sensitized solar cell. A solution processed TiO(x) layer was used as electron collection layer of the polymer sub cell and the charge recombination layer. The effects of the TiO(x) interlayer and the spectral overlap between the two sub cells have been studied and optimized. The results shows that a proper thickness of the TiO(x) layer is needed for tandem solar cells. Thick TiO(x) will enhance the series resistance, but too thin TiO(x), layer will damage the hole blocking effect and its hydrophilic. The resulting optimized tandem solar cells exhibited a power conversion efficiency of 1.28% with a V(oc) of 0.95 V under simulated 100 mW cm(-2) AM 1.5 illumination.

Green grasses as light harvesters in dye sensitized solar cells

NASA Astrophysics Data System (ADS)

Shanmugam, Vinoth; Manoharan, Subbaiah; Sharafali, A.; Anandan, Sambandam; Murugan, Ramaswamy

2015-01-01

Chlorophylls, the major pigments presented in plants are responsible for the process of photosynthesis. The working principle of dye sensitized solar cell (DSSC) is analogous to natural photosynthesis in light-harvesting and charge separation. In a similar way, natural dyes extracted from three types of grasses viz. Hierochloe Odorata (HO), Torulinium Odoratum (TO) and Dactyloctenium Aegyptium (DA) were used as light harvesters in dye sensitized solar cells (DSSCs). The UV-Vis absorption spectroscopy, Fourier transform infrared (FT-IR), and liquid chromatography-mass spectrometry (LC-MS) were used to characterize the dyes. The electron transport mechanism and internal resistance of the DSSCs were investigated by the electrochemical impedance spectroscopy (EIS). The performance of the cells fabricated with the grass extract shows comparable efficiencies with the reported natural dyes. Among the three types of grasses, the DSSC fabricated with the dye extracted from Hierochloe Odorata (HO) exhibited the maximum efficiency. LC-MS investigations indicated that the dominant pigment present in HO dye was pheophytin a (Pheo a).

Mesoporous multi-shelled ZnO microspheres for the scattering layer of dye sensitized solar cell with a high efficiency

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

Xia, Weiwei; Mei, Chao; Zeng, Xianghua, E-mail: xhzeng@yzu.edu.cn

2016-03-14

Both light scattering and dye adsorbing are important for the power conversion efficiency PCE performance of dye sensitized solar cell (DSSC). Nanostructured scattering layers with a large specific surface area are regarded as an efficient way to improve the PCE by increasing dye adsorbing, but excess adsorbed dye will hinder light scattering and light penetration. Thus, how to balance the dye adsorbing and light penetration is a key problem to improve the PCE performance. Here, multiple-shelled ZnO microspheres with a mesoporous surface are fabricated by a hydrothermal method and are used as scattering layers on the TiO{sub 2} photoanode ofmore » the DSSC in the presence of N719 dye and iodine–based electrolyte, and the results reveal that the DSSCs based on triple shelled ZnO microsphere with a mesoporous surface exhibit an enhanced PCE of 7.66%, which is 13.0% higher than those without the scattering layers (6.78%), indicating that multiple-shelled microspheres with a mesoporous surface can ensure enough light scattering between the shells, and a favorable concentration of the adsorbed dye can improve the light penetration. These results may provide a promising pathway to obtain the high efficient DSSCs.« less

The TiO2 Hierarchical Structure with Nanosheet Spheres for Improved Photoelectric Performance in Dye-Sensitized Solar Cells

NASA Astrophysics Data System (ADS)

Yin, Xin; Guan, Yingli; Song, Lixin; Xie, Xueyao; Du, Pingfan; Xiong, Jie

2018-04-01

A bi-layer photoanode is successfully fabricated for dye-sensitized solar cells (DSSCs) composed of P25/TiO2 nanorod (P25/TNR) as the underlayer and TiO2 nanosheet spheres (TNSs) as the light-scattering layer. Notably, the P25-TNR provides multiple functions, including more dye loading, more efficient charge transport and a lower electron recombination rate for the photoanode. Besides, the unique structure of TNS can significantly improve the light-harvesting capacity, boosting the light-harvesting efficiency. Therefore, an enhanced short-circuit current and power conversion efficiency of 18.04 mA cm-2 and 5.99%, respectively, were achieved for the P25/TNR-TNS-based DSSC, which was better than that of the P25-TNS-based (15.17 mA cm-2, 5.36%) and bare TNS-based (11.43 mA cm-2, 4.14%) DSSCs. This indicates that this bi-layer structure effectively combines the advantages of the one-dimensional (1D) nanostructure and three-dimensional (3D) hierarchical structure. In short, this work demonstrates the possibility of fabricating desirable photoanodes for high-performance DSSCs by rational design of nanostructures and effective combination of multi-functional components.

Template-free hydrothermal synthesis of beaded nanochain bundles of ZnO and their application as photoanode in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Ballal, Reshma; Shinde, Manish; Waghadkar, Yogesh; Arbuj, Sudhir; Rane, Sunit; Chauhan, Ratna

2018-02-01

ZnO shows promising candidature as photoanode material for dye-sensitized solar cells (DSSCs) due to its high bulk electron mobility and easily tailorable geometrical structures. The objective of this study is to facilitate the development of highly porous hierarchical ZnO for enhanced power conversion efficiency in dye-sensitized solar cells (DSSC) due to its greater dye adsorption. This study investigated the influence of reaction temperatures of 120 °C (sample Z-1) and 180 °C (sample Z-2) in hydrothermal synthesis on structural, morphological and optical properties of resultant ZnO nanostructures and their performance as photoanode material in DSSCs. The synthesized beaded nanochain bundles of ZnO, with multilayered and highly ordered texture, have diameters of several micrometers. Structural and morphological analysis shows that the ZnO beaded nanochain-like architectures possess wurtzite crystalline nature. These morphological improvements (beaded nanochains) of ZnO were found to exhibit higher dye loading and conversion efficiency due to increase in the surface area while reducing charge recombination. The maximum conversion efficiency was obtained with Z-1 and Z-2 is 2.95 and 3.56% with photocurrent of 7.73 and 9.24 mA/cm2, respectively. The obtained results pertaining to the DSSC performance studies were corroborated by the impedance spectroscopy data.

Ionic liquid electrolytes for dye-sensitized solar cells.

PubMed

Gorlov, Mikhail; Kloo, Lars

2008-05-28

The potential of room-temperature molten salts (ionic liquids) as solvents for electrolytes for dye-sensitized solar cells has been investigated during the last decade. The non-volatility, good solvent properties and high electrochemical stability of ionic liquids make them attractive solvents in contrast to volatile organic solvents. Despite this, the relatively high viscosity of ionic liquids leads to mass-transport limitations. Here we review recent developments in the application of different ionic liquids as solvents or components of liquid and quasi-solid electrolytes for dye-sensitized solar cells.

Monolithic-Structured Single-Layered Textile-Based Dye-Sensitized Solar Cells.

PubMed

Yun, Min Ju; Cha, Seung I; Kim, Han Seong; Seo, Seon Hee; Lee, Dong Y

2016-10-06

Textile-structured solar cells are frequently discussed in the literature due to their prospective applications in wearable devices and in building integrated solar cells that utilize their flexibility, mechanical robustness, and aesthetic appearance, but the current approaches for textile-based solar cells-including the preparation of fibre-type solar cells woven into textiles-face several difficulties from high friction and tension during the weaving process. This study proposes a new structural concept and fabrication process for monolithic-structured textile-based dye-sensitized solar cells that are fabricated by a process similar to the cloth-making process, including the preparation of wires and yarns that are woven for use in textiles, printed, dyed, and packaged. The fabricated single-layered textile-based dye-sensitized solar cells successfully act as solar cells in our study, even under bending conditions. By controlling the inter-weft spacing and the number of Ti wires for the photoelectrode conductor, we have found that the performance of this type of dye-sensitized solar cell was notably affected by the spacing between photoelectrodes and counter-electrodes, the exposed areas of Ti wires to photoelectrodes, and photoelectrodes' surface morphology. We believe that this study provides a process and concept for improved textile-based solar cells that can form the basis for further research.

Solar/UV-induced photocatalytic degradation of three commercial textile dyes.

PubMed

Neppolian, B; Choi, H C; Sakthivel, S; Arabindoo, Banumathi; Murugesan, V

2002-01-28

The photocatalytic degradation of three commercial textile dyes with different structure has been investigated using TiO(2) (Degussa P25) photocatalyst in aqueous solution under solar irradiation. Experiments were conducted to optimise various parameters viz. amount of catalyst, concentration of dye, pH and solar light intensity. Degradation of all the dyes were examined by using chemical oxygen demand (COD) method. The degradation efficiency of the three dyes is as follows: Reactive Yellow 17(RY17) > Reactive Red 2(RR2) > Reactive Blue 4 (RB4), respectively. The experimental results indicate that TiO(2) (Degussa P25) is the best catalyst in comparison with other commercial photocatalysts such as, TiO(2) (Merck), ZnO, ZrO(2), WO(3) and CdS. Though the UV irradiation can efficiently degrade the dyes, naturally abundant solar irradiation is also very effective in the mineralisation of dyes. The comparison between thin-film coating and aqueous slurry method reveals that slurry method is more efficient than coating but the problems of leaching and the requirement of separation can be avoided by using coating technique. These observations indicate that all the three dyes could be degraded completely at different time intervals. Hence, it may be a viable technique for the safe disposal of textile wastewater into the water streams.

Fabrication of nanostructured CIGS solar cells

NASA Astrophysics Data System (ADS)

Zhang, Hongwang; Wang, Fang; Parry, James; Perera, Samanthe; Zeng, Hao

2012-02-01

We present the work on Cu(In,Ga)(Se,S)2 based nanostructured solar cells based on nanowire arrays. CIGS as the light absorber for thin-film solar cells has been widely studied recently, due to its high absorption coefficient, long-term stability, and low-cost of fabrication. Recently, solution phase processed CIGS thin film solar cells attracted great attention due to their extremely low fabrication cost. However, the performance is lower than vacuum based thin films possibly due to higher density of defects and lower carrier mobility. On the other hand, one dimensional ordered nanostructures such as nanowires and nanorods can be used to make redial junction solar cells, where the orthogonality between light absorption and charge carrier separation can lead to enhanced PV performance. Since the charge carriers only need to traverse a short distance in the radial direction before they are separated at the heterojunction interface, the radial junction scheme can be more defect tolerant than their planar junction scheme. In this work, a wide band gap nanowire or nanotube array such as TiO2 is used as a scaffold where CIGS is conformally coated using solution phase to obtain a radial heterojunction solar cell. Their performance is compared that of the planar thin film solar cells fabricated with the same materials.

Detection of gain enhancement in laser-induced fluorescence of rhodamine B lasing dye by silicon dioxide nanostructures-coated cavity

NASA Astrophysics Data System (ADS)

Al-Tameemi, Mohammed N. A.

2018-03-01

In this work, nanostructured silicon dioxide films are deposited by closed-field unbalanced direct-current (DC) reactive magnetron sputtering technique on two sides of quartz cells containing rhodamine B dye dissolved in ethanol with 10‒5 M concentration as a random gain medium. The preparation conditions are optimized to prepare highly pure SiO2 nanostructures with a minimum particle size of about 20 nm. The effect of SiO2 films as external cavity for the random gain medium is determined by the laser-induced fluorescence of this medium, and an increase of about 200% in intensity is observed after the deposition of nanostructured SiO2 thin films on two sides of the dye cell.

Dye-Sensitized Solar Cells for Space Power

NASA Technical Reports Server (NTRS)

Harris, Jerry D.; Hehemann, David G.; Duraj, Stan A.

2003-01-01

During the course of this grant, dye-sensitized solar cells were prepared and characterized. The solar cells were prepared using materials (dyes, electrolytes, transparent conductive oxide coated glass, nanocrystalline TiO2) entirely prepared in-house, as well as prepared using materials available commercially. Complete cells were characterized under simulated AM0 illumination. The best cell prepared at NASA had an AM0 efficiency of 1.22% for a 1.1 sq cm cell. Short circuit current (Isc), open circuit voltage (Voc) and fill factor (FF) for the cell were 6.95 mA, 618 mV and 42.8%, respectively. For comparison purposes, two commercially prepared dye-sensitized solar cells were obtained from Solaronix SA, Aubonne, Switzerland. The Solaronix cells were also characterized under simulated AM0 illumination. The best cell from Solaronix had an active area of 3.71 sq cm and measured an AM0 efficiency of 3.16%. with Isc, Voc and FF of 45.80 mA, 669.6 mV and 52.3%, respectively. Both cells from Solaronix were rapid thermal cycled between -80 C and 80 C. Thermal cycling led to a 4.6% loss of efficiency in one of the cells and led to nearly a complete failure in the second cell.

Counter electrodes in dye-sensitized solar cells.

PubMed

Wu, Jihuai; Lan, Zhang; Lin, Jianming; Huang, Miaoliang; Huang, Yunfang; Fan, Leqing; Luo, Genggeng; Lin, Yu; Xie, Yimin; Wei, Yuelin

2017-10-02

Dye-sensitized solar cells (DSSCs) are regarded as prospective solar cells for the next generation of photovoltaic technologies and have become research hotspots in the PV field. The counter electrode, as a crucial component of DSSCs, collects electrons from the external circuit and catalyzes the redox reduction in the electrolyte, which has a significant influence on the photovoltaic performance, long-term stability and cost of the devices. Solar cells, dye-sensitized solar cells, as well as the structure, principle, preparation and characterization of counter electrodes are mentioned in the introduction section. The next six sections discuss the counter electrodes based on transparency and flexibility, metals and alloys, carbon materials, conductive polymers, transition metal compounds, and hybrids, respectively. The special features and performance, advantages and disadvantages, preparation, characterization, mechanisms, important events and development histories of various counter electrodes are presented. In the eighth section, the development of counter electrodes is summarized with an outlook. This article panoramically reviews the counter electrodes in DSSCs, which is of great significance for enhancing the development levels of DSSCs and other photoelectrochemical devices.

Green grasses as light harvesters in dye sensitized solar cells.

PubMed

Shanmugam, Vinoth; Manoharan, Subbaiah; Sharafali, A; Anandan, Sambandam; Murugan, Ramaswamy

2015-01-25

Chlorophylls, the major pigments presented in plants are responsible for the process of photosynthesis. The working principle of dye sensitized solar cell (DSSC) is analogous to natural photosynthesis in light-harvesting and charge separation. In a similar way, natural dyes extracted from three types of grasses viz. Hierochloe Odorata (HO), Torulinium Odoratum (TO) and Dactyloctenium Aegyptium (DA) were used as light harvesters in dye sensitized solar cells (DSSCs). The UV-Vis absorption spectroscopy, Fourier transform infrared (FT-IR), and liquid chromatography-mass spectrometry (LC-MS) were used to characterize the dyes. The electron transport mechanism and internal resistance of the DSSCs were investigated by the electrochemical impedance spectroscopy (EIS). The performance of the cells fabricated with the grass extract shows comparable efficiencies with the reported natural dyes. Among the three types of grasses, the DSSC fabricated with the dye extracted from Hierochloe Odorata (HO) exhibited the maximum efficiency. LC-MS investigations indicated that the dominant pigment present in HO dye was pheophytin a (Pheo a). Copyright © 2014 Elsevier B.V. All rights reserved.

Extension lifetime for dye-sensitized solar cells through multiple dye adsorption/desorption process

NASA Astrophysics Data System (ADS)

Chiang, Yi-Fang; Chen, Ruei-Tang; Shen, Po-Shen; Chen, Peter; Guo, Tzung-Fang

2013-03-01

In this study, we propose a novel concept of extending the lifetime of dye-sensitized solar cells (DSCs) and reducing the costs of re-conditioning DSCs by recycling the FTO/TiO2 substrates. The photovoltaic performances of DSCs using substrates with various cycles of dye uptake and rinse off history are tested. The results show that dye adsorption and Voc are significantly increased under multiple dye adsorption/desorption process and resulted in the improvement of power conversion efficiency. Moreover, the dyeing kinetics is faster after multiple recycling processes, which is favorable for the industrial application. With surface analysis and charge transport characteristics, we also demonstrate the optimal functionality of TiO2/dye interface for the improved Voc and efficiency. The results confirm that the improved performances are due to increased dye loading and dense packing of dye molecules. Our results are beneficial for the understanding on the extension of DSCs lifetime after long-term operation in the application of DSC modules. This approach may also be applied in the replacement of newly synthesized photosensitizes to the active cells.

Gold nanoparticle decorated multi-walled carbon nanotubes as counter electrode for dye sensitized solar cells.

PubMed

Kaniyoor, Adarsh; Ramaprabhu, Sundara

2012-11-01

A novel counter electrode material for dye sensitized solar cells (DSSCs) composed of nanostructured Au particles decorated on functionalized multi-walled carbon nanotubes (f-MWNTs) is demonstrated for the first time. MWNTs synthesized by catalytic chemical vapor deposition technique are purified and functionalized by treating with concentrated acids. Au nanoparticles are decorated on f-MWNTs by a rapid and facile microwave assisted polyol reduction method. The materials are characterized by X-ray diffractometry, Fourier transform infra red spectroscopy and electron microscopy. The DSSC fabricated with Au/f-MWNTs based counter electrode shows enhanced power conversion efficiency (eta) of 4.9% under AM 1.5G simulated solar radiation. In comparison, the reference DSSCs fabricated with f-MWNTs and Pt counter electrodes show eta of 2.1% and 4.5%. This high performance of Au/f-MWNTs counter electrode is investigated using electrochemical impedance spectroscopy and cyclic voltammetry studies.

Enhanced light absorption of silicon solar cells with dielectric nanostructured back reflector

NASA Astrophysics Data System (ADS)

Ren, Rui; Zhong, Zheng

2018-06-01

This paper investigates the light absorption property of nanostructured dielectric reflectors in silicon thin film solar cells using numerical simulation. Flat thin film solar cell with ZnO nanostructured back reflector can produce comparable photocurrent to the control model with Ag nanostructured back reflector. Furthermore, when it is integrated with nano-pillar surface decoration, a photocurrent density of 29.5 mA/cm2 can be achieved, demonstrating a photocurrent enhancement of 5% as compared to the model with Ag nanostructured back reflector.

Printable nanostructured silicon solar cells for high-performance, large-area flexible photovoltaics.

PubMed

Lee, Sung-Min; Biswas, Roshni; Li, Weigu; Kang, Dongseok; Chan, Lesley; Yoon, Jongseung

2014-10-28

Nanostructured forms of crystalline silicon represent an attractive materials building block for photovoltaics due to their potential benefits to significantly reduce the consumption of active materials, relax the requirement of materials purity for high performance, and hence achieve greatly improved levelized cost of energy. Despite successful demonstrations for their concepts over the past decade, however, the practical application of nanostructured silicon solar cells for large-scale implementation has been hampered by many existing challenges associated with the consumption of the entire wafer or expensive source materials, difficulties to precisely control materials properties and doping characteristics, or restrictions on substrate materials and scalability. Here we present a highly integrable materials platform of nanostructured silicon solar cells that can overcome these limitations. Ultrathin silicon solar microcells integrated with engineered photonic nanostructures are fabricated directly from wafer-based source materials in configurations that can lower the materials cost and can be compatible with deterministic assembly procedures to allow programmable, large-scale distribution, unlimited choices of module substrates, as well as lightweight, mechanically compliant constructions. Systematic studies on optical and electrical properties, photovoltaic performance in experiments, as well as numerical modeling elucidate important design rules for nanoscale photon management with ultrathin, nanostructured silicon solar cells and their interconnected, mechanically flexible modules, where we demonstrate 12.4% solar-to-electric energy conversion efficiency for printed ultrathin (∼ 8 μm) nanostructured silicon solar cells when configured with near-optimal designs of rear-surface nanoposts, antireflection coating, and back-surface reflector.

Bi-functional ion exchangers for enhanced performance of dye-sensitized solar cells.

PubMed

Kong, Eui-Hyun; Chang, Yong-June; Lim, Jongchul; Kim, Back-Hyun; Lee, Jung-Hoon; Kwon, Do-Kyun; Park, Taiho; Jang, Hyun Myung

2013-07-28

Ion exchange using aerosol OT (AOT) offers dye adsorption twice as fast as known methods. Moreover, it suppresses the dye-agglomeration that may cause insufficient dye-coverage on the photoelectrode surface. Consequently, its dual function of fast dye-loading and higher dye-coverage significantly improves the power conversion efficiency of dye-sensitized solar cells.

Recent advancements in plasmon-enhanced promising third-generation solar cells

NASA Astrophysics Data System (ADS)

Thrithamarassery Gangadharan, Deepak; Xu, Zhenhe; Liu, Yanlong; Izquierdo, Ricardo; Ma, Dongling

2017-01-01

The unique optical properties possessed by plasmonic noble metal nanostructures in consequence of localized surface plasmon resonance (LSPR) are useful in diverse applications like photovoltaics, sensing, non-linear optics, hydrogen generation, and photocatalytic pollutant degradation. The incorporation of plasmonic metal nanostructures into solar cells provides enhancement in light absorption and scattering cross-section (via LSPR), tunability of light absorption profile especially in the visible region of the solar spectrum, and more efficient charge carrier separation, hence maximizing the photovoltaic efficiency. This review discusses about the recent development of different plasmonic metal nanostructures, mainly based on Au or Ag, and their applications in promising third-generation solar cells such as dye-sensitized solar cells, quantum dot-based solar cells, and perovskite solar cells.

Inclusion of aggregation effect to evaluate the performance of organic dyes in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Sun, Kenan; Zhang, Weiyi; Heng, Panpan; Wang, Li; Zhang, Jinglai

2018-05-01

Two new indoline-based D-A-π-A dyes, D3F and D3F2 (see Scheme 1), are developed on the basis of the reported D3 by insertion of one or two F atoms on benzothiadiazole group. Our central aim is to explore high-efficiency organic dyes applied in dye-sensitized solar cells by inclusion of a simple group rather than by employment of new complicated groups. The performance of two new designed organic dyes, D3F and D3F2, is compared with that of D3 from various aspects including absorption spectrum, light harvesting efficiency, driving force, and open-circuit voltage. Besides the isolated dye, the interfacial property between dye and TiO2 surface is studied. D3F and D3F2 do not show absolute superiority than D3 not only for the isolated dyes but also for the monomeric adsorption system. However, D3F and D3F2 would effectively reduce the influence of aggregation resulting in the much smaller intermolecular electronic coupling. Although the aggregation has attracted much attention recently, it is studied alone in most of studies. To comprehensively evaluate the performance of dye-sensitized solar cells, it is necessary to consider aggregation along with electron injection time from dye into TiO2 rather than only static items, such as, band gap and absorption region.

Novel energy relay dyes for high efficiency dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Rahman, Md. Mahbubur; Ko, Min Jae; Lee, Jae-Joon

2015-02-01

4',6-Diamidino-2-phenylindole (DAPI) and Hoechst 33342 (H33342) were used as novel energy relay dyes (ERDs) for an efficient energy transfer to the N719 dye in I-/I3- based liquid-junction dye-sensitized solar cells (DSSCs). The introduction of the ERDs, either as an additive in the electrolyte or as a co-adsorbent, greatly enhanced the power conversion efficiencies (PCEs), mainly because of an increase in short-circuit current density (Jsc). This was attributed to the effects of non-radiative Förster-type excitation energy transfer as well as the radiative (emission)-type fluorescent energy transfer to the sensitizers. The net PCEs for the N719-sensitized DSSCs with DAPI and H33342 were 10.65% and 10.57%, and showed an improvement of 12.2% and 11.4% over control devices, respectively.4',6-Diamidino-2-phenylindole (DAPI) and Hoechst 33342 (H33342) were used as novel energy relay dyes (ERDs) for an efficient energy transfer to the N719 dye in I-/I3- based liquid-junction dye-sensitized solar cells (DSSCs). The introduction of the ERDs, either as an additive in the electrolyte or as a co-adsorbent, greatly enhanced the power conversion efficiencies (PCEs), mainly because of an increase in short-circuit current density (Jsc). This was attributed to the effects of non-radiative Förster-type excitation energy transfer as well as the radiative (emission)-type fluorescent energy transfer to the sensitizers. The net PCEs for the N719-sensitized DSSCs with DAPI and H33342 were 10.65% and 10.57%, and showed an improvement of 12.2% and 11.4% over control devices, respectively. Electronic supplementary information (ESI) available: Details of the materials and instrumentation, device fabrication, measurement and calculations of the quantum yield (Qd), calculations of the Förster radius (R0), optimization of the ERDs mixed with electrolyte according to Type-A strategy; normalized absorption profiles of the N3, Ru505, and Z907 dyes and the emission profiles of DAPI and H33342

Increased Efficiency of Solar Cells Protected by Hydrophobic and Hydrophilic Anti-Reflecting Nanostructured Glasses.

PubMed

Baquedano, Estela; Torné, Lorena; Caño, Pablo; Postigo, Pablo A

2017-12-14

We investigated the fabrication of large-area (cm²) nanostructured glasses for solar cell modules with hydrophobic and hydrophilic properties using soft lithography and colloidal lithography. Both of these techniques entail low-cost and ease of nanofabrication. We explored the use of simple 1D and 2D nanopatterns (nanowires and nanocones) and the effect of introducing disorder in the nanostructures. We observed an increase in the transmitted light for ordered nanostructures with a maximum value of 99% for wavelengths >600 nm when ordered nanocones are fabricated on the two sides of the solar glass. They produced an increment in the efficiency of the packaged solar cell with respect to the glass without nanostructures. On the one hand, the wettability properties showed that the ordering of the nanostructures improved the hydrophobicity of the solar glasses and increased their self-cleaning capacity. On the other hand, the disordered nanostructures improved the hydrophilic properties of solar glasses, increasing their anti-fogging capacity. The results show that by selecting the appropriate nanopattern, the wettability properties (hydrophobic or hydrophilic) can be easily improved without decreasing the efficiency of the solar cell underneath.

Increased Efficiency of Solar Cells Protected by Hydrophobic and Hydrophilic Anti-Reflecting Nanostructured Glasses

PubMed Central

Torné, Lorena; Caño, Pablo

2017-01-01

We investigated the fabrication of large-area (cm2) nanostructured glasses for solar cell modules with hydrophobic and hydrophilic properties using soft lithography and colloidal lithography. Both of these techniques entail low-cost and ease of nanofabrication. We explored the use of simple 1D and 2D nanopatterns (nanowires and nanocones) and the effect of introducing disorder in the nanostructures. We observed an increase in the transmitted light for ordered nanostructures with a maximum value of 99% for wavelengths >600 nm when ordered nanocones are fabricated on the two sides of the solar glass. They produced an increment in the efficiency of the packaged solar cell with respect to the glass without nanostructures. On the one hand, the wettability properties showed that the ordering of the nanostructures improved the hydrophobicity of the solar glasses and increased their self-cleaning capacity. On the other hand, the disordered nanostructures improved the hydrophilic properties of solar glasses, increasing their anti-fogging capacity. The results show that by selecting the appropriate nanopattern, the wettability properties (hydrophobic or hydrophilic) can be easily improved without decreasing the efficiency of the solar cell underneath. PMID:29240663

The application of electrospun titania nanofibers in dye-sensitized solar cells.

PubMed

Krysova, Hana; Zukal, Arnost; Trckova-Barakova, Jana; Chandiran, Aravind Kumar; Nazeeruddin, Mohammad Khaja; Grätzel, Michael; Kavan, Ladislav

2013-01-01

Titania nanofibers were fabricated using the industrial Nanospider(TM) technology. The preparative protocol was optimized by screening various precursor materials to get pure anatase nanofibers. Composite films were prepared by mixing a commercial paste of nanocrystalline anatase particles with the electrospun nanofibers, which were shortened by milling. The composite films were sensitized by Ru-bipyridine dye (coded C106) and the solar conversion efficiency was tested in a dye-sensitized solar cell filled with iodide-based electrolyte solution (coded Z960). The solar conversion efficiency of a solar cell with the optimized composite electrode (η = 7.53% at AM 1.5 irradiation) outperforms that of a solar cell with pure nanoparticle film (η = 5.44%). Still larger improvement was found for lower light intensities. At 10% sun illumination, the best composite electrode showed η = 7.04%, referenced to that of pure nanoparticle film (η = 4.69%). There are non-monotonic relations between the film's surface area, dye sorption capacity and solar performance of nanofiber-containing composite films, but the beneficial effect of the nanofiber morphology for enhancement of the solar efficiency has been demonstrated.

High-efficiency dye-sensitized solar cells with ferrocene-based electrolytes.

PubMed

Daeneke, Torben; Kwon, Tae-Hyuk; Holmes, Andrew B; Duffy, Noel W; Bach, Udo; Spiccia, Leone

2011-03-01

Dye-sensitized solar cells based on iodide/triiodide (I(-)/I(3)(-)) electrolytes are viable low-cost alternatives to conventional silicon solar cells. However, as well as providing record efficiencies of up to 12.0%, the use of I(-)/I(3)(-) in such solar cells also brings about certain limitations that stem from its corrosive nature and complex two-electron redox chemistry. Alternative redox mediators have been investigated, but these generally fall well short of matching the performance of conventional I(-)/I(3)(-) electrolytes. Here, we report energy conversion efficiencies of 7.5% (simulated sunlight, AM1.5, 1,000 W m(-2)) for dye-sensitized solar cells combining the archetypal ferrocene/ferrocenium (Fc/Fc(+)) single-electron redox couple with a novel metal-free organic donor-acceptor sensitizer (Carbz-PAHTDTT). These Fc/Fc(+)-based devices exceed the efficiency achieved for devices prepared using I(-)/I(3)(-) electrolytes under comparable conditions, revealing the great potential of ferrocene-based electrolytes in future dye-sensitized solar cells applications. This improvement results from a more favourable matching of the redox potential of the ferrocene couple with that of the new donor-acceptor sensitizer.

Molecular design of donor-acceptor dyes for efficient dye-sensitized solar cells I: a DFT study.

PubMed

El-Shishtawy, Reda M; Asiri, Abdullah M; Aziz, Saadullah G; Elroby, Shaaban A K

2014-06-01

Dye-sensitized solar cells (DSSCs) have drawn great attention as low cost and high performance alternatives to conventional photovoltaic devices. The molecular design presented in this work is based on the use of pyran type dyes as donor based on frontier molecular orbitals (FMO) and theoretical UV-visible spectra in combination with squaraine type dyes as an acceptor. Density functional theory has been used to investigate several derivatives of pyran type dyes for a better dye design based on optimization of absorption, regeneration, and recombination processes in gas phase. The frontier molecular orbital (FMO) of the HOMO and LUMO energy levels plays an important role in the efficiency of DSSCs. These energies contribute to the generation of exciton, charge transfer, dissociation and exciton recombination. The computations of the geometries and electronic structures for the predicted dyes were performed using the B3LYP/6-31+G** level of theory. The FMO energies (EHOMO, ELUMO) of the studied dyes are calculated and analyzed in the terms of the UV-visible absorption spectra, which have been examined using time-dependent density functional theory (TD-DFT) techniques. This study examined absorption properties of pyran based on theoretical UV-visible absorption spectra, with comparisons between TD-DFT using B3LYP, PBE, and TPSSH functionals with 6-31+G (d) and 6-311++G** basis sets. The results provide a valuable guide for the design of donor-acceptor (D-A) dyes with high molar absorptivity and current conversion in DSSCs. The theoretical results indicated 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran dye (D2-Me) can be effectively used as a donor dye for DSSCs. This dye has a low energy gap by itself and a high energy gap with squaraine acceptor type dye, the design that reduces the recombination and improves the photocurrent generation in solar cell.

Triphenylamine based organic dyes for dye sensitized solar cells: A theoretical approach

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

Mohankumar, V.; Pandian, Muthu Senthil; Ramasamy, P., E-mail: ramasamyp@ssn.edu.in

2016-05-23

The geometry, electronic structure and absorption spectra for newly designed triphenylamine based organic dyes were investigated by density functional theory (DFT) and time dependent density functional theory (TD-DFT) with the Becke 3-Parameter-Lee-Yang-parr(B3LYP) functional, where the 6-31G(d,p) basis set was employed. All calculations were performed using the Gaussian 09 software package. The calculated HOMO and LUMO energies show that charge transfer occurs in the molecule. Ultraviolet–visible (UV–vis) spectrum was simulated by TD-DFT in gas phase. The calculation shows that all of the dyes can potentially be good sensitizers for DSSC. The LUMOs are just above the conduction band of TiO{sub 2}more » and their HOMOs are under the reduction potential energy of the electrolytes (I{sup −}/I{sub 3}{sup −}) which can facilitate electron transfer from the excited dye to TiO{sub 2} and charge regeneration process after photo oxidation respectively. The simulated absorption spectrum of dyes match with solar spectrum. Frontier molecular orbital results show that among all the three dyes, the “dye 3” can be used as potential sensitizer for DSSC.« less

Laser desorption/ionization mass spectrometry of dye-sensitized solar cells: identification of the dye-electrolyte interaction.

PubMed

Ellis, Hanna; Leandri, Valentina; Hagfeldt, Anders; Boschloo, Gerrit; Bergquist, Jonas; Shevchenko, Denys

2015-05-01

Dye-sensitized solar cells (DSCs) have great potential to provide sustainable electricity from sunlight. The photoanode in DSCs consists of a dye-sensitized metal oxide film deposited on a conductive substrate. This configuration makes the photoanode a perfect sample for laser desorption/ionization mass spectrometry (LDI-MS). We applied LDI-MS for the study of molecular interactions between a dye and electrolyte on the surface of a TiO2 photoanode. We found that a dye containing polyoxyethylene groups forms complexes with alkali metal cations from the electrolyte, while a dye substituted with alkoxy groups does not. Guanidinium ion forms adducts with neither of the two dyes. Copyright © 2015 John Wiley & Sons, Ltd.

Discovery of black dye crystal structure polymorphs: Implications for dye conformational variation in dye-sensitized solar cells

DOE PAGES

Cole, Jacqueline M.; Low, Kian Sing; Gong, Yun

2015-11-24

Here, we present the discovery of a new crystal structure polymorph (1) and pseudopolymorph (2) of the Black Dye, one of the world’s leading dyes for dye-sensitized solar cells, DSSCs (10.4% device performance efficiency). This reveals that Black Dye molecules can adopt multiple low-energy conformers. This is significant since it challenges existing models of the Black Dye···TiO 2 adsorption process that renders a DSSC working electrode; these have assumed a single molecular conformation that refers to the previously reported Black Dye crystal structure (3). The marked structural differences observed between 1, 2, and 3 make the need for modeling multiplemore » conformations more acute. Additionally, the ordered form of the Black Dye (1) provides a more appropriate depiction of its anionic structure, especially regarding its anchoring group and NCS bonding descriptions. The tendency toward NCS ligand isomerism, evidenced via the disordered form 2, has consequences for electron injection and electron recombination in Black Dye embedded DSSC devices. Dyes 2 and 3 differ primarily by the absence or presence of a solvent of crystallization, respectively; solvent environment effects on the dye are thereby elucidated. This discovery of multiple Black Dye conformers from diffraction, with atomic-level definition, complements recently reported nanoscopic evidence for multiple dye conformations existing at a dye···TiO 2 interface, for a chemically similar DSSC dye; those results emanated from imaging and spectroscopy, but were unresolved at the submolecular level. Taken together, these findings lead to the general notion that multiple dye conformations should be explicitly considered when modeling dye···TiO 2 interfaces in DSSCs, at least for ruthenium-based dye complexes.« less

Stability and efficiency of dye-sensitized solar cells based on papaya-leaf dye.

PubMed

Suyitno, Suyitno; Saputra, Trisma Jaya; Supriyanto, Agus; Arifin, Zainal

2015-09-05

The present article reports on the enhancement of the performance and stability of natural dye-based dye-sensitized solar cells (DSSCs). Natural dyes extracted from papaya leaves (PL) were investigated as sensitizers in TiO2-based DSSCs and evaluated in comparison with N719 dye. The acidity of the papaya-leaf extract dyes was tuned by adding benzoic acid. The TiO2 film-coated fluorine-doped tin oxide glass substrates were prepared using the doctor-blade method, followed by sintering at 450 °C. The counter electrode was coated by chemically deposited catalytic platinum. The working electrodes were immersed in N719 dye and papaya dye solutions with concentrations of 8 g/100 mL. The absorbance spectra of the dyes were obtained by ultra-violet-visible spectroscopy. The energy levels of the dyes were measured by the method of cyclic voltammetry. In addition, Fourier transform infrared spectroscopy was used to determine the characteristic functionalities of the dye molecules. The DSSC based on the N719 dye displayed a highest efficiency of 0.87% whereas those based on papaya-leaf dye achieved 0.28% at pH 3.5. The observed improved efficiency of the latter was attributed to the increased current density value. Furthermore, the DSSCs based on papaya-leaf dye with pH 3.5-4 exhibited better stability than those based on N719 dye. However, further studies are required to improve the current density and stability of natural dye-based DSSCs, including the investigation of alternative dye extraction routes, such as isolating the pure chlorophyll from papaya leaves and stabilizing it. Copyright © 2015 Elsevier B.V. All rights reserved.

Stability and efficiency of dye-sensitized solar cells based on papaya-leaf dye

NASA Astrophysics Data System (ADS)

Suyitno, Suyitno; Saputra, Trisma Jaya; Supriyanto, Agus; Arifin, Zainal

2015-09-01

The present article reports on the enhancement of the performance and stability of natural dye-based dye-sensitized solar cells (DSSCs). Natural dyes extracted from papaya leaves (PL) were investigated as sensitizers in TiO2-based DSSCs and evaluated in comparison with N719 dye. The acidity of the papaya-leaf extract dyes was tuned by adding benzoic acid. The TiO2 film-coated fluorine-doped tin oxide glass substrates were prepared using the doctor-blade method, followed by sintering at 450 °C. The counter electrode was coated by chemically deposited catalytic platinum. The working electrodes were immersed in N719 dye and papaya dye solutions with concentrations of 8 g/100 mL. The absorbance spectra of the dyes were obtained by ultra-violet-visible spectroscopy. The energy levels of the dyes were measured by the method of cyclic voltammetry. In addition, Fourier transform infrared spectroscopy was used to determine the characteristic functionalities of the dye molecules. The DSSC based on the N719 dye displayed a highest efficiency of 0.87% whereas those based on papaya-leaf dye achieved 0.28% at pH 3.5. The observed improved efficiency of the latter was attributed to the increased current density value. Furthermore, the DSSCs based on papaya-leaf dye with pH 3.5-4 exhibited better stability than those based on N719 dye. However, further studies are required to improve the current density and stability of natural dye-based DSSCs, including the investigation of alternative dye extraction routes, such as isolating the pure chlorophyll from papaya leaves and stabilizing it.

Preparation of hierarchical β-Ni(OH)2 nanostructures and adsorption characterization of methyl orange dye

NASA Astrophysics Data System (ADS)

Jiao, Shujie; Jin, Yimin; Du, Qian; Zhu, Chunguang; Gao, Shiyong; Wang, Dongbo; Wang, Jinzhong

2018-05-01

The β-Ni(OH)2 nanostructures have been prepared by hydrothermal with ammonia as alkali source. The morphology of β-Ni(OH)2 evolves from hexagon sheets to flower-like hierarchical structure built up from the nanosheets as increasing the amount of ammonia. Hierarchical β-Ni(OH)2 nanostructures have strong adsorption effect on methyl orange dyes. The adsorption mechanism of β-Ni(OH)2 has been investigated, which could be expressed by pseudo-second order kinetic model with best match.

Dye-sensitized Schottky barrier solar cells

DOEpatents

Skotheim, Terje A.

1978-01-01

A low-cost dye-sensitized Schottky barrier solar cell comprised of a substrate of semiconductor with an ohmic contact on one face, a sensitizing dye adsorbed onto the opposite face of the semiconductor, a transparent thin-film layer of a reducing agent over the dye, and a thin-film layer of metal over the reducing agent. The ohmic contact and metal layer constitute electrodes for connection to an external circuit and one or the other or both are made transparent to permit light to penetrate to the dye and be absorbed therein for generating electric current. The semiconductor material chosen to be the substrate is one having a wide bandgap and which therefore is transparent; the dye selected is one having a ground state within the bandgap of the semiconductor to generate carriers in the semiconductor, and a first excited state above the conduction band edge of the semiconductor to readily conduct electrons from the dye to the semiconductor; the reducing agent selected is one having a ground state above the ground state of the sensitizer to provide a plentiful source of electrons to the dye during current generation and thereby enhance the generation; and the metal for the thin-film layer of metal is selected to have a Fermi level in the vicinity of or above the ground state of the reducing agent to thereby amply supply electrons to the reducing agent.

Dye-sensitized solar cells using laser processing techniques

NASA Astrophysics Data System (ADS)

Kim, Heungsoo; Pique, Alberto; Kushto, Gary P.; Auyeung, Raymond C. Y.; Lee, S. H.; Arnold, Craig B.; Kafafi, Zakia H.

2004-07-01

Laser processing techniques, such as laser direct-write (LDW) and laser sintering, have been used to deposit mesoporous nanocrystalline TiO2 (nc-TiO2) films for use in dye-sensitized solar cells. LDW enables the fabrication of conformal structures containing metals, ceramics, polymers and composites on rigid and flexible substrates without the use of masks or additional patterning techniques. The transferred material maintains a porous, high surface area structure that is ideally suited for dye-sensitized solar cells. In this experiment, a pulsed UV laser (355nm) is used to forward transfer a paste of commercial TiO2 nanopowder (P25) onto transparent conducting electrodes on flexible polyethyleneterephthalate (PET) and rigid glass substrates. For the cells based on flexible PET substrates, the transferred TiO2 layers were sintered using an in-situ laser to improve electron paths without damaging PET substrates. In this paper, we demonstrate the use of laser processing techniques to produce nc-TiO2 films (~10 μm thickness) on glass for use in dye-sensitized solar cells (Voc = 690 mV, Jsc = 8.7 mA/cm2, ff = 0.67, η = 4.0 % at 100 mW/cm2). This work was supported by the Office of Naval Research.

Indoor Light Performance of Coil Type Cylindrical Dye Sensitized Solar Cells.

PubMed

Kapil, Gaurav; Ogomi, Yuhei; Pandey, Shyam S; Ma, Tingli; Hayase, Shuzi

2016-04-01

A very good performance under low/diffused light intensities is one of the application areas in which dye-sensitized solar cells (DSSCs) can be utilized effectively compared to their inorganic silicon solar cell counterparts. In this article, we have investigated the 1 SUN and low intensity fluorescent light performance of Titanium (Ti)-coil based cylindrical DSSC (C-DSSC) using ruthenium based N719 dye and organic dyes such as D205 and Y123. Electrochemical impedance spectroscopic results were analyzed for variable solar cell performances. Reflecting mirror with parabolic geometry as concentrator was also utilized to tap diffused light for indoor applications. Fluorescent light at relatively lower illumination intensities (0.2 mW/cm2 to 0.5 mW/cm2) were used for the investigation of TCO-less C-DSSC performance with and without reflector geometry. Furthermore, the DSSC performances were analyzed and compared with the commercially available amorphous silicon based solar cell for indoor applications.

Dye-sensitized solar cells using natural dyes as sensitizers from Malaysia local fruit `Buah Mertajam'

NASA Astrophysics Data System (ADS)

Hambali, N. A. M. Ahmad; Roshidah, N.; Hashim, M. Norhafiz; Mohamad, I. S.; Saad, N. Hidayah; Norizan, M. N.

2015-05-01

We experimentally demonstrate the high conversion efficiency, low cost, green technology and easy to fabricate dye-sensitized solar cells (DSSCs) using natural anthocyanin dyes as sensitizers. The DSSCs was fabricated by using natural anthocyanin dyes which were extracted from different parts of the plants inclusive `Buah Mertajam', `Buah Keriang Dot', `Bunga Geti', Hibiscus, Red Spinach and Henna. The natural anthocyanin dyes that found in flower, leaves and fruits were extracted by the simple procedures. This anthocyanin dye is used to replace the expensive chemical synthetic dyes due to its ability to effectively attach into the surface of Titanium dioxide (TiO2). A natural anthocyanin dyes molecule adsorbs to each particle of the TiO2 and acts as the absorber of the visible light. A natural anthocyanin dye from Buah Mertajam shows the best performance with the conversion efficiency of 5.948% and fill factor of 0.708 followed by natural anthocyanin dyes from `Buah Keriang Dot', `Bunga Geti', Hibiscus, Red Spinach and Henna. Buah Mertajam or scientifically known as eriglossum rubiginosum is a local Malaysia fruit.

Efficient iodine-free dye-sensitized solar cells employing truxene-based organic dyes.

PubMed

Zong, Xueping; Liang, Mao; Chen, Tao; Jia, Jiangnan; Wang, Lina; Sun, Zhe; Xue, Song

2012-07-07

Two new truxene-based organic sensitizers (M15 and M16) featuring high extinction coefficients were synthesized for dye-sensitized solar cells employing cobalt electrolyte. The M16-sensitized device displays a 7.6% efficiency at an irradiation of AM1.5 full sunlight.

Hydrothermal preparation of silver telluride nanostructures and photo-catalytic investigation in degradation of toxic dyes

NASA Astrophysics Data System (ADS)

Gholamrezaei, Sousan; Salavati-Niasari, Masoud; Ghanbari, Davood; Bagheri, Samira

2016-01-01

Different morphologies of Ag2Te nanostructures were synthesized using TeCl4 as a new precursor and hydrazine hydrate as reducing agent by a hydrothermal method. Various parameters that affect on morphology and purity of nanostructures were optimized. According to our experiments the best time and temperature for preparation of this nanostructure are 12 h and 120 °C. The photo-catalytic behaviour of nanostructures in presence of UV- visible light for degradation of methyl orange was investigated. Results show that the presence of UV light is necessary for an efficient degradation of dye in aqueous solution. On the other hand, as observations propose the Ag2Te reveal a strong photoluminescence peak at room temperature that could be attributed to high level transition in the semiconductor. Nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) techniques and UV-visible scanning spectrometer (UV-Vis).

Influence of the morphology of ZnO nanostructures on luminescent and photovoltaic properties

NASA Astrophysics Data System (ADS)

Ibrayev, N. Kh.; Ilyassov, B. R.; Afanasyev, D. A.

2017-03-01

Arrays of ZnO nanorods and nanoplates are synthesized by the hydrothermal and electrochemical methods, respectively. The photoluminescence spectra indicate that the nanoplates have a more defective structure than the nanorods. The obtained ZnO nanostructures are used as the basis to construct dye-sensitized solar cells. The influence of morphology and defectiveness of ZnO nanostructures on the luminescent and photovoltaic properties of the cells is studied.

Optical properties of natural dyes on the dye-sensitized solar cells (DSSC) performance

NASA Astrophysics Data System (ADS)

Pratiwi, D. D.; Nurosyid, F.; Supriyanto, A.; Suryana, R.

2016-11-01

This study reported several natural dyes for application in dye-sensitized solar cells (DSSC). This study aims was to determine the effect of optical absorption properties of natural dyes on efficiency of DSSC. The sandwich structure of DSSC consist of TiO2 as working electrode, carbon layer as counter electrode, natural dyes as photosensitizer, and electrolyte as electron transfer media. The natural dyes used in this experiment were extracted from dragon fruit anthocyanin, mangosteen peels anthocyanin, and red cabbage anthocyanin. The absorbance of dyes solutions and the adsorption of the dye on the surface of TiO2 were characterized using UV-Vis spectrophotometer, the quantum efficiency versus wavelength was characterized using incident photon-to-current efficiency (IPCE) measurement system, and the efficiency of DSSC was calculated using I-V meter. UV-Vis characteristic curves showed that wavelength absorption of anthocyanin dye of red cabbage was 450 - 580 nm, anthocyanin of mangosteen peels was 400 - 480 nm, and anthocyanin of dragon fruit was 400 - 650 nm. Absorption spectra of the dye adsorption on the surface of TiO2 which was resulted in the highest absorbance of red cabbage anthocyanin. IPCE characteristic curves with anthocyanin dye of red cabbage, mangosteen peels anthocyanin, and dragon fruit anthocyanin resulted quantum efficiency of 0.058%; 0.047%; and 0.043%, respectively at wavelength maximum about 430 nm. I-V characteristic curves with anthocyanin dye of red cabbage, mangosteen peels anthocyanin, and dragon fruit anthocyanin resulted efficiency of 0.054%; 0.042%; and 0.024%, respectively.

Fabrication and characterization of dye-sensitized solar cells based on natural plants

NASA Astrophysics Data System (ADS)

Gu, Peng; Yang, Dingyu; Zhu, Xinghua; Sun, Hui; Li, Jitao

2018-02-01

In this paper, the dye-sensitized solar cells (DSSCs) were fabricated based on natural dyes extracting from carrot, mulberry, purple cabbage, potato, and grapes. The ultraviolet-visible spectra suggested purple cabbage and mulberry possess better absorption at 300-550 nm. The solar cells using purple cabbage as dye achieved a conversion efficiency of 0.162% with short-circuit photocurrent density (Jsc) of 0.621 mA/cm2, open circuit voltage (Voc) of 0.541 V and fill factor (FF) of 0.484. The Infrared spectra revealed the bond of Osbnd H, Csbnd C, Csbnd O, Csbnd H were existed in purple cabbage. Finally, the optimal extraction time of dyes is also presented.

Performance of Dye-Sensitized Solar Cells (DSSCs) Fabricated with Zinc Oxide (ZnO) Nanpowders and Nanorods

NASA Astrophysics Data System (ADS)

Chatterjee, Suman

2018-03-01

Due to their high efficiencies, along with lower production costs, many researchers are working on dye-sensitized solar cells (DSSCs) over last few decades as a substitute technology for nonconventional energy. Nanostructured ZnO has got many interesting properties such as wide band gap, large exciton binding energy, good exciton stability, and high breakdown strength, which are applicable as DSSC electrodes. This present work compares the device properties of DSSC fabricated using ZnO nanorods on a ZnO film and ZnO nanopowders. Different types of ZnO photoanode and dye combinations are used to study the stability and photovoltaic properties of the DSSC cell. The photovoltaic properties of the ZnO-based DSSC samples were systematically investigated. The photovoltaic properties of fabricated cell obtained are discussed in the light of band structure and density of states of different types of ZnO nanolayers. The ZnO nanorods fabricated through the sol-gel route have more uniform thickness resulting in enhanced photovoltaic properties of the fabricated device.

Electrical characterization of dye sensitized nano solar cell using natural pomegranate juice as photosensitizer

NASA Astrophysics Data System (ADS)

Adithi, U.; Thomas, Sara; Uma, V.; Pradeep, N.

2013-02-01

This paper shows Electrical characterization of Dye Sensitized Solar Cell using natural dye, extracted from the pomegranate as a photo sensitizer and ZnO nanoparticles as semiconductor. The constituents of fabricated dye sensitized solar cell were working electrode, dye, electrolyte and counter electrode. ZnO nanoparticles were synthesized and used as semiconductor in working electrode. Carbon soot was used as counter electrode. The resistance of ZnO film on ITO film was found out. There was an increase in the resistance of the film and film changes from conducting to semiconducting. Photovoltaic parameters of the fabricated cell like Short circuit current, open circuit voltage, Fill factor and Efficiency were found out. This paper shows that usage of natural dyes like pomegranate juice as sensitizer enables faster and simpler production of cheaper and environmental friendly solar cell.

Dye-sensitized solar cells consisting of dye-bilayer structure stained with two dyes for harvesting light of wide range of wavelength

NASA Astrophysics Data System (ADS)

Inakazu, Fumi; Noma, Yusuke; Ogomi, Yuhei; Hayase, Shuzi

2008-09-01

Dye-sensitized solar cells (DSCs) containing dye-bilayer structure of black dye and NK3705 (3-carboxymethyl-5-[3-(4-sulfobutyl)-2(3H)-bezothiazolylidene]-2-thioxo-4-thiazolidinone, sodium salt) in one TiO2 layer (2-TiO-BD-NK) are reported. The 2-TiO-BD-NK structure was fabricated by staining one TiO2 layer with these two dyes, step by step, under a pressurized CO2 condition. The dye-bilayer structure was observed by using a confocal laser scanning microscope. The short circuit current (Jsc) and the incident photon to current efficiency of the cell (DSC-2-TiO-BD-NK) was almost the sum of those of DSC stained with black dye only (DSC-1-TiO-BD) and DSC stained with NK3705 only (DSC-1-TiO-NK).

Ultrafast photodynamics of the indoline dye D149 adsorbed to porous ZnO in dye-sensitized solar cells.

PubMed

Rohwer, Egmont; Richter, Christoph; Heming, Nadine; Strauch, Kerstin; Litwinski, Christian; Nyokong, Tebello; Schlettwein, Derck; Schwoerer, Heinrich

2013-01-14

We investigate the ultrafast dynamics of the photoinduced electron transfer between surface-adsorbed indoline D149 dye and porous ZnO as used in the working electrodes of dye-sensitized solar cells. Transient absorption spectroscopy was conducted on the dye in solution, on solid state samples and for the latter in contact to a I(-)/I(3)(-) redox electrolyte typical for dye-sensitized solar cells to elucidate the effect of each component in the observed dynamics. D149 in a solution of 1:1 acetonitrile and tert-butyl alcohol shows excited-state lifetimes of 300±50 ps. This signature is severely quenched when D149 is adsorbed to ZnO, with the fastest component of the decay trace measured at 150±20 fs due to the charge-transfer mechanism. Absorption bands of the oxidized dye molecule were investigated to determine regeneration times which are in excess of 1 ns. The addition of the redox electrolyte to the system results in faster regeneration times, of the order of 1 ns. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Plasmonic nanoparticles enhanced dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Xu, Qi; Liu, Fang; Meng, Weisi; Huang, Yidong

2013-12-01

Here we present investigations on utilizing two kinds of plasmonic nanoparticles (NPs) to enhance the efficiency of dye sensitized solar cells (DSCs). The Au@PVP NPs is proposed and present the specialty of adhesiveness to dye molecules, which could help to localize additional dye molecules near the plasmonic NPs, hence increasing the optical absorption consequently the power conversion efficiency (PCE) of the DSCs by 30% from 3.3% to 4.3%. Meanwhile, an irregular Au-Ag alloy popcorn-shaped NPs (popcorn NPs) with plenty of fine structures is also proposed and realized to enhance the light absorption of DSC. A pronounced absorption enhancement in a broadband wavelength range is observed due to the excitation of localized surface plasmon at different wavelengths. The PCE is enhanced by 32% from 5.94% to 7.85%.

Intensity and absorbed-power distribution in a cylindrical solar-pumped dye laser

NASA Technical Reports Server (NTRS)

Williams, M. D.

1984-01-01

The internal intensity and absorbed-power distribution of a simplified hypothetical dye laser of cylindrical geometry is calculated. Total absorbed power is also calculated and compared with laboratory measurements of lasing-threshold energy deposition in a dye cell to determine the suitability of solar radiation as a pump source or, alternatively, what modifications, if any, are necessary to the hypothetical system for solar pumping.

Pigments for natural dye-sensitized solar cells from in vitro grown shoot cultures

NASA Astrophysics Data System (ADS)

Di Bari, Chiara; Forni, Cinzia; Di Carlo, Aldo; Barrajón-Catalán, Enrique; Micol, Vicente; Teoli, Federico; Nota, Paolo; Matteocci, Fabio; Frattarelli, Andrea; Caboni, Emilia; Lucioli, Simona

2017-04-01

In vitro grown shoots cultures (Prunus salicina × Prunus persica), elicited by methyl jasmonate (MJ), are reported here for the first time to prepare a natural dye for dye-sensitized solar cells (DSSC). Redox properties of the dye, its photostability, and light absorption properties suggested it as a candidate as natural photosensitizers for TiO2 photoelectrodes. Redox properties of the dye influence the DSSC production of photocurrent, thus three antioxidant assays were performed in order to characterize the antioxidant potential of this dye. The dye exhibited a high antioxidant activity in all the assays performed. Photostability assay revealed that the dye was quite stable to light. The power conversion efficiency that we obtained (0.53%) was comparable to the data by other authors with anthocyanins-based dyes from in vivo grown plants. Finally, we compared the dye with the partially purified one as photosensitizer in DSSC. The results indicated that the raw pigment from in vitro shoot cultures of P. salicina × P. persica elicited with MJ can be proposed without the needing of any other chemicals, thermal or purification process, or pH adjustments, as a dye for natural sensitized solar cells.

Molecular modification of coumarin dyes for more efficient dye sensitized solar cells

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

Sanchez-de-Armas, Rocio; San-Miguel, Miguel A.; Oviedo, Jaime

2012-05-21

In this work, new coumarin based dyes for dye sensitized solar cells (DSSC) have been designed by introducing several substituent groups in different positions of the NKX-2311 structure. Two types of substitutions have been considered: the introduction of three electron-donating groups (-OH, -NH{sub 2}, and -OCH{sub 3}) and two different substituents with steric effect: -CH{sub 2}-CH{sub 2}-CH{sub 2}- and -CH{sub 2}-HC=CH-. The electronic absorption spectra (position and width of the first band and absorption threshold) and the position of the LUMO level related to the conduction band have been used as theoretical criteria to evaluate the efficiency of the newmore » dyes. The introduction of a -NH{sub 2} group produces a redshift of the absorption maximum position and the absorption threshold, which could improve the cell efficiency. In contrast, the introduction of -CH{sub 2}-CH{sub 2}-CH{sub 2}- does not modify significantly the electronic structure of NKX-2311, but it might prevent aggregation. Finally, -CH{sub 2}-HC=CH- produces important changes both in the electronic spectrum and in the electronic structure of the dye, and it would be expected as an improvement of cell efficiency for these dyes.« less

Synthesis of zinc chlorophyll materials for dye-sensitized solar cell applications

NASA Astrophysics Data System (ADS)

Erten-Ela, Sule; Vakuliuk, Olena; Tarnowska, Anna; Ocakoglu, Kasim; Gryko, Daniel T.

2015-01-01

To design sensitizers for dye sensitized solar cells (DSSCs), a series of zinc chlorins with different substituents were synthesized. Novel zinc methyl 3-devinyl-3-hydroxymethyl-20-phenylacetylenylpyropheophorbide-a (ZnChl-1), zinc methyl 20-bromo-3-devinyl-3-hydroxymethylpyropheophorbide-a (ZnChl-2), zinc methyl 3-devinyl-3-hydroxymethyl-pyropheophorbide-a (ZnChl-3), zinc propyl 3-devinyl-3-hydroxymethyl-pyropheophorbide-a (ZnChl-4) were synthesized and their photovoltaic performances were evaluated in dye-sensitized solar cells. Photoelectrodes with a 7 μm thick nanoporous layer and a 5 μm thick light-scattering layer were used to fabricate dye sensitized solar cells. The best efficiency was obtained with ZnChl-2 sensitizer. ZnChl-2 gave a Jsc of 3.5 mA/cm2, Voc of 412 mV, FF of 0.56 and an overall conversion efficiency of 0.81 at full sun (1000 W m-2).

Versatile ruthenium(II) dye towards blue-light emitter and dye-sensitizer for solar cells

NASA Astrophysics Data System (ADS)

Zanoni, Kassio P. S.; Amaral, Ronaldo C.; Murakami Iha, Neyde Y.; Abreu, Felipe D.; de Carvalho, Idalina M. M.

2018-06-01

A versatile Ru(II) complex bearing an anthracene moiety was synthesized in our search for suitable compounds towards efficient molecular devices. The new engineered dye, cis‑[Ru(dcbH2)(NCS)2(mbpy‑anth)] (dcbH2 = 2,2‧‑bipyridyl‑4,4‧‑dicarboxylic acid, mbpy‑anth = 4‑[N‑(2‑anthryl)carbamoyl]‑4‧‑methyl‑2,2‧‑bipyridine), exhibits a blueish emission in a vibronically structured spectrum ascribed to the fluorescence of a 1LCAnth (ligand centered) excited state in the anthracene and has a potential to be exploited in the fields of smart lighting and displays. This complex was also employed in dye-sensitized solar cells with fairly efficient solar energy conversion with the use of self-assembled TiO2 compact layers beneath the TiO2 mesoporous film to prevent meso‑TiO2/dye back reactions. Further photoelectrochemical investigations through incident photon-to-current efficiency and electrochemical impedance spectra showed that the all-nano-TiO2 compact layer acts as contact layers that increase the electron harvesting in the external circuit, enhancing efficiencies up to 50%.

Versatile ruthenium(II) dye towards blue-light emitter and dye-sensitizer for solar cells.

PubMed

Zanoni, Kassio P S; Amaral, Ronaldo C; Murakami Iha, Neyde Y; Abreu, Felipe D; de Carvalho, Idalina M M

2018-06-05

A versatile Ru(II) complex bearing an anthracene moiety was synthesized in our search for suitable compounds towards efficient molecular devices. The new engineered dye, cis‑[Ru(dcbH 2 )(NCS) 2 (mbpy‑anth)] (dcbH 2 =2,2'‑bipyridyl‑4,4'‑dicarboxylic acid, mbpy‑anth=4‑[N‑(2‑anthryl)carbamoyl]‑4'‑methyl‑2,2'‑bipyridine), exhibits a blueish emission in a vibronically structured spectrum ascribed to the fluorescence of a 1 LC Anth (ligand centered) excited state in the anthracene and has a potential to be exploited in the fields of smart lighting and displays. This complex was also employed in dye-sensitized solar cells with fairly efficient solar energy conversion with the use of self-assembled TiO 2 compact layers beneath the TiO 2 mesoporous film to prevent meso‑TiO 2 /dye back reactions. Further photoelectrochemical investigations through incident photon-to-current efficiency and electrochemical impedance spectra showed that the all-nano-TiO 2 compact layer acts as contact layers that increase the electron harvesting in the external circuit, enhancing efficiencies up to 50%. Copyright © 2018 Elsevier B.V. All rights reserved.

Contribution of Nanostructures in High Performance Solar Cells

NASA Astrophysics Data System (ADS)

Aly, Abouelmaaty M.; Ebrahim, Essamudin A.; Sweelem, Emad

2017-11-01

Nanotechnology has great contributions in various fields, especially in solar energy conversion through solar cells (SCs). Nanostructured SCs can provide high performance with lower fabrication costs. The transition from fossil fuel energy to renewable sustainable energy represents a major technological challenge for the world. In the last years, the industry of SCs has grown rapidly due to strong attention in renewable energy in order to handle the problem of global climate change that is now believed to occur due to use of the fossil fuels. Cost is an influential factor in the eventual success of any solar technology, since inexpensive SCs are needed to produce electricity, especially for rural areas and for third world countries. Therefore, new developments in nanotechnology may open the door for the production of inexpensive and more efficient SCs by reducing the manufacturing costs of SCs. Utilizing nanotechnology in cheaper SCs will help maintain the environment. This article covers a review of the progress that has been made to-date to enhance efficiencies of various nanostructures used in SCs, including utilizations of all the wavelengths present in of the solar spectrum.

Near-infrared absorbing squarylium dyes with linearly extended π-conjugated structure for dye-sensitized solar cell applications.

PubMed

Maeda, Takeshi; Hamamura, Yuuto; Miyanaga, Kyohei; Shima, Naoki; Yagi, Shigeyuki; Nakazumi, Hiroyuki

2011-11-18

A novel class of near-infrared absorbing squarylium sensitizers with linearly extended π-conjugated structures, which were obtained by Pd-catalyzed cross-coupling reactions with stannylcyclobutenediones, has been developed for dye-sensitized solar cells. The cells based on these dyes exhibited a significant spectral response in the near-infrared region over 750 nm in addition to the visible region.

Asymmetric Zinc Phthalocyanines as Dye-Sensitized Solar Cells

NASA Astrophysics Data System (ADS)

Tunc, Gulenay; Yavuz, Yunus; Gurek, Aysegul; Canimkurbey, Betul; Kosemen, Arif; San, Sait Eren; Ahsen, Vefa

Dye-sensitized solar cells (DSSCs) have received increasing attention due to their high incident to photon efficiency, easy fabrication and low production cost . Tremendous research efforts have been devoted to the development of new and efficient sensitizers suitable for practical use. In TiO2-based DSSCs, efficiencies of up to 11.4% under simulated sunlight have been obtained with rutheniumepolypyridyl complexes. However, the main drawback of ruthenium complexes is the lack of absorption in the red region of the visible light and the high cost. For this reason, dyes with large and stable p-conjugated systems such as porphyrins and phthalocyanines are important classes of potential sensitizers for highly efficient DSSCs. Phthalocyanines (Pcs) have been widely used as sensitizers because of their improved light-harvesting properties in the far red- and near-IR spectral regions and their extraordinary robustness [1]. In this work, a series of asymmetric Zn(II) Pcs bearing a carboxylic acid group and six hexylthia groups either at the peripheral or non-peripheral positions have been designed and synthesized to investigate the influence of the COOH group and the positions of hexylthia groups on the dye-sensitized solar cell (DSSC) performance.

Acene-modified triphenylamine dyes for dye-sensitized solar cells: a computational study.

PubMed

Fan, Wenjie; Tan, Dazhi; Deng, Wei-Qiao

2012-06-04

A series of metal-free acene-modified triphenylamine dyes (benzene to pentacene, denoted as TPA-AC1 to TPA-AC5) are investigated as organic sensitizers for application in dye-sensitized solar cells (DSSCs). A combination of density functional theory (DFT), density functional tight-binding (DFTB), and time-dependent DFT (TDDFT) approaches is employed. The effects of acene units on the spectra and electrochemical properties of the acene-modified TPA organic dyes are demonstrated. The dye/(TiO(2))(46) anatase nanoparticle systems are also simulated to show the electronic structures at the interface. The results show that from TPA-AC1 to TPA-AC5 with increasing sizes of the acenes, the absorption and fluorescence spectra are systematically broadened and red-shifted, but the oscillator strength and electron injection properties are reduced. The molecular orbital contributions show increasing localization on the bridging acene units from TPA-AC1 to TPA-AC5. From the theoretical examination of some key parameters including free enthalpy related to the electron injection, light-harvesting efficiency, and the shift of semiconductor conduction band, TPA-AC3 with an anthracene moiety demonstrates a balance of the above crucial factors. TPA-AC3 is expected to be a promising dye with desirable energetic and spectroscopic parameters in the DSSC field, which is consistent with recent experimental work. This study is expected to deepen our understanding of TPA-based organic dyes and assist the molecular design of new metal-free dyes for the further optimization of DSSCs. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and characterization of organic dyes with various electron-accepting substituents for p-type dye-sensitized solar cells.

PubMed

Weidelener, Martin; Powar, Satvasheel; Kast, Hannelore; Yu, Ze; Boix, Pablo P; Li, Chen; Müllen, Klaus; Geiger, Thomas; Kuster, Simon; Nüesch, Frank; Bach, Udo; Mishra, Amaresh; Bäuerle, Peter

2014-11-01

Four new donor-π-acceptor dyes differing in their acceptor group have been synthesized and employed as model systems to study the influence of the acceptor groups on the photophysical properties and in NiO-based p-type dye-sensitized solar cells. UV/Vis absorption spectra showed a broad range of absorption coverage with maxima between 331 and 653 nm. Redox potentials as well as HOMO and LUMO energies of the dyes were determined from cyclic voltammetry measurements and evaluated concerning their potential use as sensitizers in p-type dye-sensitized solar cells (p-DSCs). Quantum-chemical density functional theory calculations gave further insight into the frontier orbital distributions, which are relevant for the electronic processes in p-DSCs. In p-DSCs using an iodide/triiodide-based electrolyte, the polycyclic 9,10-dicyano-acenaphtho[1,2-b]quinoxaline (DCANQ) acceptor-containing dye gave the highest power conversion efficiency of 0.08%, which is comparable to that obtained with the perylenemonoimide (PMI)-containing dye. Interestingly, devices containing the DCANQ-based dye achieve a higher V(OC) of 163 mV compared to 158 mV for the PMI-containing dye. The result was further confirmed by impedance spectroscopic analysis showing higher recombination resistance and thus a lower recombination rate for devices containing the DCANQ dye than for PMI dye-based devices. However, the use of the strong electron-accepting tricyanofurane (TCF) group played a negative role in the device performance, yielding an efficiency of only 0.01% due to a low-lying LUMO energy level, thus resulting in an insufficient driving force for efficient dye regeneration. The results demonstrate that a careful molecular design with a proper choice of the acceptor unit is essential for development of sensitizers for p-DSCs. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solar light induced and TiO2 assisted degradation of textile dye reactive blue 4.

PubMed

Neppolian, B; Choi, H C; Sakthivel, S; Arabindoo, B; Murugesan, V

2002-03-01

Aqueous solutions of reactive blue 4 textile dye are totally mineralised when irradiated with TiO2 photocatalyst. A solution containing 4 x 10(-4) M dye was completely degraded in 24 h irradiation time. The intensity of the solar light was measured using Lux meter. The results showed that the dye molecules were completely degraded to CO2, SO4(2-), NO3-, NH4+ and H2O under solar irradiation. The addition of hydrogen peroxide and potassium persulphate influenced the photodegradation efficiency. The rapidity of photodegradation of dye intermediates were observed in the presence of hydrogen peroxide than in its absence. The auxiliary chemicals such as sodium carbonate and sodium chloride substantially affected the photodegradation efficiency. High performance liquid chromatography and chemical oxygen demand were used to study the mineralisation and degradation of the dye respectively. It is concluded that solar light induced degradation of textile dye in wastewater is a viable technique for wastewater treatment.

Electron Transport in Quasi-Two-Dimensional Porous Network of Titania Nanoparticles, Incorporating Electrical and Optical Advantages in Dye-Sensitized Solar Cells.

PubMed

Javadi, Mohammad; Alizadeh, Saba; Khosravi, Yusef; Abdi, Yaser

2016-11-04

The integration of fast electron transport and large effective surface area is critical to attaining higher gains in the nanostructured photovoltaic devices. Here, we report facilitated electron transport in the quasi-two-dimensional (Q2D) porous TiO 2 . Liquid electrolyte dye-sensitized solar cells were prepared by utilizing photoanodes based on the Q2D porous substructures. Due to electron confinement in a microscale porous medium, directional diffusion toward collecting electrode is induced into the electron transport. Our measurements based on the photocurrent and photovoltage time-of-flight transients show that at higher Fermi levels, the electron diffusion coefficient in the Q2D porous TiO 2 is about one order of magnitude higher when compared with the conventional layer of porous TiO 2 . The results show that microstructuring of the porous TiO 2 leads to an approximately threefold improvement in the electron diffusion length. Such a modification may considerably affects the electrical functionality of moderate or low performance dye-sensitized solar cells for which the internal gain or collection efficiency is typically low. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enhancing the power conversion efficiency of dye-sensitized solar cells via molecular plasmon-like excitations.

PubMed

Li, Jian-Hao; Gryn'ova, Ganna; Prlj, Antonio; Corminboeuf, Clémence

2017-02-21

We introduce a tactic for employing molecular plasmon-like excitations to enhance solar-to-electric power conversion efficiency of dye-sensitized solar cells. We offer general design principles of dimeric dyes, in which a strong plasmonic interaction between two π-conjugated moieties is promoted. The π-stacked conformations of these dimeric dyes result in a desirable broadened absorption and a longer absorption onset wavelength.

TiO2 Nanostructure Synthesized by Sol-Gel for Dye Sensitized Solar Cells as Renewable Energy Source

NASA Astrophysics Data System (ADS)

Ramelan, A. H.; Wahyuningsih, S.; Saputro, S.; Supriyanto, E.; Hanif, Q. A.

2017-02-01

The use of renewable materials as a constituent of a smart alternative energy such as the use of natural dyes for light harvesting needs to be developed. Synthesis of anatase titanium dioxide (TiO2) and fabrication Dye-Sensitized Solar Cell (DSSC) using dye-based of anthocyanin from purple sweet potato (Ipomoea batatas L.) as a photosensitizer had been done. Synthesis TiO2 through sol-gel process with the addition of triblock copolymer Pluronic F127 template was controlled at pH 3 whereas calcination was carried out at a temperature of 500 °C, 550 °C and 600 °C. The obtained TiO2 were analyzed by XRD, SAA, and SEM. The conclusion is anatase TiO2 obtained until annealing up to 600 °C. Self-assembly Pluronic F127 triblock copolymer capable of restraining the growth of TiO2 crystals. Retention growth of TiO2 mesoporous produces material character that can be used as builders photoanode DSSC with natural sensitizer anthocyanin from purple sweet potatoes. Based on the analysis of X-ray diffraction patterns and surface area analyser, the higher the calcination temperature the greater the size of the anatase crystals is obtained, however, the smaller its surface area. Purple sweet potato anthocyanin’s dyed on to TiO2 was obtained a good enough performance for DSSC’s and gain the optimum performance from DSSC’s system built with mesoporous TiO2 annealed 550 °C using flavylium form anthocyanin.

Altering the self-organization of dyes on titania with dyeing solvents to tune the charge-transfer dynamics of sensitized solar cells.

PubMed

Wang, Yinglin; Yang, Lin; Zhang, Jing; Li, Renzhi; Zhang, Min; Wang, Peng

2014-04-14

Herein we selected the model organic donor-acceptor dye C218 and modulated the self-organization of dye molecules on the surface of titania by changing the dyeing solvent from chlorobenzene to a mixture of acetonitrile and tert-butanol. We further unveiled the relationship between the microstructure of a dye layer and the multichannel charge-transfer dynamics that underlie the photovoltaic performance of dye-sensitized solar cells. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solar energy conversion with tunable plasmonic nanostructures for thermoelectric devices.

PubMed

Xiong, Yujie; Long, Ran; Liu, Dong; Zhong, Xiaolan; Wang, Chengming; Li, Zhi-Yuan; Xie, Yi

2012-08-07

The photothermal effect in localized surface plasmon resonance (LSPR) should be fully utilized when integrating plasmonics into solar technologies for improved light absorption. In this communication, we demonstrate that the photothermal effect of silver nanostructures can provide a heat source for thermoelectric devices for the first time. The plasmonic band of silver nanostructures can be facilely manoeuvred by tailoring their shapes, enabling them to interact with photons in different spectral ranges for the efficient utilization of solar light. It is anticipated that this concept can be extended to design a photovoltaic-thermoelectric tandem cell structure with plasmonics as mediation for light harvesting.

Piper Ornatum and Piper Betle as Organic Dyes for TiO2 and SnO2 Dye Sensitized Solar Cells

NASA Astrophysics Data System (ADS)

Hayat, Azwar; Putra, A. Erwin E.; Amaliyah, Novriany; Hayase, Shuzi; Pandey, Shyam. S.

2018-03-01

Dye sensitized solar cell (DSSC) mimics the principle of natural photosynthesis are now currently investigated due to low manufacturing cost as compared to silicon based solar cells. In this report, we utilized Piper ornatum (PO) and Piper betle (PB) as sensitizer to fabricate low cost DSSCs. We compared the photovoltaic performance of both sensitizers with Titanium dioxide (TiO2) and Tin dioxide (SnO2) semiconductors. The results show that PO and PB dyes have higher Short circuit current (Jsc) when applied in SnO2 compared to standard TiO2 photo-anode film even though the Open circuit voltage (Voc) was hampered on SnO2 device. In conclusion, from the result, higher electron injections can be achieved by choosing appropriate semiconductors with band gap that match with dyes energy level as one of strategy for further low cost solar cell.

Highly Efficient Plastic Crystal Ionic Conductors for Solid-state Dye-sensitized Solar Cells

PubMed Central

Hwang, Daesub; Kim, Dong Young; Jo, Seong Mu; Armel, Vanessa; MacFarlane, Douglas R.; Kim, Dongho; Jang, Sung-Yeon

2013-01-01

We have developed highly efficient, ambient temperature, solid-state ionic conductors (SSICs) for dye-sensitized solar cells (DSSCs) by doping a molecular plastic crystal, succinonitrile (SN), with trialkyl-substituted imidazolium iodide salts. High performance SSICs with enhanced ionic conductivity (2–4 mScm−1) were obtained. High performance solid-state DSSCs with power conversion efficiency of 7.8% were fabricated using our SSICs combined with unique hierarchically nanostructured TiO2 sphere (TiO2-SP) photoelectrodes; these electrodes have significant macroporosity, which assists penetration of the solid electrolyte into the electrode. The performance of our solid-state DSSCs is, to the best of our knowledge, the highest reported thus far for cells using plastic crystal-based SSICs, and is comparable to that of the state-of-the-art DSSCs which use ionic liquid type electrolytes. This report provides a logical strategy for the development of efficient plastic crystal-based SSICs for DSSCs and other electrochemical devices. PMID:24343425

Transforming Benzophenoxazine Laser Dyes into Chromophores for Dye-Sensitized Solar Cells: A Molecular Engineering Approach

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

Schröder, Florian A. Y. N.; Cole, Jacqueline M.; Waddell, Paul G.

2015-02-03

The re-functionalization of a series of four well-known industrial laser dyes, based on benzophenoxazine, is explored with the prospect of molecularly engineering new chromophores for dye-sensitized solar cell (DSC) applications. Such engineering is important since a lack of suitable dyes is stifling the progress of DSC technology. The conceptual idea involves making laser dyes DSC-active by chemical modification, while maintaining their key property attributes that are attractive to DSC applications. This molecular engineering follows a step-wise approach. Firstly, molecular structures and optical absorption properties are determined for the parent laser dyes: Cresyl Violet (1); Oxazine 170 (2); Nile Blue Amore » (3), Oxazine 750 (4). These reveal structure-property relationships which define the prerequisites for computational molecular design of DSC dyes; the nature of their molecular architecture (D-π-A) and intramolecular charge transfer. Secondly, new DSC dyes are computationally designed by the in silico addition of a carboxylic acid anchor at various chemical substitution points in the parent laser dyes. A comparison of the resulting frontier molecular orbital energy levels with the conduction band edge of a TiO2 DSC photoanode and the redox potential of two electrolyte options I-/I3- and Co(II/III)tris(bipyridyl) suggests promise for these computationally designed dyes as co-sensitizers for DSC applications.« less

Design of organic dyes and cobalt polypyridine redox mediators for high-efficiency dye-sensitized solar cells.

PubMed

Feldt, Sandra M; Gibson, Elizabeth A; Gabrielsson, Erik; Sun, Licheng; Boschloo, Gerrit; Hagfeldt, Anders

2010-11-24

Dye-sensitized solar cells (DSCs) with cobalt-based mediators with efficiencies surpassing the record for DSCs with iodide-free electrolytes were developed by selecting a suitable combination of a cobalt polypyridine complex and an organic sensitizer. The effect of the steric properties of two triphenylamine-based organic sensitizers and a series of cobalt polypyridine redox mediators on the overall device performance in DSCs as well as on transport and recombination processes in these devices was compared. The recombination and mass-transport limitations that, previously, have been found to limit the performance of these mediators were avoided by matching the properties of the dye and the cobalt redox mediator. Organic dyes with higher extinction coefficients than the standard ruthenium sensitizers were employed in DSCs in combination with outer-sphere redox mediators, enabling thinner TiO(2) films to be used. Recombination was reduced further by introducing insulating butoxyl chains on the dye rather than on the cobalt redox mediator, enabling redox couples with higher diffusion coefficients and more suitable redox potential to be used, simultaneously improving the photocurrent and photovoltage of the device. Optimization of DSCs sensitized with a triphenylamine-based organic dye in combination with tris(2,2'-bipyridyl)cobalt(II/III) yielded solar cells with overall conversion efficiencies of 6.7% and open-circuit potentials of more than 0.9 V under 1000 W m(-2) AM1.5 G illumination. Excellent performance was also found under low light intensity indoor conditions.

Optoelectronic and Photovoltaic Performances of Pyridine Based Monomer and Polymer Capped ZnO Dye-Sensitized Solar Cells.

PubMed

Singh, Satbir; Raj, Tilak; Singh, Amarpal; Kaur, Navneet

2016-06-01

The present research work describes the comparative analysis and performance characteristics of 4-pyridine based monomer and polymer capped ZnO dye-sensitized solar cells. The N, N-dimethyl-N4-((pyridine-4yl)methylene) propaneamine (4,monomer) and polyamine-4-pyridyl Schiff base (5, polymer) dyes were synthesized through one step condensation reaction between 4-pyridinecarboxaldehyde 1 and N, N-dimethylpropylamine 2/polyamine 3. Products obtained N, N-dimethyl-N4-((pyridine-4yl)methylene)propaneamine (4) and polyamine-4-pyridyl Schiff base (5) were purified and characterized using 1H, 13C NMR, mass, IR and CHN spectroscopy. Both the dyes 4 and 5 were further coated over ZnO nanoparticles and characterized using SEM, DLS and XRD analysis. Absorption profile and emission profile was monitored using fluorescence and UV-Vis absorption spectroscopy. A thick layer of these inbuilt dye linked ZnO nanoparticles of dyes (4) and (5) was pasted on one of the conductive side of ITO glass followed with a liquid electrolyte and counter electrode of the same conductive glass. Polyamine-4-pyridyl Schiff base polymer (5) decorated dye sensitized solar cell has shown better exciting photovoltaic properties in the form of short circuit current density (J(sc) = 6.3 mA/cm2), open circuit photo voltage (V(oc) = 0.7 V), fill factor (FF = 0.736) than monomer decorated dye sensitized solar cell. Polymer dye (5) based ZnO solar cell has shown a maximum solar power to electrical conversion efficiency of 3.25%, which is enhanced by 2.16% in case of monomer dye based ZnO solar cell under AM 1.5 sun illuminations.

Morphology Dependent Photocatalytic Activity of α-MoO3 Nanostructures Towards Mutagenic Acridine Orange Dye.

PubMed

2015-06-01

The morphological evolutions of orthorhombic molybdenum oxide nanostructures with high crystalline nature have been successfully synthesized by combining low-temperature sol-gel and annealing processes. Strong influence of gelation temperature is a factor facilitated to control the material morphology. Morphological transformations like nanospheres, nanoplatelets, mixtures of hexagonal platelets, and one-dimensional nanobars were obtained. The possible morphological formation mechanism has been proposed as a self-assemble process of nucleation and a mechanism for particle growth by Ostwald ripening. The as-prepared nanostructures were recognized as photocatalysts for the degradation of Acridine Orange under Ultra Violet light. The obtained mixed morphology (hexagonal nanoplatelets and nanobars) showed a high photocatalytic property to degrade mutagenic Acridine Orange dye. Moreover, they could be easily recycled without changing the photocatalytic activity due to their 1-Dimensional and 2-Dimensional nanostructure property.

Fabrication, Optimization and Characterization of Natural Dye Sensitized Solar Cell

PubMed Central

Ghann, William; Kang, Hyeonggon; Sheikh, Tajbik; Yadav, Sunil; Chavez-Gil, Tulio; Nesbitt, Fred; Uddin, Jamal

2017-01-01

The dyes extracted from pomegranate and berry fruits were successfully used in the fabrication of natural dye sensitized solar cells (NDSSC). The morphology, porosity, surface roughness, thickness, absorption and emission characteristics of the pomegranate dye sensitized photo-anode were studied using various analytical techniques including FESEM, EDS, TEM, AFM, FTIR, Raman, Fluorescence and Absorption Spectroscopy. Pomegranate dye extract has been shown to contain anthocyanin which is an excellent light harvesting pigment needed for the generation of charge carriers for the production of electricity. The solar cell’s photovoltic performance in terms of efficiency, voltage, and current was tested with a standard illumination of air-mass 1.5 global (AM 1.5 G) having an irradiance of 100 mW/cm2. After optimization of the photo-anode and counter electrode, a photoelectric conversion efficiency (η) of 2%, an open-circuit voltage (Voc) of 0.39 mV, and a short-circuit current density (Isc) of 12.2 mA/cm2 were obtained. Impedance determination showed a relatively low charge-transfer resistance (17.44 Ω) and a long lifetime, signifying a reduction in recombination losses. The relatively enhanced efficiency is attributable in part to the use of a highly concentrated pomegranate dye, graphite counter electrode and TiCl4 treatment of the photo-anode. PMID:28128369

Fabrication, Optimization and Characterization of Natural Dye Sensitized Solar Cell

NASA Astrophysics Data System (ADS)

Ghann, William; Kang, Hyeonggon; Sheikh, Tajbik; Yadav, Sunil; Chavez-Gil, Tulio; Nesbitt, Fred; Uddin, Jamal

2017-01-01

The dyes extracted from pomegranate and berry fruits were successfully used in the fabrication of natural dye sensitized solar cells (NDSSC). The morphology, porosity, surface roughness, thickness, absorption and emission characteristics of the pomegranate dye sensitized photo-anode were studied using various analytical techniques including FESEM, EDS, TEM, AFM, FTIR, Raman, Fluorescence and Absorption Spectroscopy. Pomegranate dye extract has been shown to contain anthocyanin which is an excellent light harvesting pigment needed for the generation of charge carriers for the production of electricity. The solar cell’s photovoltic performance in terms of efficiency, voltage, and current was tested with a standard illumination of air-mass 1.5 global (AM 1.5 G) having an irradiance of 100 mW/cm2. After optimization of the photo-anode and counter electrode, a photoelectric conversion efficiency (η) of 2%, an open-circuit voltage (Voc) of 0.39 mV, and a short-circuit current density (Isc) of 12.2 mA/cm2 were obtained. Impedance determination showed a relatively low charge-transfer resistance (17.44 Ω) and a long lifetime, signifying a reduction in recombination losses. The relatively enhanced efficiency is attributable in part to the use of a highly concentrated pomegranate dye, graphite counter electrode and TiCl4 treatment of the photo-anode.

Effect of Mixing Dyes and Solvent in Electrolyte Toward Characterization of Dye Sensitized Solar Cell Using Natural Dyes as The Sensitizer

NASA Astrophysics Data System (ADS)

Puspitasari, Nurrisma; Nurul Amalia, Silviyanti S.; Yudoyono, Gatut; Endarko

2017-07-01

Dye Sensitized Solar Cell (DSSC) using natural dyes (chlorophyll, curcumin from turmeric extract, and anthocyanin from mangosteen extract) have been successfully fabricated for determining the effect of variation natural dyes, mixing dyes and acetonitrile in electrolyte toward characterization of DSSC. DSSC consists of five parts namely ITO (Indium Tin Oxide) as a substrate; TiO2 as semiconductor materials; natural dyes as an electron donor; electrolyte as electron transfer; and carbon as a catalyst that can convert light energy into electric energy. Two types of gel electrolyte based on PEG that mixed with liquid electrolyte have utilized for analyzing the lifetime of DSSC. Type I used distilled water as a solvent whilst type II used acetonitrile as a solvent with addition of concentration of KI and iodine. The main purpose of study was to investigate influence of solvent in electrolyte, variation of natural dyes and mixing dyes toward an efficiency that resulted by DSSC. The result showed that electrolyte type II is generally better than type I with efficiency 0,0556 and 0,0456 %, respectively. An efficiency values which resulted from a variation of mixed three natural dyes showed the greatest efficiency compared to mixed two natural dyes and one dye, with an efficiency value can be achieved at 0,0194 % for chlorophyll; 0,111 % for turmeric; 0,0105 % for mangosteen; 0,0244% (mangosteen and chlorophyll); 0,0117 % (turmeric and mangosteen); 0,0158 % (turmeric and chlorophyll); and 0.0566 % (mixed three natural dyes).

Optically transparent FTO-free cathode for dye-sensitized solar cells.

PubMed

Kavan, Ladislav; Liska, Paul; Zakeeruddin, Shaik M; Grätzel, Michael

2014-12-24

The woven fabric containing electrochemically platinized tungsten wire is an affordable flexible cathode for liquid-junction dye-sensitized solar cells with the I3(-)/I(-) redox mediator and electrolyte solution consisting of ionic liquids and propionitrile. The fabric-based electrode outperforms the thermally platinized FTO in serial ohmic resistance and charge-transfer resistance for triiodide reduction, and it offers comparable or better optical transparency in the visible and particularly in the near-IR spectral region. The electrode exhibits good stability during electrochemical loading and storage at open circuit. The dye-sensitized solar cells with a C101-sensitized titania photoanode and either Pt-W/PEN or Pt-FTO cathodes show a comparable performance.

Synthesis, Characterization and Reactivity of Nanostructured Zero-Valent Iron Particles for Degradation of Azo Dyes

NASA Astrophysics Data System (ADS)

Mikhailov, Ivan; Levina, Vera; Leybo, Denis; Masov, Vsevolod; Tagirov, Marat; Kuznetsov, Denis

Nanostructured zero-valent iron (NSZVI) particles were synthesized by the method of ferric ion reduction with sodium borohydride with subsequent drying and passivation at room temperature in technical grade nitrogen. The obtained sample was characterized by means of X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and dynamic light scattering studies. The prepared NSZVI particles represent 100-200nm aggregates, which consist of 20-30nm iron nanoparticles in zero-valent oxidation state covered by thin oxide shell. The reactivity of the NSZVI sample, as the removal efficiency of refractory azo dyes, was investigated in this study. Two azo dye compounds, namely, orange G and methyl orange, are commonly detected in waste water of textile production. Experimental variables such as NSZVI dosage, initial dye concentration and solution pH were investigated. The kinetic rates of degradation of both dyes by NSZVI increased with the decrease of solution pH from 10 to 3 and with the increase of NSZVI dosage, but decreased with the increase of initial dye concentration. The removal efficiencies achieved for both orange G and methyl orange were higher than 90% after 80min of treatment.

Dyes and Redox Couples with Matched Energy Levels: Elimination of the Dye-Regeneration Energy Loss in Dye-Sensitized Solar Cells.

PubMed

Jiang, Dianlu; Darabedian, Narek; Ghazarian, Sevak; Hao, Yuanqiang; Zhgamadze, Maxim; Majaryan, Natalie; Shen, Rujuan; Zhou, Feimeng

2015-11-16

In dye-sensitized solar cells (DSSCs), a significant dye-regeneration force (ΔG(reg)(0)≥0.5 eV) is usually required for effective dye regeneration, which results in a major energy loss and limits the energy-conversion efficiency of state-of-art DSSCs. We demonstrate that when dye molecules and redox couples that possess similar conjugated ligands are used, efficient dye regeneration occurs with zero or close-to-zero driving force. By using Ru(dcbpy)(bpy)2(2+) as the dye and Ru(bpy)2(MeIm)2(3+//2+) as the redox couple, a short-circuit current (J(sc)) of 4 mA cm(-2) and an open-circuit voltage (V(oc)) of 0.9 V were obtained with a ΔG(reg)(0) of 0.07 eV. The same was observed for the N3 dye and Ru(bpy)2(SCN)2(1+/0) (ΔG(reg)(0)=0.0 eV), which produced an J(sc) of 2.5 mA cm(-2) and V(oc) of 0.6 V. Charge recombination occurs at pinholes, limiting the performance of the cells. This proof-of-concept study demonstrates that high V(oc) values can be attained by significantly curtailing the dye-regeneration force. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Self-Assembly of Cis-Configured Squaraine Dyes at the TiO2-Dye Interface: Far-Red Active Dyes for Dye-Sensitized Solar Cells.

PubMed

Punitharasu, Vellimalai; Mele Kavungathodi, Munavvar Fairoos; Nithyanandhan, Jayaraj

2018-05-16

To synergize both steric and electronic factors in designing the dyes for dye-sensitized solar cells, a series of cis-configured unsymmetrical squaraine dyes P11-P15 with suitably functionalized alkyl groups and squaric acid units containing the electron-withdrawing groups were synthesized, respectively. These dyes capture the importance of (i) the effect and position of branched alkyl groups, (ii) mono- and di-anchoring groups containing dyes, and (iii) further appending the alkyl groups through the cyanoester vinyl unit on the central squaric acid units of D-A-D-based cis-configured squaraine dyes. All the above factors govern the controlled self-assembly of the dyes on the TiO 2 surface which helps to broaden the absorption profile of the dyes with an increased energy-harvesting process. With respect to the position of the branched alkyl groups, dye P11 with the sp 3 -C and N-alkyl groups away from the TiO 2 surface showed a better device efficiency of 5.98% ( J sc of 14.46 mA cm -2 , V oc of 0.576 V, and ff of 71.8%) than its positional isomer P12 with 3.45% ( J sc of 8.78 mA cm -2 , V oc of 0.554 V, and ff of 70.9%). However, with respect to the dyes containing mono- and di-anchoring groups, P13 with two anchoring units exhibited a superior device performance of 7.58% ( J sc of 17.12 mA cm -2 , V oc of 0.618 V, and ff of 71.7%) in the presence of optically transparent co-adsorbent CDCA (3α,7α-dihydroxy-5β-cholanic acid) than dyes P11 and P12.

Newer approach of using alternatives to (Indium doped) metal electrodes, dyes and electrolytes in dye sensitized solar cell

NASA Astrophysics Data System (ADS)

Patni, Neha; Sharma, Pranjal; Pillai, Shibu G.

2018-04-01

This work demonstrates the PV study of dye sensitised solar cells by fabricating the (PV) cell using the ITO, FTO and AZO glass substrate. Dyes used for the fabrication were extracted from beetroot and spinach and a cocktail dye by mixing both of the dyes was also prepared. Similarly the three dufferent electrolytes used were iodide-triiodide couple, polyaniline and mixture of polyaniline and iodide couple. Mixed dye and mixed electrolyte has emerged as the highest efficient cell. The electrical characterisation shows that the highest power conversion efficiency of 1.86% was achieved by FTO substrate, followed by efficiency of 1.83% by AZO substrate and efficiency of 1.63% with ITO substrate using mixed dye and mixed electrolyte approach. This justifies that FTO and AZO shows better efficiency and hence proposed to be used as an alternative to indium free system.

Influence of structural variations in push-pull zinc porphyrins on photovoltaic performance of dye-sensitized solar cells.

PubMed

Yi, Chenyi; Giordano, Fabrizio; Cevey-Ha, Ngoc-Le; Tsao, Hoi Nok; Zakeeruddin, Shaik M; Grätzel, Michael

2014-04-01

We designed and synthesized two new zinc porphyrin dyes for dye-sensitized solar cells (DSCs). Subtle molecular structural variation in the dyes significantly influenced the performance of the DSC devices. By utilizing these dyes in combination with a cobalt-based redox electrolyte using a photoanode made of mesoporous TiO2 , we achieved a power conversion efficiency (PCE) of up to 12.0 % under AM 1.5 G (100 mW cm(-2)) simulated solar light. Moreover, we obtained a high PCE of 6.4 % for solid-state dye-sensitized solar cells by using 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene as a hole-transporting material. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

To probe the equivalence and opulence of nanocrystal and nanotube based dye-sensitized solar cells

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

Jyoti, Divya, E-mail: divyabathla17@gmail.com; Mohan, Devendra

2016-05-06

Dye-Sensitized solar cells based on TiO{sub 2} nanocrystal and TiO{sub 2} nanotubes have been fabricated by a simple sol-gel hydrothermal process and their performances have been compared. Current density and voltage (JV) characteristics and incident photon to current conversion efficiency (IPCE) plots have been set as criterion to check which one is better as a photoanode candidate in dye-sensitized solar cell. It has been observed that although open circuit voltage values for both type of cells do not differ much still, nanotube based dye-sensitized solar cells are more successful having an efficiency value of 7.28%.

Molecular and Nanoscale Engineering of High Efficiency Excitonic Solar Cells

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

Jenekhe, Samson A.; Ginger, David S.; Cao, Guozhong

We combined the synthesis of new polymers and organic-inorganic hybrid materials with new experimental characterization tools to investigate bulk heterojunction (BHJ) polymer solar cells and hybrid organic-inorganic solar cells during the 2007-2010 period (phase I) of this project. We showed that the bulk morphology of polymer/fullerene blend solar cells could be controlled by using either self-assembled polymer semiconductor nanowires or diblock poly(3-alkylthiophenes) as the light-absorbing and hole transport component. We developed new characterization tools in-house, including photoinduced absorption (PIA) spectroscopy, time-resolved electrostatic force microscopy (TR-EFM) and conductive and photoconductive atomic force microscopy (c-AFM and pc-AFM), and used them to investigatemore » charge transfer and recombination dynamics in polymer/fullerene BHJ solar cells, hybrid polymer-nanocrystal (PbSe) devices, and dye-sensitized solar cells (DSSCs); we thus showed in detail how the bulk photovoltaic properties are connected to the nanoscale structure of the BHJ polymer solar cells. We created various oxide semiconductor (ZnO, TiO 2) nanostructures by solution processing routes, including hierarchical aggregates and nanorods/nanotubes, and showed that the nanostructured photoanodes resulted in substantially enhanced light-harvesting and charge transport, leading to enhanced power conversion efficiency of dye-sensitized solar cells.« less

Nanostructured Materials for Solar Cells

NASA Technical Reports Server (NTRS)

Bailey, Sheila; Raffaelle, Ryne; Castro, Stephanie; Fahey, S.; Gennett, T.; Tin, P.

2003-01-01

The use of both inorganic and organic nanostructured materials in producing high efficiency photovoltaics is discussed in this paper. Recent theoretical results indicate that dramatic improvements in device efficiency may be attainable through the use of semiconductor quantum dots in an ordinary p-i-n solar cell. In addition, it has also recently been demonstrated that quantum dots can also be used to improve conversion efficiencies in polymeric thin film solar cells. A similar improvement in these types of cells has also been observed by employing single wall carbon nanotubes. This relatively new carbon allotrope may assist both in the disassociation of excitons as well as carrier transport through the composite material. This paper reviews the efforts that are currently underway to produce and characterize these nanoscale materials and to exploit their unique properties.

Effect of sintering time on the performance of turmeric dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Basuki, Hidajat, R. Lullus Lambang G.; Suyitno, Kristiawan, Budi; Rachmanto, Rendy Adhi

2017-01-01

This study reports the effect of sintering time on the performance of the dye-sensitized solar cells with turmeric dyes as sensitizers. Sintering TiO2 semiconductors were conducted at a temperature of 450°C for 30, 50, 90, 120, 150, and 180 minutes. The natural dye was extracted from dried turmeric powders with ethanol solvent. The results show that size of grains and the opening area of TiO2 semiconductor depended on the sintering time. The improvement of the properties of TiO2 semiconductor allowed more turmeric dyes were adsorbed by the semiconductors and then improved the performance of solar cells. The sintering time of 150 minutes produced large grains with an average diameter of 68.87 nm, and a porosity area of 26.51% caused the performance of DSSCs was the highest among other sintering time. The Voc, Jsc, and efficiency of DSSCs with turmeric-based natural dyes 0.64 V, 0.47 mA/cm2, and 0.2%, respectively.

Electronic structure measurements of metal-organic solar cell dyes using x-ray absorption spectroscopy

NASA Astrophysics Data System (ADS)

Johnson, Phillip S.

The focus of this thesis is twofold: to report the results of X-ray absorption studies of metal-organic dye molecules for dye-sensitized solar cells and to provide a basic training manual on X-ray absorption spectroscopy techniques and data analysis. The purpose of our research on solar cell dyes is to work toward an understanding of the factors influencing the electronic structure of the dye: the choice of the metal, its oxidation state, ligands, and cage structure. First we study the effect of replacing Ru in several common dye structures by Fe. First-principles calculations and X-ray absorption spectroscopy at the C 1s and N 1s edges are combined to investigate transition metal dyes in octahedral and square planar N cages. Octahedral molecules are found to have a downward shift in the N 1s-to-pi* transition energy and an upward shift in C 1s-to-pi* transition energy when Ru is replaced by Fe, explained by an extra transfer of negative charge from Fe to the N ligands compared to Ru. For the square planar molecules, the behavior is more complex because of the influence of axial ligands and oxidation state. Next the crystal field parameters for a series of phthalocyanine and porphyrins dyes are systematically determined using density functional calculations and atomic multiplet calculations with polarization-dependent X-ray absorption spectra. The polarization dependence of the spectra provides information on orbital symmetries which ensures the determination of the crystal field parameters is unique. A uniform downward scaling of the calculated crystal field parameters by 5-30% is found to be necessary to best fit the spectra. This work is a part of the ongoing effort to design and test new solar cell dyes. Replacing the rare metal Ru with abundant metals like Fe would be a significant advance for dye-sensitized solar cells. Understanding the effects of changing the metal centers in these dyes in terms of optical absorption, charge transfer, and electronic

Broadband energy transfer to sensitizing dyes by mobile quantum dot mediators in solar cells

PubMed Central

Adhyaksa, Gede Widia Pratama; Lee, Ga In; Baek, Se-Woong; Lee, Jung-Yong; Kang, Jeung Ku

2013-01-01

The efficiency of solar cells depends on absorption intensity of the photon collectors. Herein, mobile quantum dots (QDs) functionalized with thiol ligands in electrolyte are utilized into dye–sensitized solar cells. The QDs serve as mediators to receive and re–transmit energy to sensitized dyes, thus amplifying photon collection of sensitizing dyes in the visible range and enabling up–conversion of low-energy photons to higher-energy photons for dye absorption. The cell efficiency is boosted by dispersing QDs in electrolyte, thereby obviating the need for light scattering1 or plasmonic2 structures. Furthermore, optical spectroscopy and external quantum efficiency data reveal that resonance energy transfer due to the overlap between QD emission and dye absorption spectra becomes dominant when the QD bandgap is higher than the first excitonic peak of the dye, while co–sensitization resulting in a fast reduction of oxidized dyes is pronounced in the case of lower QD band gaps. PMID:24048384

From nanocorals to nanorods to nanoflowers nanoarchitecture for efficient dye-sensitized solar cells at relatively low film thickness: All Hydrothermal Process

NASA Astrophysics Data System (ADS)

Mali, Sawanta S.; Betty, Chirayath A.; Bhosale, Popatrao N.; Patil, Pramod S.; Hong, Chang Kook

2014-06-01

Simple and low temperature hydrothermal process is employed to synthesize exotic nanostructures of TiO2. The nanostructures are obtained merely by changing the nature of the precursors and processing parameters. The chloride and isopropoxide salts of titanium are used to grow high quality thin films comprising anatase nanocorals, rutile nanorods and rutile nanoflowers respectively. A novel route of addition of room temperature ionic liquid (RTIL) is used to synthesize hitherto unexplored nano-morphologies. The Bronsted Acidic Ionic Liquid [BAIL] 0.01 M, 1: 3-ethoxycarbonylethyl-1-methyl-imidazolium chloride [CMIM][HSO4] RTIL directed growth of TiO2 flowers with bunch of aligned nanorods are obtained. The structural, optical and morphological properties of hydrothermally grown TiO2 samples are studied with the different characterization techniques. The influence of these exotic nano-morphologies on the performance of dye sensitized solar cells (DSSCs) is investigated in detail. It is found that [CMIM][HSO4] can facilitate the formation of novel nanoflower morphology with uniform, dense, and collectively aligned in regular petal like oriented TiO2 nanorods and hence improves the dye adsorption and the photovoltaic performance of DSSCs, typically in short-circuit photocurrent and power conversion efficiency. A best power conversion efficiency of 6.63% has been achieved on a DSSC based on nanoflowers (TNF) film obtained from a [CMIM][HSO4] solution.

Synthesis of SnO_2 nanoparticles by electrooxidation of tin in quaternary ammonium salt for application in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Abrari, Masoud; Ghanaatshoar, Majid; Hosseiny Davarani, Saied Saeed; Moazami, Hamid Reza; Kazeminezhad, Iraj

2017-05-01

A facile synthetic route has been employed to prepare tin oxide nanoparticles. The route comprises anodic dissolution of metallic tin in the presence of tetramethylammonium chloride called electrooxidation. The effect of experimental parameters was investigated with special focus on solution pH. The obtained nanostructures have been characterized by XRD, EDS, TEM, FESEM, FTIR and UV-visible studies. The results show that the solution pH has a critical influence on the nanoparticles properties. The hydrophilic feature of nanoparticles decreases with pH growth, whereas their mean size increases. On the other hand, the size distribution is much uniform for the samples prepared at low pH. Having achieved the nanoparticles by electrooxidation, the dye-sensitized solar cells based on the produced SnO_2 nanoparticles were fabricated and the influence of nanoparticles on their performance was investigated. By variation in solution pH, we prepared nanoparticles with different particle sizes and photoanodes with various dye-loading abilities. The dye absorption and consequently current density of cells increased in acidic case, and therefore, power conversion efficiency grew up by 33% in acidic synthetic environment.

Co-sensitization of ruthenium(II) dye-sensitized solar cells by coumarin based dyes

NASA Astrophysics Data System (ADS)

Athanas, Anish Babu; Thangaraj, Shankar; Kalaiyar, Swarnalatha

2018-05-01

Co-sensitization technique has been appraised for attaining enhanced performance in dye-sensitized solar cells (DSSCs). DSSCs are fabricated with a heteroleptic Ru(II) sensitizer (RDAB1) containing 4,4‧-diamino-2,2‧-bipyridine (dabpy) ligand, co-sensitized with electron donor-acceptor type coumarin containing thiophene (CT) and indole (CI) moieties. The individual overall power conversion efficiency of the sensitizer is 5.44%. Enhanced power conversion efficiencies of 6.34% and 7.09% were observed when RDAB1 was co-sensitized with Coumarin containing CI and CT respectively. The enhanced PCE can be attributed to the presence of co-sensitizers which effectively overcome the light absorption by I-/I3-, dye aggregation and charge recombination.

Interfacial dynamics and solar fuel formation in dye-sensitized photoelectrosynthesis cells.

PubMed

Song, Wenjing; Chen, Zuofeng; Glasson, Christopher R K; Hanson, Kenneth; Luo, Hanlin; Norris, Michael R; Ashford, Dennis L; Concepcion, Javier J; Brennaman, M Kyle; Meyer, Thomas J

2012-08-27

Dye-sensitized photoelectrosynthesis cells (DSPECs) represent a promising approach to solar fuels with solar-energy storage in chemical bonds. The targets are water splitting and carbon dioxide reduction by water to CO, other oxygenates, or hydrocarbons. DSPECs are based on dye-sensitized solar cells (DSSCs) but with photoexcitation driving physically separated solar fuel half reactions. A systematic basis for DSPECs is available based on a modular approach with light absorption/excited-state electron injection, and catalyst activation assembled in integrated structures. Progress has been made on catalysts for water oxidation and CO(2) reduction, dynamics of electron injection, back electron transfer, and photostability under conditions appropriate for water splitting. With added reductive scavengers, as surrogates for water oxidation, DSPECs have been investigated for hydrogen generation based on transient absorption and photocurrent measurements. Detailed insights are emerging which define kinetic and thermodynamic requirements for the individual processes underlying DSPEC performance. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Molecular engineering of cyanine dyes to design a panchromatic response in Co-sensitized dye-sensitized solar cells

DOE PAGES

Pepe, Giulio; Cole, Jacqueline M.; Waddell, Paul G.; ...

2016-04-05

Cyanines are optically tunable dyes with high molar extinction coefficients, suitable for applications in co-sensitized dye-sensitized solar cells (DSCs); yet, barely thus applied. This might be due to the lack of a rational molecular design strategy that efficiently exploits cyanine properties. This study computationally re-designs these dyes, to broaden their optical absorption spectrum and create dye···TiO 2 binding and co-sensitization functionality. This is achieved via a stepwise molecular engineering approach. Firstly, the structural and optical properties of four parent dyes are experimentally and computationally investigated: 3,3’-diethyloxacarbocyanine iodide, 3,3’-diethylthiacarbocyanine iodide, 3,3’-diethylthiadicarbocyanine iodide and 3,3’-diethylthiatricarbocyanine iodide. Secondly, the molecules are theoretically modifiedmore » and their energetics are analyzed and compared to the parent dyes. A dye···TiO 2 anchoring group (carboxylic or cyanoacrylic acid), absent from the parent dyes, is chemically substituted at different molecular positions to investigate changes in optical absorption. We find that cyanoacrylic acid substitution at the para-quinoidal position affects the absorption wavelength of all parent dyes, with an optimal bathochromic shift of ca. 40 nm. The theoretical lengthening of the polymethine chain is also shown to effect dye absorption. Two molecularly engineered dyes are proposed as promising co-sensitizers. Finally, corresponding dye···TiO 2 adsorption energy calculations corroborate their applicability, demonstrating the potential of cyanine dyes in DSC research.« less

Broadband angle-independent antireflection coatings on nanostructured light trapping solar cells

NASA Astrophysics Data System (ADS)

Vázquez-Guardado, Abraham; Boroumand, Javaneh; Franklin, Daniel; Chanda, Debashis

2018-03-01

Backscattering from nanostructured surfaces greatly diminishes the efficacy of light trapping solar cells. While the analytical design of broadband, angle-independent antireflection coatings on nanostructured surfaces proved inefficient, numerical optimization proves a viable alternative. Here, we numerically design and experimentally verify the performance of single and bilayer antireflection coatings on a 2D hexagonal diffractive light trapping pattern on crystalline silicon substrates. Three well-known antireflection coatings, aluminum oxide, silicon nitride, and silicon oxide, which also double as high-quality surface passivation materials, are studied in the 400-1000 nm band. By varying thickness and conformity, the optimal parameters that minimize the broadband total reflectance (specular and scattering) from the nanostructured surface are obtained. The design results in a single-layer antireflection coating with normal-angle wavelength-integrated reflectance below 4% and a bilayer antireflection coating demonstrating reflection down to 1.5%. We show experimentally an angle-averaged reflectance of ˜5.2 % up to 60° incident angle from the optimized bilayer antireflection-coated nanostructured surface, paving the path toward practical implementation of the light trapping solar cells.

Nanostructured Electron-Selective Interlayer for Efficient Inverted Organic Solar Cells.

PubMed

Song, Jiyun; Lim, Jaehoon; Lee, Donggu; Thambidurai, M; Kim, Jun Young; Park, Myeongjin; Song, Hyung-Jun; Lee, Seonghoon; Char, Kookheon; Lee, Changhee

2015-08-26

We report a unique nanostructured electron-selective interlayer comprising of In-doped ZnO (ZnO:In) and vertically aligned CdSe tetrapods (TPs) for inverted polymer:fullerene bulkheterojunction (BHJ) solar cells. With dimension-controlled CdSe TPs, the direct inorganic electron transport pathway is provided, resulting in the improvement of the short circuit current and fill factor of devices. We demonstrate that the enhancement is attributed to the roles of CdSe TPs that reduce the recombination losses between the active layer and buffer layer, improve the hole-blocking as well as electron-transporting properties, and simultaneously improve charge collection characteristics. As a result, the power conversion efficiency of PTB7:PC70BM based solar cell with nanostructured CdSe TPs increases to 7.55%. We expect this approach can be extended to a general platform for improving charge extraction in organic solar cells.

Efficiencies of Dye-Sensitized Solar Cells using Ferritin-Encapsulated Quantum Dots with Various Staining Methods

NASA Astrophysics Data System (ADS)

Perez, Luis

Dye-sensitized solar cells (DSSC) have the potential to replace traditional and cost-inefficient crystalline silicon or ruthenium solar cells. This can only be accomplished by optimizing DSSC's energy efficiency. One of the major components in a dye-sensitized solar cell is the porous layer of titanium dioxide. This layer is coated with a molecular dye that absorbs sunlight. The research conducted for this paper focuses on the different methods used to dye the porous TiO2 layer with ferritin-encapsulated quantum dots. Multiple anodes were dyed using a method known as SILAR which involves deposition through alternate immersion in two different solutions. The efficiencies of DSSCs with ferritin-encapsulated lead sulfide dye deposited using SILAR were subsequently compared against the efficiencies produced by cells using the traditional immersion method. It was concluded that both methods resulted in similar efficiencies (? .074%) however, the SILAR method dyed the TiO2 coating significantly faster than the immersion method. On a related note, our experiments concluded that conducting 2 SILAR cycles yields the highest possible efficiency for this particular binding method. National Science Foundation.

Hydroxamate anchors for improved photoconversion in dye-sensitized solar cells.

PubMed

Brewster, Timothy P; Konezny, Steven J; Sheehan, Stafford W; Martini, Lauren A; Schmuttenmaer, Charles A; Batista, Victor S; Crabtree, Robert H

2013-06-03

We present the first analysis of performance of hydroxamate linkers as compared to carboxylate and phosphonate groups when anchoring ruthenium-polypyridyl dyes to TiO2 surfaces in dye-sensitized solar cells (DSSCs). The study provides fundamental insight into structure/function relationships that are critical for cell performance. Our DSSCs have been produced by using newly synthesized dye molecules and characterized by combining measurements and simulations of experimental current density-voltage (J-V) characteristic curves. We show that the choice of anchoring group has a direct effect on the overall sunlight-to-electricity conversion efficiency (η), with hydroxamate anchors showing the best performance. Solar cells based on the pyridyl-hydroxamate complex exhibit higher efficiency since they suppress electron transfer from the photoanode to the electrolyte and have superior photoinjection characteristics. These findings suggest that hydroxamate anchoring groups should be particularly valuable in DSSCs and photocatalytic applications based on molecular adsorbates covalently bound to semiconductor surfaces. In contrast, analogous acetylacetonate anchors might undergo decomposition under similar conditions suggesting limited potential in future applications.

Dye sensitized solar cell (DSSC) with natural dyes extracted from Jatropha leaves and purple Chrysanthemum flowers as sensitizer

NASA Astrophysics Data System (ADS)

Tahir, Dahlang; Satriani, Wilda; Gareso, P. L.; Abdullah, B.

2018-03-01

DSSC (Dye-Sensitized Solar Cell) prototype has been investigated using Jatropha leaves and purple Chrysanthemum flowers as natural dyes. DSSC consists of working electrode and counter electrode. A working electrode composed of semiconductor nanoparticles TiO2 that has been coated with dye molecules. Dye molecules serve as light photon catchers, while semiconductor nanoparticles TiO2 function to absorb and forward photons into electrons. In the electrode counter given catalyst carbon, serves to accelerate the reaction kinetics of triiodide reduction process on transparent conductive oxide (TCO). DSSC using TiO2 as a semiconductor material and natural dyes as sensitizer from Jatropha leaves and purple Chrysanthemum flowers are successful produced. The physical properties of the working electrode have been determined by using XRD and the chemical properties of the TiO2 powder and dye powder using FTIR and dye solution using UV-Vis. The resulted fabrications are also examined its I-V characteristics. The best performance is generated by mixed dye 1.91 x 10-3 % compared than those DSSC for dye extracted from Jatropha leaves or purple Chrysanthemum. The characterization results show that the higher of the absorption wavelength of the DSSC efficiency is high.

Investigating dye-sensitised solar cells

NASA Astrophysics Data System (ADS)

Tobin, Laura L.; O'Reilly, Thomas; Zerulla, Dominic; Sheridan, John T.

2010-05-01

At present there is considerable global concern in relation to environmental issues and future energy supplies, for instance climate change (global warming) and the rapid depletion of fossil fuel resources. This trepidation has initiated a more critical investigation into alternative and renewable sources of power such as geothermal, biomass, hydropower, wind and solar energy. The immense dependence on electrical power in today's society has prompted the manufacturing of devices such as photovoltaic (PV) cells to help alleviate and replace current electrical demands of the power grid. The most popular and commercially available PV cells are silicon solar cells which have to date the greatest efficiencies for PV cells. The drawback however is that the manufacturing of these cells is complex and costly due to the expense and difficulty of producing and processing pure silicon. One relatively inexpensive alternative to silicon PV cells that we are currently studying are dye-sensitised solar cells (DSSC or Grätzel Cells). DSSC are biomimetic solar cells which are based on the process of photosynthesis. The SFI Strategic Research Centre for Solar Energy Conversion is a research cluster based in Ireland formed with the express intention of bringing together industry and academia to produce renewable energy solutions. Our specific research area is in DSSC and their electrical properties. We are currently developing testing equipment for arrays of DSSC and developing optoelectronic models which todescribe the performance and behaviour of DSSCs.

A new strategy on utilizing nitrogen doped TiO{sub 2} in nanostructured solar cells: Embedded multifunctional N-TiO{sub 2} scattering particles in mesoporous photoanode

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

Shogh, Shiva; Mohammadpour, Raheleh; Iraji zad, Azam, E-mail: Iraji@sharif.edu

2015-12-15

Highlights: • N-doped TiO{sub 2} scattering particles were synthesized for embedding into commercial photoanode of dye sensitized solar cells. • Embedded scatterers improved optical and electrical features of the cells. • These multifunctional scatterers increased cell performance up to 17%. - Abstract: Aggregated sub-micron size nitrogen doped TiO{sub 2} (N-TiO{sub 2}) particles with superior optical and electrical features were successfully synthesized for embedding into commercial mesoporous TiO{sub 2} photoelectrode of dye sensitized solar cells (DSSCs) as the light scattering particles compared to undoped one. X-ray photoelectron spectroscopy and absorption spectra confirmed that the titanium dioxide is sufficiently doped by nitrogenmore » in N-TiO{sub 2} sample. Employing these high-surface N-TiO{sub 2} in mesoporous photoelectrode of solar cells, the power conversion efficiency of 8% has been achieved which shows 17% improvement for the optimum embedded level of doping (30 wt%) compared to commercial photoelectrode without additive; while enhanced efficiency is only 3% embedding undoped sub-micron size TiO{sub 2} particles. These results can introduce the novel multifunctional photoelectrode for nanostructured solar cells with enhanced values of scattering efficiency and improved electrical features including trap states density reduction in comparison to commercial mesoporous photoelectrodes.« less

Characteristics of the iodide/triiodide redox mediator in dye-sensitized solar cells.

PubMed

Boschloo, Gerrit; Hagfeldt, Anders

2009-11-17

Dye-sensitized solar cells (DSCs) have gained widespread interest because of their potential for low-cost solar energy conversion. Currently, the certified record efficiency of these solar cells is 11.1%, and measurements of their durability and stability suggest lifetimes exceeding 10 years under operational conditions. The DSC is a photoelectrochemical system: a monolayer of sensitizing dye is adsorbed onto a mesoporous TiO(2) electrode, and the electrode is sandwiched together with a counter electrode. An electrolyte containing a redox couple fills the gap between the electrodes. The redox couple is a key component of the DSC. The reduced part of the couple regenerates the photo-oxidized dye. The formed oxidized species diffuses to the counter electrode, where it is reduced. The photovoltage of the device depends on the redox couple because it sets the electrochemical potential at the counter electrode. The redox couple also affects the electrochemical potential of the TiO(2) electrode through the recombination kinetics between electrons in TiO(2) and oxidized redox species. This Account focuses on the special properties of the iodide/triiodide (I(-)/I(3)(-)) redox couple in dye-sensitized solar cells. It has been the preferred redox couple since the beginning of DSC development and still yields the most stable and efficient DSCs. Overall, the iodide/triiodide couple has good solubility, does not absorb too much light, has a suitable redox potential, and provides rapid dye regeneration. But what distinguishes I(-)/I(3)(-) from most redox mediators is the very slow recombination kinetics between electrons in TiO(2) and the oxidized part of the redox couple, triiodide. Certain dyes adsorbed at TiO(2) catalyze this recombination reaction, presumably by binding iodine or triiodide. The standard potential of the iodide/triiodide redox couple is 0.35 V (versus the normal hydrogen electrode, NHE), and the oxidation potential of the standard DSC-sensitizer (Ru(dcbpy)(2

Optical properties of anthocyanin dyes on TiO2 as photosensitizers for application of dye-sensitized solar cell (DSSC)

NASA Astrophysics Data System (ADS)

Ahliha, A. H.; Nurosyid, F.; Supriyanto, A.; Kusumaningsih, T.

2018-03-01

Dye-sensitized solar cell (DSSC) is one of the alternative energy that can convert light energy into electrical energy. The component of DSSC consists of FTO substrates, TiO2, electrolyte, dye sensitizer, and counter electrode. This study aim was to determine the effect of optical properties of anthocyanin dyes on efficiency of DSSC. The dye sensitizer used can be extracted from anthocyanin pigments such as dragon fruit, black rice, and red cabbage. The red cabbage sensitizer shows lower absorbance value in the visible range (450-580 nm), than dragon fruit and black rice. The chemical structure of each dye molecules has an R group (carbonyl and hydroxyl) that forms a bond with the oxide layer. Red cabbage dye cell has the highest efficiency, 0.06% then dragon fruit and black rice, 0.02% and 0.03%.

Benzo[a]carbazole-Based Donor-π-Acceptor Type Organic Dyes for Highly Efficient Dye-Sensitized Solar Cells.

PubMed

Qian, Xing; Zhu, Yi-Zhou; Chang, Wen-Ying; Song, Jian; Pan, Bin; Lu, Lin; Gao, Huan-Huan; Zheng, Jian-Yu

2015-05-06

A novel class of metal-free organic dyes based on benzo[a]carbazole have been designed, synthesized, and used in dye-sensitized solar cells for the first time. These types of dyes consisted of a cyanoacrylic acid moiety as the electron acceptor/anchoring group and different electron-rich spacers such as thiophene (JY21), furan (JY22), and oligothiophene (JY23) as the π-linkers. The photophysical, electrochemical, and photovoltaic properties, as well as theoretical calculations of these dyes were investigated. The photovoltaic performances of these dyes were found to be highly relevant to the π-conjugated linkers. In particular, dye JY23 exhibited a broad IPCE response with a photocurrent signal up to about 740 nm covering the most region of the UV-visible light. A DSSC based on JY23 showed the best photovoltaic performance with a Jsc of 14.8 mA cm(-2), a Voc of 744 mV, and a FF of 0.68, achieving a power conversion efficiency of 7.54% under standard AM 1.5 G irradiation.

Ultrafast Fabrication of Flexible Dye-Sensitized Solar Cells by Ultrasonic Spray-Coating Technology

PubMed Central

Han, Hyun-Gyu; Weerasinghe, Hashitha C.; Min Kim, Kwang; Soo Kim, Jeong; Cheng, Yi-Bing; Jones, David J.; Holmes, Andrew B.; Kwon, Tae-Hyuk

2015-01-01

This study investigates novel deposition techniques for the preparation of TiO2 electrodes for use in flexible dye-sensitized solar cells. These proposed new methods, namely pre-dye-coating and codeposition ultrasonic spraying, eliminate the conventional need for time-consuming processes such as dye soaking and high-temperature sintering. Power conversion efficiencies of over 4.0% were achieved with electrodes prepared on flexible polymer substrates using this new deposition technology and N719 dye as a sensitizer. PMID:26420466

Visible to near infra red absorption in natural dye (Mondo Grass Berry) for Dye Sensitized Solar Cell

NASA Astrophysics Data System (ADS)

Pitigala, Duleepa; Desilva, L. A. A.; Perera, A. G. U.

2012-03-01

The development of dye sensitized solar cells (DSSC) is an exciting field in the low cost renewable energy production. Two major draw backs in the DSSCs are the narrow spectral response and the short term stability. Research on development of artificial dyes for broadening the response is important in finding a solution. Work presented here shows a broad spectral response with a natural dye extracted from a Mondo Grass berry (Ophiopogonjaponicus).The dye is extracted by crushing the berries and filtering to remove the pulp. A DSSC sensitized with Mondo Grass dye, and with TiO2 film screen printed on a Florien doped Tin Oxide (FTO) glass and baked for 30 minutes at 450 C as the working electrode and Iodine/triiodide red-ox electrolyte as the hole collector was tested for its performance. An open circuit photovoltage of 495 mV and a short circuit photocurrent of 0.6 mA/cm2were observed under a simulated lamp equivalent to 1 sun illumination. The broad spectral response from 400 nm to 750 nm was also observed for the Mondo Grass dye compared to other natural dyes consists of anthocyanins or tannins.

Performance of dye sensitized solar cells (DSSC) using Syngonium Podophyllum Schott as natural dye and counter electrode

NASA Astrophysics Data System (ADS)

Oktariza, Lingga Ghufira; Yuliarto, Brian; Suyatman

2018-05-01

The extraction of chlorophyll pigment of Syngonium podophyllum Schott leaves which is used as natural dyes in this DSSC devices. The use of dye from nature with its simple production process is very effective to reduce DSSC production cost. Besides being used as a natural dye, chlorophyll can also be used as an alternative counter electrode. Chlorophyll that is used as a counter electrode has been through chemical activation and carbonization processes. The characterization were done using Uv-Vis, Cyclic Voltametry and DSSC device under solar simulator. Characterization of chlorophyll absorbance using UV-Vis has resulted in typical absorbance peak at visible light wavelength of 447 nm and 666 nm. The Tauc equation analysis of the Uv-Vis characterization showed 1.91 eV energy gap of chlorophyll. Chlorophyll carbonized dye is used as an alternative to Pt counter electrode. Carbonized chlorophyll dye resulted in lower conversion efficiency of 0.308% with HSE electrolyte.

Effect of photoanode thickness on electrochemical performance of dye sensitized solar cell

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

Khatani, Mehboob, E-mail: mkhatani@hotmail.com; Hamid, Nor Hisham, E-mail: hishmid@petronas.com.my; Sahmer, Ahmed Zahrin, E-mail: azclement@yahoo.com

2015-07-22

The thickness of photoanode is crucial as it adsorbed a large amount of dye molecules that provide electrons for generation of electricity in dye sensitized solar cell (DSC). Thus, in order to realize the practical application of DSC, study on various thickness of photoanode need to be carried out to analyze its effect on the electrochemical behavior of dye sensitized solar cell. To enhance the conversion efficiency, an additional layer of TiO{sub 2} using TiCl{sub 4} treatment was deposited prior to the deposition of the photoanode (active area of 1cm{sup 2}) with the thickness of 6, 12, 18, 24, andmore » 30 µm on fluorine doped tin oxide (FTO) glass substrate. The resulting photoanode after the soak in N719 dye for more than 12hrs were used to be assembled in a test cell in combination with liquid electrolyte and counter electrode. The fabricated cells were characterized by solar simulator, ultraviolet-visible spectroscopy (UV-VIS), and electrochemical impedance spectroscopy (EIS). Scanning electron microscopy (SEM) was used to approximate the thickness of photoanode. An optimum power conversion efficiency of 4.54% was obtained for the cell fabricated with 18 µm photoanode thickness. This is attributed to the reduced resistance related to electron transport in the TiO{sub 2}/dye/electrolyte interface as proven by the EIS result. This led to the reduction of internal resistance, the increase in the electron life time and the improvement in the conversion efficiency.« less

Synthesis and characterization of Allium cepa L. as photosensitizer of dye-sensitized solar cell

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

Sutikno, E-mail: smadnasri@yahoo.com; Afrian, Noverdi; Supriadi,

The synthesis and characterization of Allium cepa L. used as natural pigment for natural dye sensitizer of solar cell has successfully done and anthocyanin is extracted. Anthocynin is color pigment of plant which has characteristic absorption spectrum of photon and excites electrons up to pigment molecules. As the anthocyanin absorbed light increases the excited electrons increase as well. The generated current also increases and it leads to the efficiency increase. The energy conversion efficiency of the cells sensitized with dye of Allium cepa L. was 3,045 x 10{sup −4}%. A simple technique was taken to fabricate dye sensitizer solar cellmore » is spincoating.« less

Dye adsorption mechanisms in TiO2 films, and their effects on the photodynamic and photovoltaic properties in dye-sensitized solar cells.

PubMed

Hwang, Kyung-Jun; Shim, Wang-Geun; Kim, Youngjin; Kim, Gunwoo; Choi, Chulmin; Kang, Sang Ook; Cho, Dae Won

2015-09-14

The adsorption mechanism for the N719 dye on a TiO2 electrode was examined by the kinetic and diffusion models (pseudo-first order, pseudo-second order, and intra-particle diffusion models). Among these methods, the observed adsorption kinetics are well-described using the pseudo-second order model. Moreover, the film diffusion process was the main controlling step of adsorption, which was analysed using a diffusion-based model. The photodynamic properties in dye-sensitized solar cells (DSSCs) were investigated using time-resolved transient absorption techniques. The photodynamics of the oxidized N719 species were shown to be dependent on the adsorption time, and also the adsorbed concentration of N719. The photovoltaic parameters (Jsc, Voc, FF and η) of this DSSC were determined in terms of the dye adsorption amounts. The solar cell performance correlates significantly with charge recombination and dye regeneration dynamics, which are also affected by the dye adsorption amounts. Therefore, the photovoltaic performance of this DSSC can be interpreted in terms of the adsorption kinetics and the photodynamics of oxidized N719.

Influence of polar solvents on photovoltaic performance of Monascusred dye-sensitized solar cell

NASA Astrophysics Data System (ADS)

Lee, Jae Wook; Kim, Tae Young; Ko, Hyun Seok; Han, Shin; Lee, Suk-Ho; Park, Kyung Hee

Dye-sensitized solar cells (DSSCs) were assembled using natural dyes extracted from Monascus red pigment as a sensitizer. In this work, we studied the adsorption characteristics for harvesting sunlight and the electrochemical behavior for electron transfer in Monascus red DSSC using different solvents. The effect of polar aprotic and protic solvents including water, ethanol, and dimethylsulfoxide (DMSO) used in the sensitization process was investigated for the improvement in conversion efficiency of a cell. As for the Monascus red dye-sensitized electrode in DMSO solvent, the solar cell yields a short-circuit current density (Jsc) of 1.23 mA/cm2, a photovoltage (Voc) of 0.75 V, and a fill factor of 0.72, corresponding to an energy conversion efficiency (η) of 0.66%.

Concrete Embedded Dye-Synthesized Photovoltaic Solar Cell

PubMed Central

Hosseini, T.; Flores-Vivian, I.; Sobolev, K.; Kouklin, N.

2013-01-01

This work presents the concept of a monolithic concrete-integrated dye-synthesized photovoltaic solar cell for optical-to-electrical energy conversion and on-site power generation. The transport measurements carried out in the dark revealed the presence of VOC of ~190 mV and ISC of ~9 μA, induced by the electrochemical conversion of concrete-supplied ionic impurities at the electrodes. The current-voltage measurements performed under illumination at incident optical powers of ~46 mW confirmed the generation of electrical power of ~0.64 μW with almost half generated via battery effect. This work presents a first step towards realizing the additional pathways to low-cost electrical power production in urban environments based on a combined use of organic dyes, nanotitania and concrete technology. PMID:24067664

Hydrothermal growth and characterization of titanium dioxide nanostructures for use in dye sensitized solar cells

NASA Astrophysics Data System (ADS)

Sorge, Judith D.

As the world's energy needs continue to grow, next generation photovoltaic cells are in high demand because they offer the possibility of an inexpensive alternative to current energy production techniques. Dye sensitized solar cells (DSSC's), utilize common materials and low cost commercialization techniques, which make them a compelling choice for research in this area. This research focuses on the titanium dioxide coating, which transfers electrons from the photoactive dye to the electrode. 3-4% efficient DSSC's using doctor bladed titanium dioxide coatings with a specific surface area of 55-60m2/g have been demonstrated in our laboratory. To enhance the efficiency of these cells, both the surface area and the electron conduction of the titania layer must be optimized. This has been done by utilizing high aspect ratio nanoparticles of titania instead of mesoporous layers formed with spherical particles. Anodization of titanium metal or anodic alumina membrane templating are common ways to produce nanorods, but involve complex processes leading toward expensive commercialization. This research instead focuses on the hydrothermal growth of nanofibrous titania on a titanium metal substrate, removing the need for dispersion and deposition procedures as well as using a low temperature processing method. Depending upon the formulation utilized, a variety of structures can be produced, from thick carpets of nanofiber strands to large platelets. The composition and morphology of the products have been characterized with respect to the growth conditions using electron microscopy, energy dispersive spectroscopy and x-ray diffraction. The compositional analysis is used to investigate the complicated reaction mechanisms in the system. Coatings of titania nanotubes were then tested in the DSSC's, as were those with the titanium metal substrate acting as the photo anode. Modeling the geometric parameters of the different pore structures of the coatings helps us to understand

High-performance Förster resonance energy transfer (FRET)-based dye-sensitized solar cells: rational design of quantum dots for wide solar-spectrum utilization.

PubMed

Lee, Eunwoo; Kim, Chanhoi; Jang, Jyongsik

2013-07-29

High-performance Förster resonance energy transfer (FRET)-based dye-sensitized solar cells (DSSCs) have been successfully fabricated through the optimized design of a CdSe/CdS quantum-dot (QD) donor and a dye acceptor. This simple approach enables quantum dots and dyes to simultaneously utilize the wide solar spectrum, thereby resulting in high conversion efficiency over a wide wavelength range. In addition, major parameters that affect the FRET interaction between donor and acceptor have been investigated including the fluorescent emission spectrum of QD, and the content of deposited QDs into the TiO2 matrix. By judicious control of these parameters, the FRET interaction can be readily optimized for high photovoltaic performance. In addition, the as-synthesized water-soluble quantum dots were highly dispersed in a nanoporous TiO2 matrix, thereby resulting in excellent contact between donors and acceptors. Importantly, high-performance FRET-based DSSCs can be prepared without any infrared (IR) dye synthetic procedures. This novel strategy offers great potential for applications of dye-sensitized solar cells. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Molecular engineering of fluorescein dyes as complementary absorbers in dye co-sensitized solar cells

DOE PAGES

Pepe, Giulio; Cole, Jacqueline M.; Waddell, Paul G.; ...

2016-09-22

Fluorescein dye derivatives exhibit extended optical absorption up to 500 nm, rendering these compounds suitable as co-absorbers in dye-sensitized solar cells (DSCs). A molecular engineering approach is presented, which embraces this intrinsic optical attribute of fluoresceins, while modifying the dye chemistry to enhance their light harvesting efficiency, in order to effectively tailor them for DSC applications. This approach first realizes relationships between the molecular structure and the optoelectronic properties for a series of five a priori known (parent) fluorescein dyes: 5-carboxyfluorescein (1), a mixture of m-carboxyfluorescein where m = 5 or 6 (2), 5-carboxyfluorescein diacetate (3), 6-carboxyfluorescein diacetate (4), amore » mixture of n-carboxy-2',7'-dichlorofluorescein diacetate where n = 5 or 6 (5). The first step in this approach combines, where available, experimental and computational methods so that electronic structure calculations can also be validated for representative fluorescein dyes. Such calculations can then be used reliably to predict the structure and properties of fluorescein dyes for cases where experimental data are lacking. Structure-function relationships established from this initial step inform the selection of parent dye 1 that is taken forward to the second step in molecular engineering: in silico chemical derivation to re-functionalize 1 for DSC applications. For this purpose, computational calculations are used to extend the charge conjugation in 1 between its donor and acceptor moieties. These structural modifications result in a bathochromic shift of the lowest excitation by ~1.3-1.9 eV (100-170 nm), making the dye optically absorb in the visible region. Further calculations on dye molecules adsorbed onto the surface of a TiO 2 cluster are used to investigate the dye sensitization behavior via dye adsorption energies and anchoring modes. The results of this theoretical investigation lead to two molecularly engineered

Molecular engineering of fluorescein dyes as complementary absorbers in dye co-sensitized solar cells

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

Pepe, Giulio; Cole, Jacqueline M.; Waddell, Paul G.

Fluorescein dye derivatives exhibit extended optical absorption up to 500 nm, rendering these compounds suitable as co-absorbers in dye-sensitized solar cells (DSCs). A molecular engineering approach is presented, which embraces this intrinsic optical attribute of fluoresceins, while modifying the dye chemistry to enhance their light harvesting efficiency, in order to effectively tailor them for DSC applications. This approach first realizes relationships between the molecular structure and the optoelectronic properties for a series of five a priori known (parent) fluorescein dyes: 5-carboxyfluorescein (1), a mixture of m-carboxyfluorescein where m = 5 or 6 (2), 5-carboxyfluorescein diacetate (3), 6-carboxyfluorescein diacetate (4), amore » mixture of n-carboxy-2',7'-dichlorofluorescein diacetate where n = 5 or 6 (5). The first step in this approach combines, where available, experimental and computational methods so that electronic structure calculations can also be validated for representative fluorescein dyes. Such calculations can then be used reliably to predict the structure and properties of fluorescein dyes for cases where experimental data are lacking. Structure-function relationships established from this initial step inform the selection of parent dye 1 that is taken forward to the second step in molecular engineering: in silico chemical derivation to re-functionalize 1 for DSC applications. For this purpose, computational calculations are used to extend the charge conjugation in 1 between its donor and acceptor moieties. These structural modifications result in a bathochromic shift of the lowest excitation by ~1.3-1.9 eV (100-170 nm), making the dye optically absorb in the visible region. Further calculations on dye molecules adsorbed onto the surface of a TiO 2 cluster are used to investigate the dye sensitization behavior via dye adsorption energies and anchoring modes. The results of this theoretical investigation lead to two molecularly engineered

Multilayer Dye Aggregation at Dye/TiO2 Interface via π…π Stacking and Hydrogen Bond and Its Impact on Solar Cell Performance: A DFT Analysis.

PubMed

Zhang, Lei; Liu, Xiaogang; Rao, Weifeng; Li, Jingfa

2016-10-21

Multilayer dye aggregation at the dye/TiO 2 interface of dye-sensitized solar cells is probed via first principles calculations, using p-methyl red azo dye as an example. Our calculations suggest that the multilayer dye aggregates at the TiO 2 surface can be stabilized by π…π stacking and hydrogen bond interactions. Compared with previous two-dimensional monolayer dye/TiO 2 model, the multilayer dye aggregation model proposed in this study constructs a three-dimensional multilayer dye/TiO 2 interfacial structure, and provides a better agreement between experimental and computational results in dye coverage and dye adsorption energy. In particular, a dimer forms by π…π stacking interactions between two neighboring azo molecules, while one of them chemisorbs on the TiO 2 surface; a trimer may form by introducing one additional azo molecule on the dimer through a hydrogen bond between two carboxylic acid groups. Different forms of multilayer dye aggregates, either stabilized by π…π stacking or hydrogen bond, exhibit varied optical absorption spectra and electronic properties. Such variations could have a critical impact on the performance of dye sensitized solar cells.

Multilayer Dye Aggregation at Dye/TiO2 Interface via π…π Stacking and Hydrogen Bond and Its Impact on Solar Cell Performance: A DFT Analysis

PubMed Central

Zhang, Lei; Liu, Xiaogang; Rao, Weifeng; Li, Jingfa

2016-01-01

Multilayer dye aggregation at the dye/TiO2 interface of dye-sensitized solar cells is probed via first principles calculations, using p-methyl red azo dye as an example. Our calculations suggest that the multilayer dye aggregates at the TiO2 surface can be stabilized by π…π stacking and hydrogen bond interactions. Compared with previous two-dimensional monolayer dye/TiO2 model, the multilayer dye aggregation model proposed in this study constructs a three-dimensional multilayer dye/TiO2 interfacial structure, and provides a better agreement between experimental and computational results in dye coverage and dye adsorption energy. In particular, a dimer forms by π…π stacking interactions between two neighboring azo molecules, while one of them chemisorbs on the TiO2 surface; a trimer may form by introducing one additional azo molecule on the dimer through a hydrogen bond between two carboxylic acid groups. Different forms of multilayer dye aggregates, either stabilized by π…π stacking or hydrogen bond, exhibit varied optical absorption spectra and electronic properties. Such variations could have a critical impact on the performance of dye sensitized solar cells. PMID:27767196

Magnetron sputtering in the creation of photonic nanostructures derived from Sasakia Charonda Formosana-butterfly wings for applied in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Niu, Haihong; Zhou, Ru; Cheng, Cong; Zhang, Gonghai; Hu, Yu; Huang, Bin; Zhang, Shouwei; Shang, Xin; Xia, Mei; Xu, Jinzhang

2016-09-01

Creating new functional materials derived from the structures seen on butterfly wings has achieved interest in a variety of research topics. However, there need a concision approach could result in a high-quality, precise, and convenient process for the fabrication of complex nanostructures replication with unique functionalities based on the butterfly wings. Here we developed a pithy approach based on a magnetron sputtering metal Ti process for biotemplating used to refine hierarchically porous titanium dioxide photonic crystal nanostructures (TiO2sbnd PCN), themselves derived from nanostructures present on the wings of Sasakia Charonda Formosana (S. Charonda) butterflies. For the first time, the TiO2sbnd PCN were deposited on the top of the P25 active layer and were used to fabricate DSSCs as the light-scattering layers of photoanodes with power conversion efficiencies of up to 8.7%. Remarkably, a much enhanced photocurrent density and a prominent photoelectrochemical conversion capability have been achieved, which are exceeding most of the previously reported photoanodes as well as a similar butterflies replication-based device structure. Our study suggests many exciting opportunities of developing artificially engineered butterfly wing-based solar-to-fuel conversion.

Optimizing Ionic Electrolytes for Dye-Sensitized Solar Cells

NASA Astrophysics Data System (ADS)

Fan, Xiaojuan; Hall, Sarah

2009-03-01

Dye-sensitized solar cells DSSCs provide next generation, low cost, and easy fabrication photovoltaic devices based on organic sensitizing molecules, polymer gel electrolyte, and metal oxide semiconductors. One of the key components is the solvent-free ionic liquid electrolyte that has low volatility and high stability. We report a rapid and low cost method to fabricate ionic polymer electrolyte used in DSSCs. Poly(ethylene oxide) (PEO) is blended with imidazolinium salt without any chemical solvent to form a gel electrolyte. Uniform and crack-free porous TiO2 thin films are sensitized by porphrine dye covered by the synthesized gel electrolyte. The fabricated DSSCs are more stable and potentially increase the photo-electricity conversion efficiency.

Digital Printing of Titanium Dioxide for Dye Sensitized Solar Cells.

PubMed

Cherrington, Ruth; Wood, Benjamin Michael; Salaoru, Iulia; Goodship, Vannessa

2016-05-04

Silicon solar cell manufacturing is an expensive and high energy consuming process. In contrast, dye sensitized solar cell production is less environmentally damaging with lower processing temperatures presenting a viable and low cost alternative to conventional production. This paper further enhances these environmental credentials by evaluating the digital printing and therefore additive production route for these cells. This is achieved here by investigating the formation and performance of a metal oxide photoelectrode using nanoparticle sized titanium dioxide. An ink-jettable material was formulated, characterized and printed with a piezoelectric inkjet head to produce a 2.6 µm thick layer. The resultant printed layer was fabricated into a functioning cell with an active area of 0.25 cm(2) and a power conversion efficiency of 3.5%. The binder-free formulation resulted in a reduced processing temperature of 250 °C, compatible with flexible polyamide substrates which are stable up to temperatures of 350 ˚C. The authors are continuing to develop this process route by investigating inkjet printing of other layers within dye sensitized solar cells.

Digital Printing of Titanium Dioxide for Dye Sensitized Solar Cells

PubMed Central

Cherrington, Ruth; Wood, Benjamin Michael; Salaoru, Iulia; Goodship, Vannessa

2016-01-01

Silicon solar cell manufacturing is an expensive and high energy consuming process. In contrast, dye sensitized solar cell production is less environmentally damaging with lower processing temperatures presenting a viable and low cost alternative to conventional production. This paper further enhances these environmental credentials by evaluating the digital printing and therefore additive production route for these cells. This is achieved here by investigating the formation and performance of a metal oxide photoelectrode using nanoparticle sized titanium dioxide. An ink-jettable material was formulated, characterized and printed with a piezoelectric inkjet head to produce a 2.6 µm thick layer. The resultant printed layer was fabricated into a functioning cell with an active area of 0.25 cm2 and a power conversion efficiency of 3.5%. The binder-free formulation resulted in a reduced processing temperature of 250 °C, compatible with flexible polyamide substrates which are stable up to temperatures of 350 ˚C. The authors are continuing to develop this process route by investigating inkjet printing of other layers within dye sensitized solar cells. PMID:27166761

Nanostructured refractory thin films for solar applications

NASA Astrophysics Data System (ADS)

Ollier, E.; Dunoyer, N.; Dellea, O.; Szambolics, H.

2014-08-01

Selective solar absorbers are key elements of all solar thermal systems. Solar thermal panels and Concentrated Solar Power (CSP) systems aim respectively at producing heat and electricity. In both cases, a surface receives the solar radiation and is designed to have the highest optical absorption (lowest optical reflectivity) of the solar radiation in the visible wavelength range where the solar intensity is the highest. It also has a low emissivity in the infrared (IR) range in order to avoid radiative thermal losses. Current solutions in the state of the art usually consist in deposited interferential thin films or in cermets [1]. Structured surfaces have been proposed and have been simulated because they are supposed to be more efficient when the solar radiation is not normal to the receiving surface and because they could potentially be fabricated with refractory materials able to sustain high operating temperatures. This work presents a new method to fabricate micro/nanostructured surfaces on molybdenum (refractory metal with a melting temperature of 2623°C). This method now allows obtaining a refractory selective surface with an excellent optical selectivity and a very high absorption in the visible range. This high absorption performance was obtained by achieving a double structuration at micro and nano scales thanks to an innovative process flow.

Photovoltaic characteristics of natural light harvesting dye sensitized solar cells

NASA Astrophysics Data System (ADS)

Hafez, H. S.; Shenouda, S. S.; Fadel, M.

2018-03-01

In this work of research, anthocyanin as a natural dye obtained from raspberry fruits, was used and tested as a photon harvesting/electron donating dye in titanium dioxide nanoparticle-based DSSCs. A working photoelectrode made from TiO2 nanoparticles with an average particle size (10-40 nm) that is coated on Florine doped tin-oxide substrate, was prepared via a simple and low cost hydrothermal method. A detailed structural and morphological analysis of the TiO2 photoactive electrode was investigated by X-ray diffraction (XRD), diffuse reflectance spectrometer, transmission electron microscope (TEM) and scanning electron microscope (SEM). Complete photovoltaic characteristics including (current, voltage, outpower, and responsivity) of the natural anthocyanin based dye sensitized solar cell have been investigated under different illumination intensity ranging from 10 to 100 mW.cm- 2. The cell responsivity and efficiency of the fabricated solar cell under different illumination intensity were found to be in the range (R = 15.6-23.8 mA.W- 1 and η = 0.13-0.25) at AM = 1.5 conditions. This study is important for enhancing the future applications of the promising DSSC technology.

Photovoltaic characteristics of natural light harvesting dye sensitized solar cells.

PubMed

Hafez, H S; Shenouda, S S; Fadel, M

2018-03-05

In this work of research, anthocyanin as a natural dye obtained from raspberry fruits, was used and tested as a photon harvesting/electron donating dye in titanium dioxide nanoparticle-based DSSCs. A working photoelectrode made from TiO 2 nanoparticles with an average particle size (10-40nm) that is coated on Florine doped tin-oxide substrate, was prepared via a simple and low cost hydrothermal method. A detailed structural and morphological analysis of the TiO 2 photoactive electrode was investigated by X-ray diffraction (XRD), diffuse reflectance spectrometer, transmission electron microscope (TEM) and scanning electron microscope (SEM). Complete photovoltaic characteristics including (current, voltage, outpower, and responsivity) of the natural anthocyanin based dye sensitized solar cell have been investigated under different illumination intensity ranging from 10 to 100mW.cm -2 . The cell responsivity and efficiency of the fabricated solar cell under different illumination intensity were found to be in the range (R=15.6-23.8mA.W -1 and η=0.13-0.25) at AM=1.5 conditions. This study is important for enhancing the future applications of the promising DSSC technology. Copyright © 2017 Elsevier B.V. All rights reserved.

Photoanode Thickness Optimization and Impedance Spectroscopic Analysis of Dye-Sensitized Solar Cells based on a Carbazole-Containing Ruthenium Dye

NASA Astrophysics Data System (ADS)

Choi, Jongwan; Kim, Felix Sunjoo

2018-03-01

We studied the influence of photoanode thickness on the photovoltaic characteristics and impedance responses of the dye-sensitized solar cells based on a ruthenium dye containing a hexyloxyl-substituted carbazole unit (Ru-HCz). As the thickness of photoanode increases from 4.2 μm to 14.8 μm, the dye-loading amount and the efficiency increase. The device with thicker photoanode shows a decrease in the efficiency due to the higher probability of recombination of electron-hole pairs before charge extraction. We also analyzed the electron-transfer and recombination characteristics as a function of photoanode thickness through detailed electrochemical impedance spectroscopy analysis.

Influence of polar solvents on photovoltaic performance of Monascusred dye-sensitized solar cell.

PubMed

Lee, Jae Wook; Kim, Tae Young; Ko, Hyun Seok; Han, Shin; Lee, Suk-Ho; Park, Kyung Hee

2014-05-21

Dye-sensitized solar cells (DSSCs) were assembled using natural dyes extracted from Monascus red pigment as a sensitizer. In this work, we studied the adsorption characteristics for harvesting sunlight and the electrochemical behavior for electron transfer in Monascus red DSSC using different solvents. The effect of polar aprotic and protic solvents including water, ethanol, and dimethylsulfoxide (DMSO) used in the sensitization process was investigated for the improvement in conversion efficiency of a cell. As for the Monascus red dye-sensitized electrode in DMSO solvent, the solar cell yields a short-circuit current density (Jsc) of 1.23mA/cm(2), a photovoltage (Voc) of 0.75V, and a fill factor of 0.72, corresponding to an energy conversion efficiency (η) of 0.66%. Copyright © 2014 Elsevier B.V. All rights reserved.

Ultrasonically facilitated adsorption of an azo dye onto nanostructures obtained from cellulosic wastes of broom and cooler straw.

PubMed

Safari, Mahdi; Khataee, Alireza; Darvishi Cheshmeh Soltani, Reza; Rezaee, Reza

2018-07-15

In the present work, ultrasonically facilitated adsorption (UFA) of a cationic dye [Basic Red 46 (BR46)] was examined using cellulosic nanostructures obtained from broom and cooler straw. Although the exclusive application of the nanostructured broom resulted in the 43.51% adsorption of BR46, the UFA process gave rise to the substantial removal efficiency of about 93%. In the case of the nanostructured straw, the efficiency was increased from 36.9% to 55.7%. The UFA process for both adsorbents reached the equilibrium within 60 min which was shorter than the time for the only adsorption. According to the values of the mean free energy (E), the decolorization via the UFA process applying broom (15.81 kJ/mol) and straw (11.18 kJ/mol) nanostructures was occurred chemically. An insignificant loss in the adsorption capacity of both adsorbents was observed after three regeneration tests by means of 0.05 M hydrochloric acid, indicating the good reusability potential of the as-synthesized cellulosic nanostructures. Copyright © 2018 Elsevier Inc. All rights reserved.

Rapid Synthesis of Thiophene-Based, Organic Dyes for Dye-Sensitized Solar Cells (DSSCs) by a One-Pot, Four-Component Coupling Approach.

PubMed

Matsumura, Keisuke; Yoshizaki, Soichi; Maitani, Masato M; Wada, Yuji; Ogomi, Yuhei; Hayase, Shuzi; Kaiho, Tatsuo; Fuse, Shinichiro; Tanaka, Hiroshi; Takahashi, Takashi

2015-06-26

This one-pot, four-component coupling approach (Suzuki-Miyaura coupling/C-H direct arylation/Knoevenagel condensation) was developed for the rapid synthesis of thiophene-based organic dyes for dye-sensitized solar cells (DSSCs). Seven thiophene-based, organic dyes of various donor structures with/without the use of a 3,4-ethylenedioxythiophene (EDOT) moiety were successfully synthesized in good yields based on a readily available thiophene boronic acid pinacol ester scaffold (one-pot, 3-step, 35-61%). Evaluation of the photovoltaic properties of the solar cells that were prepared using the synthesized dyes revealed that the introduction of an EDOT structure beside a cyanoacrylic acid moiety improved the short-circuit current (Jsc) while decreasing the fill factor (FF). The donor structure significantly influenced the open-circuit voltage (Voc), the FF, and the power conversion efficiency (PCE). The use of a n-hexyloxyphenyl amine donor, and our originally developed, rigid, and nonplanar donor, both promoted good cell performance (η=5.2-5.6%). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Efficient platinum-free counter electrodes for dye-sensitized solar cell applications.

PubMed

Ahmad, Shahzada; Yum, Jun-Ho; Butt, Hans-Jürgen; Nazeeruddin, Mohammad K; Grätzel, Michael

2010-09-10

Nanoporous layers of poly(3,4-propylenedioxythiophene) (PProDOT) were fabricated by electrical-field-assisted growth using hydrophobic ionic liquids as the growing medium. A series of PProDoT layers was prepared with three different ionic liquids to control the microstructure and electrochemical properties of the resulting dye-sensitized solar cells, which were highly efficient and showed a power conversion efficiency of >9% under different sunlight intensities. The current-voltage characteristics of the counter electrodes varied depending on the ionic liquids used in the synthesis of PProDOT. The most hydrophobic ionic liquids exhibited high catalytic properties, thus resulting in high power conversion efficiency and allowing the fabrication of platinum-free, stable, flexible, and cost-effective dye-sensitized solar cells.

Conditions for diffusion-limited and reaction-limited recombination in nanostructured solar cells

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

Ansari-Rad, Mehdi, E-mail: ansari.rad@ut.ac.ir; Department of Physics, University of Shahrood, Shahrood; Anta, Juan A., E-mail: anta@upo.es

2014-04-07

The performance of Dye-sensitized solar cells (DSC) and related devices made of nanostructured semiconductors relies on a good charge separation, which in turn is achieved by favoring charge transport against recombination. Although both processes occur at very different time scales, hence ensuring good charge separation, in certain cases the kinetics of transport and recombination can be connected, either in a direct or an indirect way. In this work, the connection between electron transport and recombination in nanostructured solar cells is studied both theoretically and by Monte Carlo simulation. Calculations using the Multiple-Trapping model and a realistic trap distribution for nanostructuredmore » TiO{sub 2} show that for attempt-to-jump frequencies higher than 10{sup 11}–10{sup 13} Hz, the system adopts a reaction limited (RL) regime, with a lifetime which is effectively independent from the speed of the electrons in the transport level. For frequencies lower than those, and depending on the concentration of recombination centers in the material, the system enters a diffusion-limited regime (DL), where the lifetime increases if the speed of free electrons decreases. In general, the conditions for RL or DL recombination depend critically on the time scale difference between recombination kinetics and free-electron transport. Hence, if the former is too rapid with respect to the latter, the system is in the DL regime and total thermalization of carriers is not possible. In the opposite situation, a RL regime arises. Numerical data available in the literature, and the behavior of the lifetime with respect to (1) density of recombination centers and (2) probability of recombination at a given center, suggest that a typical DSC in operation stays in the RL regime with complete thermalization, although a transition to the DL regime may occur for electrolytes or hole conductors where recombination is especially rapid or where there is a larger dispersion of

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.

Peripheral Hole Acceptor Moieties on an Organic Dye Improve Dye‐Sensitized Solar Cell Performance

PubMed Central

Hao, Yan; Gabrielsson, Erik; Lohse, Peter William; Yang, Wenxing; Johansson, Erik M. J.; Hagfeldt, Anders

2015-01-01

Investigation of charge transfer dynamics in dye‐sensitized solar cells is of fundamental interest and the control of these dynamics is a key factor for developing more efficient solar cell devices. One possibility for attenuating losses through recombination between injected electrons and oxidized dye molecules is to move the positive charge further away from the metal oxide surface. For this purpose, a metal‐free dye named E6 is developed, in which the chromophore core is tethered to two external triphenylamine (TPA) units. After photoinduced electron injection into TiO2, the remaining hole is rapidly transferred to a peripheral TPA unit. Electron–hole recombination is slowed down by 30% compared to a reference dye without peripheral TPA units. Furthermore, it is found that the added TPA moieties improve the electron blocking effect of the dye, retarding recombination of electrons from TiO2 to the cobalt‐based electrolyte. PMID:27722076

In silico designing of power conversion efficient organic lead dyes for solar cells using todays innovative approaches to assure renewable energy for future

NASA Astrophysics Data System (ADS)

Kar, Supratik; Roy, Juganta K.; Leszczynski, Jerzy

2017-06-01

Advances in solar cell technology require designing of new organic dye sensitizers for dye-sensitized solar cells with high power conversion efficiency to circumvent the disadvantages of silicon-based solar cells. In silico studies including quantitative structure-property relationship analysis combined with quantum chemical analysis were employed to understand the primary electron transfer mechanism and photo-physical properties of 273 arylamine organic dyes from 11 diverse chemical families explicit to iodine electrolyte. The direct quantitative structure-property relationship models enable identification of the essential electronic and structural attributes necessary for quantifying the molecular prerequisites of 11 classes of arylamine organic dyes, responsible for high power conversion efficiency of dye-sensitized solar cells. Tetrahydroquinoline, N,N'-dialkylaniline and indoline have been least explored classes under arylamine organic dyes for dye-sensitized solar cells. Therefore, the identified properties from the corresponding quantitative structure-property relationship models of the mentioned classes were employed in designing of "lead dyes". Followed by, a series of electrochemical and photo-physical parameters were computed for designed dyes to check the required variables for electron flow of dye-sensitized solar cells. The combined computational techniques yielded seven promising lead dyes each for all three chemical classes considered. Significant (130, 183, and 46%) increment in predicted %power conversion efficiency was observed comparing with the existing dye with highest experimental %power conversion efficiency value for tetrahydroquinoline, N,N'-dialkylaniline and indoline, respectively maintaining required electrochemical parameters.

Functionalized nanostructures for enhanced photocatalytic performance under solar light.

PubMed

Guo, Liejin; Jing, Dengwei; Liu, Maochang; Chen, Yubin; Shen, Shaohua; Shi, Jinwen; Zhang, Kai

2014-01-01

Photocatalytic hydrogen production from water has been considered to be one of the most promising solar-to-hydrogen conversion technologies. In the last decade, various functionalized nanostructures were designed to address the primary requirements for an efficient photocatalytic generation of hydrogen by using solar energy: visible-light activity, chemical stability, appropriate band-edge characteristics, and potential for low-cost fabrication. Our aim is to present a short review of our recent attempts that center on the above requirements. We begin with a brief introduction of photocatalysts coupling two or more semiconductors, followed by a further discussion of the heterostructures with improved matching of both band structures and crystal lattices. We then elaborate on the heterostructure design of the targeted materials from macroscopic regulation of compositions and phases, to the more precise control at the nanoscale, i.e., materials with the same compositions but different phases with certain band alignment. We conclude this review with perspectives on nanostructure design that might direct future research of this technology.

Light harvesting over a wide range of wavelength using natural dyes of gardenia and cochineal for dye-sensitized solar cells.

PubMed

Park, Kyung-Hee; Kim, Tae-Young; Han, Shin; Ko, Hyun-Seok; Lee, Suk-Ho; Song, Yong-Min; Kim, Jung-Hun; Lee, Jae-Wook

2014-07-15

Two natural dyes extracted from gardenia yellow (Gardenia jasminoides) and cochineal (Dactylopius coccus) were used as sensitizers in the assembly of dye-sensitized solar cells (DSSCs) to harvest light over a wide range of wavelengths. The adsorption characteristics, electrochemical properties and photovoltaic efficiencies of the natural DSSCs were investigated. The adsorption kinetics data of the dyes were obtained in a small adsorption chamber and fitted with a pseudo-second-order model. The photovoltaic performance of a photo-electrode adsorbed with single-dye (gardenia or cochineal) or the mixture or successive adsorption of the two dyes, was evaluated from current-voltage measurements. The energy conversion efficiency of the TiO2 electrode with the successive adsorption of cochineal and gardenia dyes was 0.48%, which was enhanced compared to single-dye adsorption. Overall, a double layer of the two natural dyes as sensitizers was successfully formulated on the nanoporous TiO2 surface based on the differences in their adsorption affinities of gardenia and cochineal. Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of Donor Strength and Bulk on Thieno[3,4-b]-pyrazine-Based Panchromatic Dyes in Dye-Sensitized Solar Cells.

PubMed

Liyanage, Nalaka P; Cheema, Hammad; Baumann, Alexandra R; Zylstra, Alexa R; Delcamp, Jared H

2017-06-22

Near-infrared-absorbing organic dyes are critically needed in dye-sensitized solar cells (DSCs). Thieno[3,4-b]pyrazine (TPz) based dyes can access the NIR spectral region and show power conversion efficiencies (PCEs) of up to 8.1 % with sunlight being converted at wavelengths up to 800 nm for 17.6 mA cm -2 of photocurrent in a co-sensitized DSC device. Precisely controlling dye excited-state energies is critical for good performances in NIR DSCs. Strategies to control TPz dye energetics with stronger donor groups and TPz substituent choice are evaluated here. Additionally, donor size influence versus dye loading on TPz dyes is analyzed with respect to the TiO 2 surface protection designed to prevent recombination of electrons in TiO 2 with the redox shuttle. Importantly, the dyes evaluated were demonstrated to work well with low Li + concentration electrolytes, with iodine and cobalt redox shuttle systems, and efficiently as part of co-sensitized devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Critical Evaluation of the Influence of the Dark Exchange Current on the Performance of Dye-Sensitized Solar Cells

PubMed Central

García-Rodríguez, Rodrigo; Villanueva-Cab, Julio; Anta, Juan A.; Oskam, Gerko

2016-01-01

The influence of the thickness of the nanostructured, mesoporous TiO2 film on several parameters determining the performance of a dye-sensitized solar cell is investigated both experimentally and theoretically. We pay special attention to the effect of the exchange current density in the dark, and we compare the values obtained by steady state measurements with values extracted from small perturbation techniques. We also evaluate the influence of exchange current density, the solar cell ideality factor, and the effective absorption coefficient of the cell on the optimal film thickness. The results show that the exchange current density in the dark is proportional to the TiO2 film thickness, however, the effective absorption coefficient is the parameter that ultimately defines the ideal thickness. We illustrate the importance of the exchange current density in the dark on the determination of the current–voltage characteristics and we show how an important improvement of the cell performance can be achieved by decreasing values of the total series resistance and the exchange current density in the dark. PMID:28787833

Fabrication of dye-sensitized solar cell (DSSC) using annato seeds (Bixa orellana Linn)

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

Haryanto, Ditia Allindira; Landuma, Suarni; Purwanto, Agus

2014-02-24

The Fabrication of dye sensitized solar cell (DSSC) using Annato seeds has been conducted in this study. Annato seeds (Bixa orellana Linn) used as a sensitizer for dye sensitized solar cell. The experimental parameter was concentration of natural dye. Annato seeds was extracted using etanol solution and the concentration was controlled by varying mass of Annato seeds. A semiconductor TiO{sub 2} was prepared by a screen printing method for coating glass use paste of TiO{sub 2}. Construction DSSC used layered systems (sandwich) consists of working electrode (TiO{sub 2} semiconductor-dye) and counter electrode (platina). Both are placed on conductive glass andmore » electrolytes that occur electrons cycle. The characterization of thin layer of TiO{sub 2} was conducted using SEM (Scanning Electron Microscpy) analysis showed the surface morphology of TiO{sub 2} thin layer and the cross section of a thin layer of TiO{sub 2} with a thickness of 15–19 μm. Characterization of natural dye extract was determined using UV-Vis spectrometry analysis shows the wavelength range annato seeds is 328–515 nm, and the voltage (V{sub oc}) and electric current (I{sub sc}) resulted in keithley test for 30 gram, 40 gram, and 50 gram were 0,4000 V; 0,4251 V; 0,4502 V and 0,000074 A; 0,000458 A; 0,000857 A, respectively. The efficiencies of the fabricated solar cells using annato seeds as senstizer for each varying mass are 0,00799%, 0,01237%, and 0,05696%.« less

Efficient dye regeneration at low driving force achieved in triphenylamine dye LEG4 and TEMPO redox mediator based dye-sensitized solar cells.

PubMed

Yang, Wenxing; Vlachopoulos, Nick; Hao, Yan; Hagfeldt, Anders; Boschloo, Gerrit

2015-06-28

Minimizing the driving force required for the regeneration of oxidized dyes using redox mediators in an electrolyte is essential to further improve the open-circuit voltage and efficiency of dye-sensitized solar cells (DSSCs). Appropriate combinations of redox mediators and dye molecules should be explored to achieve this goal. Herein, we present a triphenylamine dye, LEG4, in combination with a TEMPO-based electrolyte in acetonitrile (E(0) = 0.89 V vs. NHE), reaching an efficiency of up to 5.4% under one sun illumination and 40% performance improvement compared to the previously and widely used indoline dye D149. The origin of this improvement was found to be the increased dye regeneration efficiency of LEG4 using the TEMPO redox mediator, which regenerated more than 80% of the oxidized dye with a driving force of only ∼0.2 eV. Detailed mechanistic studies further revealed that in addition to electron recombination to oxidized dyes, recombination of electrons from the conducting substrate and the mesoporous TiO2 film to the TEMPO(+) redox species in the electrolyte accounts for the reduced short circuit current, compared to the state-of-the-art cobalt tris(bipyridine) electrolyte system. The diffusion length of the TEMPO-electrolyte based DSSCs was determined to be ∼0.5 μm, which is smaller than the ∼2.8 μm found for cobalt-electrolyte based DSSCs. These results show the advantages of using LEG4 as a sensitizer, compared to previously record indoline dyes, in combination with a TEMPO-based electrolyte. The low driving force for efficient dye regeneration presented by these results shows the potential to further improve the power conversion efficiency (PCE) of DSSCs by utilizing redox couples and dyes with a minimal need of driving force for high regeneration yields.

Effect of polymer electrolyte on the performance of natural dye sensitized solar cells

NASA Astrophysics Data System (ADS)

Adel, R.; Abdallah, T.; Moustafa, Y. M.; Al-sabagh, A. M.; Talaat, H.

2015-10-01

Polymer electrolyte based on polyacrylonitrile (PAN), Ethylene Carbonate (EC) and Acetonitrile (ACN) mixed with Potassium Iodide and Iodine in liquid and thin film forms were employed in natural dye sensitized solar cells (NDSSCs). Three natural dyes; black berry, hibiscus and rose are used as the sensitizing dye. The NDSSCs used, follow the configuration: FTO/TiO2/Natural Dye/Electrolyte/ Carbon/FTO. The liquid form polymer electrolyte with black berry natural dye gives an increase of 111% in short circuit photocurrent density (Jsc), 17.5% to open circuit voltage (Voc), fill factor of 0.57 ± 0.05 and three times increase in the conversion efficiency of 0.242 ± 0.012% compared to the iodine electrolyte.

Enhanced Photovoltaic Performances of Dye-Sensitized Solar Cells by Co-Sensitization of Benzothiadiazole and Squaraine-Based Dyes.

PubMed

Islam, Ashraful; Akhtaruzzaman, Md; Chowdhury, Towhid H; Qin, Chuanjiang; Han, Liyuan; Bedja, Idriss M; Stalder, Romain; Schanze, Kirk S; Reynolds, John R

2016-02-01

Dye-sensitized solar cells (DSSCs) based on a donor-acceptor-donor oligothienylene dye containing benzothiadiazole (T4BTD-A) were cosensitized with dyes containing cis-configured squaraine rings (HSQ3 and HSQ4). The cosensitized dyes showed incident monochromatic photon-to-current conversion efficiency (IPCE) greater than 70% in the 300-850 nm wavelength region. The individual overall conversion efficiencies of the sensitizers T4BTD-A, HSQ3, and HSQ4 were 6.4%, 4.8%, and 5.8%, respectively. Improved power conversion efficiencies of 7.0% and 7.7% were observed when T4BTD-A was cosensitized with HSQ3 and HSQ4, respectively, thanks to a significant increase in current density (JSC) for the cosensitized DSSCs. Intensity-modulated photovoltage spectroscopy results showed a longer lifetime for cosensitized T4BTD-A+HSQ3 and T4BTD-A+HSQ4 compared to that of HSQ3 and HSQ4, respectively.

The chemical bonds effect of anthocyanin and chlorophyll dyes on TiO2 for dye-sensitized solar cell (DSSC)

NASA Astrophysics Data System (ADS)

Ahliha, A. H.; Nurosyid, F.; Supriyanto, A.; Kusumaningsih, T.

2017-11-01

Anthocyanin and chlorophyll dyes have been blended as the photosensitizer of Dye-Sensitized Solar Cell (DSSC). The results study showed the effect of chemical bond dyes on TiO2 and the efficiency of DSSC. Ratio blend of the anthocyanin and chlorophyll dyes are 1:1. The absorbance of dyes and TiO2 were characterized using UV-Vis Spectrophotometer. The chemical bonds contained in TiO2-dyes were characterized using FT-IR spectrophotometer. The efficiency of DSSC was calculated using I-V meter. The absorption spectra of chlorophyll: anthocyanin blend dye solutions and TiO2 films can increase after the dye adsorption. Absorbance characterization of anthocyanin and chlorophyll dye blend solutions showed three peaks at the wavelength of 412 nm; 535.5 nm; and 656.5 nm. Absorbance characterization of spinach before being blend with anthocyanin dyes solutions showed two peaks at the wavelength of 431 nm and 665.5 nm. The absorption spectra of TiO2 films can increase after the dyes adsorption at the wavelength of 400 nm. FT-IR spectra of TiO2 founded the functional groups C-Br, C=C, and O-H. The functional groups founded in anthocyanin: chlorophyll dye blended on the surface of TiO2 are C-Br, C-O, O-H, C-H, C=C, C=O, and O-H. The result showed that the greatest efficiency of 0.0544% at dye red cabbage-spinach. Adsorption blends of anthocyanin and chlorophyll dyes on the surface of TiO2 can be used as the photosensitizer for DSSC.

Effect of composition of chlorophyll and ruthenium dyes mixture (hybrid) on the dye-sensitized solar cell performance

NASA Astrophysics Data System (ADS)

Pratiwi, D. D.; Nurosyid, F.; Kusumandari; Supriyanto, A.; Suryana, R.

2018-03-01

The fabrication of dye-sensitized solar cell (DSSC) has been conducted by varying the composition of natural dye from moss chlorophyll (Bryophyte) and synthesis dye from ruthenium complex N719. The sandwich structure of DSSC consists of the working electrode using TiO2, dye, electrolyte, and counter electrode using carbon. The composition of chlorophyll and synthesis dyes mixture were 100% and 0%, 80% and 20%, 60% and 40%, 40% and 60%, and 20% and 80%. The UV-Vis absorption spectra of moss chlorophyll showed the first peak in the wavelength range of 450-500 nm and the second peak at wavelength of 650-700 nm. The peak value of absorbance at wavelengths of 450-500 nm was 6.1004 and at wavelengths of 650-700 nm was 3.5835. The IPCE characteristic curves showed the absorption peak of photon for DSSCs occurred at wavelength of 550-650 nm. It considered that photon in this wavelength can contribute dominantly to produce the optimum electrons. The I-V characteristics of DSSCs with composition of chlorophyll and synthesis dyes mixture of 100% and 0%, 80% and 20%, 60% and 40%, 40% and 60%, and 20% and 80% resulted the efficiency of 0.0022; 0.0194; 0.0239; 0.0342; and 0.0414, respectively. It suggested that the addition of a little composition of the ruthenium complex dye into moss chlorophyll dye can increase the efficiency significantly.

Modulation of π-spacer of carbazole-carbazole based organic dyes toward high efficient dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Chitpakdee, Chirawat; Jungsuttiwong, Siriporn; Sudyoadsuk, Taweesak; Promarak, Vinich; Kungwan, Nawee; Namuangruk, Supawadee

2017-03-01

The effects of type and position of π-linker in carbazole-carbazole based dyes on their performance in dye-sensitized solar cells (DSSCs) were investigated by DFT and TDDFT methods. The calculated electronic energy level, electron density composition, charge injection and charge recombination properties were compared with those of the high performance CCT3A dye synthesized recently. It is found that that mixing a benzothiadizole (B) unit with two thiophene (T) units in the π-spacer can greatly shift absorption wavelength to near infrared region and enhance the light harvesting efficiency (LHE) resulting in increasing of short-circuit current density (Jsc), whereas a thienothiophene unit does not affect those properties. However, a B should be not directly connected to the anchoring group of the dye because it brings electrolyte to the TiO2 surface which may increase charge recombination rate and consequently decrease open circuit voltage (Voc). This work shows how type and position of the π-linker affect the performance of DSSCs, and how to modulate those properties. We predicted that the designed dye derived from insertion of the B unit in between the two T units would have higher performance than CCT3A dye. The insight understanding from this study is useful for further design of higher performance dyes by molecular engineering.

Broadband enhancement of dielectric light trapping nanostructure used in ultra-thin solar cells

NASA Astrophysics Data System (ADS)

Yang, Dong; Xu, Zhaopeng; Bian, Fei; Wang, Haiyan; Wang, Jiazhuang; Sun, Lu

2018-03-01

A dielectric fishnet nanostructure is designed to increase the light trapping capability of ultra-thin solar cells. The complex performance of ultra-thin cells such as the optical response and electrical response are fully quantified in simulation through a complete optoelectronic investigation. The results show that the optimized light trapping nanostructure can enhances the electromagnetic resonance in active layer then lead to extraordinary enhancement of both absorption and light-conversion capabilities in the solar cell. The short-circuit current density increases by 49.46% from 9.40 mA/cm2 to 14.05 mA/cm2 and light-conversion efficiency increases by 51.84% from 9.51% to 14.44% compared to the benchmark, a solar cell with an ITO-GaAs-Ag structure.

Nanostructured GaAs solar cells via metal-assisted chemical etching of emitter layers.

PubMed

Song, Yunwon; Choi, Keorock; Jun, Dong-Hwan; Oh, Jungwoo

2017-10-02

GaAs solar cells with nanostructured emitter layers were fabricated via metal-assisted chemical etching. Au nanoparticles produced via thermal treatment of Au thin films were used as etch catalysts to texture an emitter surface with nanohole structures. Epi-wafers with emitter layers 0.5, 1.0, and 1.5 um in thickness were directly textured and a window layer removal process was performed before metal catalyst deposition. A nanohole-textured emitter layer provides effective light trapping capabilities, reducing the surface reflection of a textured solar cell by 11.0%. However, because the nanostructures have high surface area to volume ratios and large numbers of defects, various photovoltaic properties were diminished by high recombination losses. Thus, we have studied the application of nanohole structures to GaAs emitter solar cells and investigated the cells' antireflection and photovoltaic properties as a function of the nanohole structure and emitter thickness. Due to decreased surface reflection and improved shunt resistance, the solar cell efficiency increased from 4.25% for non-textured solar cells to 7.15% for solar cells textured for 5 min.

The influence of local electric fields on photoinduced absorption in dye-sensitized solar cells.

PubMed

Cappel, Ute B; Feldt, Sandra M; Schöneboom, Jan; Hagfeldt, Anders; Boschloo, Gerrit

2010-07-07

The dye-sensitized solar cell (DSC) challenges conventional photovoltaics with its potential for low-cost production and its flexibility in terms of color and design. Transient absorption spectroscopy is widely used to unravel the working mechanism of DSCs. A surprising, unexplained feature observed in these studies is an apparent bleach of the ground-state absorption of the dye, under conditions where the dye is in the ground state. Here, we demonstrate that this feature can be attributed to a change of the local electric field affecting the absorption spectrum of the dye, an effect related to the Stark effect first reported in 1913. We present a method for measuring the effect of an externally applied electric field on the absorption of dye monolayers adsorbed on flat TiO(2) substrates. The measured signal has the shape of the first derivative of the absorption spectra of the dyes and reverses sign along with the reversion of the direction of the change in dipole moment upon excitation relative to the TiO(2) surface. A very similar signal is observed in photoinduced absorption spectra of dye-sensitized TiO(2) electrodes under solar cell conditions, demonstrating that the electric field across the dye molecules changes upon illumination. This result has important implications for the analysis of transient absorption spectra of DSCs and other molecular optoelectronic devices and challenges the interpretation of many previously published results.

Near infrared harvesting dye-sensitized solar cells enabled by rare-earth upconversion materials.

PubMed

Li, Deyang; Ågren, Hans; Chen, Guanying

2018-02-01

Dye-sensitized solar cells (DSSCs) have been deemed as promising alternatives to silicon solar cells for the conversion of clean sunlight energy into electricity. A major limitation to their conversion efficiency is their inability to utilize light in the infrared (IR) spectral range, which constitutes almost half the energy of the sun's radiation. This fact has elicited motivations and endeavors to extend the response wavelength of DSSCs to the IR range. Photon upconversion through rare-earth ions constitutes one of the most promising approaches toward the goal of converting near-IR (NIR) or IR light into visible or ultraviolet light, where DSSCs typically have high sensitivity. In the present review, we summarize recent progress based on the utilization of various upconversion materials and device structures to improve the performance of dye-sensitized solar cells.

Theoretical Study of Ultrafast Electron Injection into a Dye/TiO2 System in Dye-Sensitized Solar Cells

NASA Astrophysics Data System (ADS)

Lin, Chundan; Xia, Qide; Li, Kuan; Li, Juan; Yang, Zhenqing

2018-06-01

The ultrafast injection of excited electrons in dye/TiO2 system plays a critical role, which determines the device's efficiency in large part. In this work, we studied the geometrical structures and electronic properties of a dye/TiO2 composite system for dye-sensitized solar cells (DSSCs) by using density functional theory, and we analyzed the mechanism of ultrafast electron injection with emphasis on the power conversion efficiency. The results show that the dye SPL103/TiO2 (101) surface is more stable than dye SPL101. The electron injection driving force of SPL103/TiO2 (101) is 3.55 times that of SPL101, indicating that SPL103/TiO2 (101) has a strong ability to transfer electrons. SPL103 and SPL101/TiO2 (101) both have fast electron transfer processes, and especially the electron injection time of SPL103/TiO2 (101) is only 1.875 fs. The results of this work are expected to provide a new understanding of the mechanism of electron injection in dyes/TiO2 systems for use in highly effective DSSCs.

Trade-off between Photon Management Efficacy and Material Quality in Thin-Film Solar Cells on Nanostructured Substrates of High Aspect Ratio Structures

DOE PAGES

Chin, Alan; Keshavarz, Majid; Wang, Qi

2018-04-13

Although texturing of the transparent electrode of thin-film solar cells has long been used to enhance light absorption via light trapping, such texturing has involved low aspect ratio features. With the recent development of nanotechnology, nanostructured substrates enable improved light trapping and enhanced optical absorption via resonances, a process known as photon management, in thin-film solar cells. Despite the progress made in the development of photon management in thin-film solar cells using nanostructures substrates, the structural integrity of the thin-film solar cells deposited onto such nanostructured substrates is rarely considered. Here, we report the observation of the reduction in themore » open circuit voltage of amorphous silicon solar cells deposited onto a nanostructured substrate with increasing areal number density of high aspect ratio structures. For a nanostructured substrate with the areal number density of such nanostructures increasing in correlation with the distance from one edge of the substrate, a correlation between the open circuit voltage reduction and the increase of the areal number density of high aspect ratio nanostructures of the front electrode of the small-size amorphous silicon solar cells deposited onto different regions of the substrate with graded nanostructure density indicates the effect of the surface morphology on the material quality, i.e., a trade-off between photon management efficacy and material quality. Lastly, this observed trade-off highlights the importance of optimizing the morphology of the nanostructured substrate to ensure conformal deposition of the thin-film solar cell.« less

Trade-off between Photon Management Efficacy and Material Quality in Thin-Film Solar Cells on Nanostructured Substrates of High Aspect Ratio Structures

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

Chin, Alan; Keshavarz, Majid; Wang, Qi

Although texturing of the transparent electrode of thin-film solar cells has long been used to enhance light absorption via light trapping, such texturing has involved low aspect ratio features. With the recent development of nanotechnology, nanostructured substrates enable improved light trapping and enhanced optical absorption via resonances, a process known as photon management, in thin-film solar cells. Despite the progress made in the development of photon management in thin-film solar cells using nanostructures substrates, the structural integrity of the thin-film solar cells deposited onto such nanostructured substrates is rarely considered. Here, we report the observation of the reduction in themore » open circuit voltage of amorphous silicon solar cells deposited onto a nanostructured substrate with increasing areal number density of high aspect ratio structures. For a nanostructured substrate with the areal number density of such nanostructures increasing in correlation with the distance from one edge of the substrate, a correlation between the open circuit voltage reduction and the increase of the areal number density of high aspect ratio nanostructures of the front electrode of the small-size amorphous silicon solar cells deposited onto different regions of the substrate with graded nanostructure density indicates the effect of the surface morphology on the material quality, i.e., a trade-off between photon management efficacy and material quality. Lastly, this observed trade-off highlights the importance of optimizing the morphology of the nanostructured substrate to ensure conformal deposition of the thin-film solar cell.« less

Insights into the Mechanism of a Covalently Linked Organic Dye-Cobaloxime Catalyst System for Dye-Sensitized Solar Fuel Devices.

PubMed

Pati, Palas Baran; Zhang, Lei; Philippe, Bertrand; Fernández-Terán, Ricardo; Ahmadi, Sareh; Tian, Lei; Rensmo, Håkan; Hammarström, Leif; Tian, Haining

2017-06-09

A covalently linked organic dye-cobaloxime catalyst system based on mesoporous NiO is synthesized by a facile click reaction for mechanistic studies and application in a dye-sensitized solar fuel device. The system is systematically investigated by photoelectrochemical measurements, density functional theory, time-resolved fluorescence, transient absorption spectroscopy, and photoelectron spectroscopy. The results show that irradiation of the dye-catalyst on NiO leads to ultrafast hole injection into NiO from the excited dye, followed by a fast electron transfer process to reduce the catalyst. Moreover, the dye adopts different structures with different excited state energies, and excitation energy transfer occurs between neighboring molecules on the semiconductor surface. The photoelectrochemical experiments also show hydrogen production by this system. The axial chloride ligands of the catalyst are released during photocatalysis to create the active sites for proton reduction. A working mechanism of the dye-catalyst system on the photocathode is proposed on the basis of this study. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Theoretical studies on effective metal-to-ligand charge transfer characteristics of novel ruthenium dyes for dye sensitized solar cells.

PubMed

Wang, Huei-Tang; Taufany, Fadlilatul; Nachimuthu, Santhanamoorthi; Jiang, Jyh-Chiang

2014-05-01

The development of ruthenium dye-sensitizers with highly effective metal-to-ligand charge transfer (MLCT) characteristics and narrowed transition energy gaps are essential for the new generation of dye-sensitized solar cells. Here, we designed a novel anchoring ligand by inserting the cyanovinyl-branches inside the anchoring ligands of selected highly efficient dye-sensitizers and studied their intrinsic optical properties using theoretical methods. Our calculated results show that the designed ruthenium dyes provide good performances as sensitizers compared to the selected efficient dyes, because of their red-shift in the UV-visible absorption spectra with an increase in the absorption intensity, smaller energy gaps and thereby enhancing MLCT transitions. We found that, the designed anchoring ligand acts as an efficient "electron-acceptor" which boosts electron-transfer from a -NCS ligand to this ligand via a Ru-bridge, thus providing a way to lower the transition energy gap and enhance the MLCT transitions.

Hyperbranched quasi-1D TiO2 nanostructure for hybrid organic-inorganic solar cells.

PubMed

Ghadirzadeh, Ali; Passoni, Luca; Grancini, Giulia; Terraneo, Giancarlo; Li Bassi, Andrea; Petrozza, Annamaria; Di Fonzo, Fabio

2015-04-15

The performance of hybrid solar cells is strongly affected by the device morphology. In this work, we demonstrate a poly(3-hexylthiophene-2,5-diyl)/TiO2 hybrid solar cell where the TiO2 photoanode comprises an array of tree-like hyperbranched quasi-1D nanostructures self-assembled from the gas phase. This advanced architecture enables us to increase the power conversion efficiency to over 1%, doubling the efficiency with respect to state of the art devices employing standard mesoporous titania photoanodes. This improvement is attributed to several peculiar features of this array of nanostructures: high interfacial area; increased optical density thanks to the enhanced light scattering; and enhanced crystallization of poly(3-hexylthiophene-2,5-diyl) inside the quasi-1D nanostructure.

Efficiency enhancement using voltage biasing for ferroelectric polarization in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Kim, Sangmo; Song, Myoung Geun; Bark, Chung Wung

2018-01-01

Dye-sensitized solar cells (DSSCs) are one of the most promising third generation solar cells that have been extensively researched over the past decade as alternative to silicon-based solar cells, due to their low production cost and high energy-conversion efficiency. In general, a DSSC consists of a transparent electrode, a counter electrode, and an electrolyte such as dye. To achieve high power-conversion efficiency in cells, many research groups have focused their efforts on developing efficient dyes for liquid electrolytes. In this work, we report on the photovoltaic properties of DSSCs fabricated using a mixture of TiO2 with nanosized Fe-doped bismuth lanthanum titanate (nFe-BLT) powder). Firstly, nFe-BLT powders were prepared using a high-energy ball milling process and then, TiO2 and nFe-BLT powders were stoichiometrically blended. Direct current (DC) bias of 20 MV/m was applied to lab-made DSSCs. With the optimal concentration of nFe-BLT doped in the electrode, their light-to-electricity conversion efficiency could be improved by ∼64% compared with DSSCs where no DC bias was applied.

Potential of roselle and blue pea in the dye-sensitized solar cell

NASA Astrophysics Data System (ADS)

Dayang, S.; Irwanto, M.; Gomesh, N.; Ismail, B.

2017-09-01

This paper discovers the use of natural dyes from Roselle flower and Blue Pea flower which act as a sensitizer in DSSC and in addition has a potential in absorbing visible light spectrum. The dyes were extracted using distilled water (DI) and ethanol (E) extract solvent in an ultrasonic cleaner for 30 minutes with a frequency of 37 Hz by using `degas' mode at the temperature of 30°C. Absorption spectra of roselle dye and blue pea dye with different extract solvent were tested using Evolution 201 UV-Vis Spectrophotometer. It was found that Roselle dye absorbs at a range of 400 nm - 620 nm and Blue Pea absorbs at the range of wavelength 500 nm - 680 nm. Fourier-Transform Infrared (FTIR) was used to identify the functional active group in extract dye. The concept of Dye-Sensitized Solar Cell (DSSC) similar to photosynthesis process has attracted much attention since it demonstrates a great potential due to the use of low-cost materials and environmentally friendly sources of technology.

Photocurrent enhanced by singlet fission in a dye-sensitized solar cell.

PubMed

Schrauben, Joel N; Zhao, Yixin; Mercado, Candy; Dron, Paul I; Ryerson, Joseph L; Michl, Josef; Zhu, Kai; Johnson, Justin C

2015-02-04

Investigations of singlet fission have accelerated recently because of its potential utility in solar photoconversion, although only a few reports definitively identify the role of singlet fission in a complete solar cell. Evidence of the influence of singlet fission in a dye-sensitized solar cell using 1,3-diphenylisobenzofuran (DPIBF, 1) as the sensitizer is reported here. Self-assembly of the blue-absorbing 1 with co-adsorbed oxidation products on mesoporous TiO2 yields a cell with a peak internal quantum efficiency of ∼70% and a power conversion efficiency of ∼1.1%. Introducing a ZrO2 spacer layer of thickness varying from 2 to 20 Å modulates the short-circuit photocurrent such that it is initially reduced as thickness increases but 1 with 10-15 Å of added ZrO2. This rise can be explained as being due to a reduced rate of injection of electrons from the S1 state of 1 such that singlet fission, known to occur with a 30 ps time constant in polycrystalline films, has the opportunity to proceed efficiently and produce two T1 states per absorbed photon that can subsequently inject electrons into TiO2. Transient spectroscopy and kinetic simulations confirm this novel mode of dye-sensitized solar cell operation and its potential utility for enhanced solar photoconversion.

Facile synthesis of Zn1-xCoxO/ZnO core/shell nanostructures and their application to dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Manthina, Venkata; Agrios, Alexander G.

2017-04-01

Heterostructures consisting of Co-doped ZnO nanorod cores encased in an undoped ZnO shell were successfully synthesized to serve as photoanodes for dye-sensitized solar cells (DSSCs) by a two-step chemical bath deposition (CBD) technique. This yields a highly favorable structure in which electrons injected from the dye into the ZnO then step down in energy into the Co-doped core, where the electron is transported to the collector while the ZnO shell acts as a barrier to recombination with the electrolyte. Incorporation of the core/shell structures into DSSCs resulted in large improvements in photocurrent and photovoltage in comparison to pure ZnO nanorod-based DSSCs. SEM and XRD characterization indicate incorporation of the Co2+ into the ZnO matrix, without separation of the Co into other phases, providing no energy barriers. In addition, the ability of these heterostructures to reduce recombination rates in redox couples with fast recombination rates was probed by comparing DSSC device performance in both iodide/triiodide-based and ferrocene/ferrocenium-based electrolytes.

High resolution TEM and 3D imaging of polymer-based and dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Suh, Youngjoon

Since 1950s, solar energy has been the most attractive energy source as an alternative to fossil fuels including oil and natural gas. However, these types of solar cells have high raw material and manufacturing costs. So, alternative solar cells using low cost materials and manufacturing processes have been actively studied for more than 10 years. The power conversion efficiency of some of the alternative solar cells has been recently improved so much as to be used for real life applications in the near future. However, their relatively short lifetime still remains as a bottleneck in their commercialized use. In this dissertation, we studied cross sections of three types of solar cells using TEM micrographs and TEM related analysis methods; selected area diffraction, energy dispersive spectroscopy, electron tomography, and nanobeam diffraction. A thin Ag layer used for a top metal electrode in an inverted polymer solar cell was broken down into particles. Absorption of water by the PEDOT:PSS layer followed by corrosion of the Ag layer was thought to be the main cause of this phenomenon. The structure and materials of the photoactive layer in hybrid polymer solar cells have an important influence on the performance of the solar cell devices. Three kinds of efforts were made to improve the electrical characteristics of the devices; removal of a dark TiO2 layer at the polymer/TiO2 interface, using bulk heterojunction structures, and coating a fullerene interlayer on the inorganic nanostructure. An optimum concentration of carbon nanotubes (CNTs) combined with Ru could increase the interface area of CNTs, and improve the performances of dye sensitized solar cells. In order to develop plastic solar cell, two different methods of mixing TiO2 particles with either nanoglues or PMMA were tried. Cross-sectional TEM microstructures were examined to come up with optimum processing parameters such as the sintering temperature and the amount of PMMA added into the structure

Time-dependent efficiency measurements of polymer solar cells with dye additives: unexpected initial increase of efficiency

NASA Astrophysics Data System (ADS)

Bandaccari, Kyle J.; Chesmore, Grace E.; Bugaj, Mitchel; Valverde, Parisa Tajalli-Tehrani; Barber, Richard P.; McNelis, Brian J.

2018-04-01

We report the effects of the addition of two azo-dye additives on the time-dependent efficiency of polymer solar cells. Although the maximum efficiencies of devices containing different amounts of dye do not vary greatly over the selected concentration range, the time dependence results reveal a surprising initial increase in efficiency in some samples. We observe this effect to be correlated with a leakage current, although a specific mechanism is not yet identified. We also present the measured lifetimes of these solar cells, and find that variations in dye concentrations produce a small effect at most. Characterization of the bulk heterojunction layer (active layer) morphology using atomic-force microscope (AFM) imaging reveals reordering patterns which suggest that the primary effects of the dyes arise via structural, not absorptive, characteristics.

Fabrication and characterization of nanowalls CdS/dye sensitized solar cells

NASA Astrophysics Data System (ADS)

Abdulelah, Haider; Ali, Basil; Mahdi, M. A.; Hassan, J. J.; Al-Taay, H. F.; Jennings, P.

2017-06-01

A microwave assisted chemical bath deposition (MA-CBD) was adopted to fabricate nanowalls CdS nanocrystalline thin film. Nanomaterials (such as nanowalls structure) have attracted significant attention due to their fascinating properties and unique applications, especially in optoelectronic nanodevices. Here we describe the fabrication of dye sensitized solar cells (DSSCs) based nanowalls cadmium sulfide (CdS) nanocrystalline thin films. The surface morphology, crystalline structure, and optical properties of the prepared nanocrystalline thin films are investigated. Rhodamine B, Malachite green, Eosin methylene blue, and Cresyl violet perchlorate dyes are used to fabricate the DSSCS devices. Current-voltage (I-V) characteristics show that the nanowall CdS/Eosin methylene blue device is the highest conversion efficiency of 0.89% under 100 mW/cm2. However, heat treatment of the fabricated solar cells causes significant enhancement in the output of all devices.

[1]Benzothieno[3,2-b]benzothiophene-Based Organic Dyes for Dye-Sensitized Solar Cells.

PubMed

Capodilupo, Agostina L; Fabiano, Eduardo; De Marco, Luisa; Ciccarella, Giuseppe; Gigli, Giuseppe; Martinelli, Carmela; Cardone, Antonio

2016-04-15

Three new metal-free organic dyes with the [1]benzothieno[3,2-b]benzothiophene (BTBT) π-bridge, having the structure donor-π-acceptor (D-π-A) and labeled as 19, 20 and 21, have been designed and synthesized for application in dye-sensitized solar cells (DSSC). Once the design of the π-acceptor block was fixed, containing the BTBT as the π-bridge and the cyanoacrylic group as the electron acceptor and anchoring unit, we selected three donor units with different electron-donor capacity, in order to assemble new chromophores with high molar extinction coefficients (ε), whose absorption features well reflect the good performance of the final DSSC devices. Starting with the 19 dye, which shows a molar extinction coefficient ε of over 14,000 M(-1) cm(-1) and takes into account the absorption maximun at the longer wavelength, the substitution of the BFT donor unit with the BFA yields a great enhancement of absorptivity (molar extinction coefficient ε > 42,000 M(-1) cm(-1)), until reaching the higher value (ε > 69,000 M(-1) cm(-1)) with the BFPhz donor unit. The good general photovoltaic performances obtained with the three dyes highlight the suitable properties of electron-transport of the BTBT as the π-bridge in organic chromophore for DSSC, making this very cheap and easy to synthesize molecule particularly attractive for efficient and low-cost photovoltaic devices.

Cosensitization of Structurally Simple Porphyrin and Anthracene-Based Dye for Dye-Sensitized Solar Cells.

PubMed

Reddy, Kamani Sudhir K; Chen, Yen-Chiao; Wu, Chih-Chung; Hsu, Chia-Wei; Chang, Ya-Ching; Chen, Chih-Ming; Yeh, Chen-Yu

2018-01-24

Since their introduction, dye-sensitized solar cells (DSCs) have achieved huge success at a laboratory level. Recently, research is concentrated to visualize large DSC modules at the commercial platform. In that aspect, we have tested structurally simple porphyrin-based dye SK6 and anthracene-based dye CW10 for DSCs application under simulated 1 sun (AM 1.5G) and indoor light sources. These two dyes can be easily synthesized and yet are efficient with cell performances of ca. 5.42% and ca. 5.75% (without coadsorbent/additive) for SK6 and CW10, respectively, under AM 1.5G illumination. The power conversion efficiency (PCE) of SK6 reported in this work is the highest ever reported; this is achieved by optimizing the adsorption of SK6 on TiO 2 photoanode using the most suitable solvent and immersion period. Cosensitization of SK6 with CW10 on TiO 2 surface has boosted cell performance further and achieved PCE of ca. 6.31% under AM 1.5G illumination. Charge-transfer properties of individual and cosensitized devices at TiO 2 /dye/electrolyte interface were examined via electrochemical impedance spectroscopy. To understand the cell performances under ambient light conditions, we soaked individual and cosensitized devices under T5 and light-emitting diode light sources in the range of 300-6000 lx. The PCE of ca. 22.91% under T5 light (6000 lx) with J SC = 0.883 mA cm -2 , V OC = 0.646 V, and FF = 0.749 was noted for the cosensitized device, which equals a power output of 426 μW cm -2 . These results reveal that DSCs made of structurally simple dyes performed efficiently under both 1 sun (AM 1.5G) and indoor light conditions, which is undoubtedly a significant achievement when it comes to a choice of commercial application.

Size Effects in Dye-Sensitized TiO2 Clusters

NASA Astrophysics Data System (ADS)

Marom, Noa; Körzdörfer, Thomas; Ren, Xinguo; Tkatchenko, Alexandre; Chelikowsky, James

2014-03-01

The development of solar cells is driven by the need for clean and sustainable energy. Organic and dye sensitized cells are considered as promising technologies, particularly for large area, low cost applications. However, the efficiency of such cells is still far from the theoretical limit. Ab initio simulations may be used for computer-aided design of new materials and nano-structures for more efficient solar cells. It is essential to obtain an accurate description of the electronic structure, including the fundamental gaps and energy level alignment at the interfaces in the device active region. This requires going beyond ground-state DFT to the GW approximation. A recently developed GW method [PRB 86, 041110R (2012)] is applied to dye-sensitized TiO2 clusters [PRB 84, 245115 (2011)]. The effect of cluster size on the energy level alignment at the dye-TiO2 interface is discussed. With the increase in the TiO2 cluster size its gap narrows. The gap of the molecule attached to the cluster subsequently narrows due to screening. As a result, the energy level alignment at the interface changes in an unexpected way [Marom, Körzdörfer, Ren, Tkatchenko, Chelikowsky, to be published].

Molecular lemmings: strategies to avoid when designing BODIPY ferrocene dyads for dye-sensitized solar cell applications.

PubMed

Hussein, B A; Huynh, J T; Prieto, P L; Barran, C P; Arnold, A E; Sarycheva, O V; Lough, A J; Koivisto, B D

2018-04-03

BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacenes) dyes possess intense absorption profiles that can be exploited in various light harvesting applications. However, redox stability and optimization of frontier molecular orbital energies in these dyes are critical for their successful incorporation into new solar cell materials. This article describes the synthesis and characterization of a family of β-substituted BODIPY-ferrocene dyads with push-pull architectures. Designed to stabilize the photo-oxidized BODIPY for dye-sensitized solar cell (DSSC) applications, some deleterious electron transfer behaviours emerged when the ferrocene unit was conjugated to electron deficient BODIPYs. These findings are discussed herein.

Eosin-Y sensitized core-shell TiO2-ZnO nano-structured photoanodes for dye-sensitized solar cell applications.

PubMed

Manikandan, V S; Palai, Akshaya K; Mohanty, Smita; Nayak, Sanjay K

2018-06-01

In the current investigation, TiO 2 and TiO 2 -ZnO (core-shell) spherical nanoparticles were synthesized by simple combined hydrolysis and refluxing method. A TiO 2 core nanomaterial on the shell material of ZnO was synthesized by utilizing variable ratios of ZnO. The structural characterization of TiO 2 -ZnO core/shell nanoparticles were done by XRD analysis. The spherical structured morphology of the TiO 2 -ZnO has been confirmed through field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) studies. The UV-visible spectra of TiO 2 -ZnO nanostructures were also compared with the pristine TiO 2 to investigate the shift of wavelength. The TiO 2 -ZnO core/shell nanoparticles at the interface efficiently collect the photogenarated electrons from ZnO and also ZnO act a barrier for reduced charge recombination of electrolyte and dye-nanoparticles interface. This combination improved the light absorption which induced the charge transfer ability and dye loading capacity of core-shell nanoparticles. An enhancement in the short circuit current (J sc ) from 1.67 mA/cm 2 to 2.1 mA/cm 2 has been observed for TiO 2 -ZnObased photoanode (with platinum free counter electrode), promises an improvement in the energy conversion efficiency by 57% in comparison with that of the DSSCs based on the pristine TiO 2 . Henceforth, TiO 2 -ZnO photoelectrode in ZnO will effectively act as barrier at the interface of TiO 2 -ZnO and TiO 2 , ensuring the potential for DSSC application. Copyright © 2018 Elsevier B.V. All rights reserved.

Theoretical Study of Effect of Introducing π-Conjugation on Efficiency of Dye-Sensitized Solar Cell.

PubMed

Lee, Geon Hyeong; Kim, Young Sik

2018-09-01

In this study, phenoxazine (PXZ)-based dye sensitizers with triphenylamine (TPA) as a dual-electron donor and thiophen and benzothiadiazole (BTD) or 4,7-diethynylbenzo[c][1,2,5]thiadiazole (DEBT) as an electron acceptor (dye1, dye2, and dye3) were designed and investigated. dye3 can significantly stabilize the lowest unoccupied molecular orbital (LUMO) energy level of an organic dye. We used density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations to better understand the factors responsible for the photovoltaic performance. The absorption spectrum of the dyes showed different forms because of the different energy levels of the molecular orbital (MO) of each dye and the intramolecular energy transfer (EnT). Among the three dyes, dye3 showed greater red-shift, broader absorption spectra, and higher molar extinction coefficient. These results indicate that adding a withdrawing unit and π-conjugation to a dye can result in good photovoltaic properties for dye-sensitized solar cells (DSSCs).

Array of titanium dioxide nanostructures for solar energy utilization

DOEpatents

Qiu, Xiaofeng; Parans Paranthaman, Mariappan; Chi, Miaofang; Ivanov, Ilia N; Zhang, Zhenyu

2014-12-30

An array of titanium dioxide nanostructures for solar energy utilization includes a plurality of nanotubes, each nanotube including an outer layer coaxial with an inner layer, where the inner layer comprises p-type titanium dioxide and the outer layer comprises n-type titanium dioxide. An interface between the inner layer and the outer layer defines a p-n junction.

A strategy to minimize the energy offset in carrier injection from excited dyes to inorganic semiconductors for efficient dye-sensitized solar energy conversion.

PubMed

Fujisawa, Jun-Ichi; Osawa, Ayumi; Hanaya, Minoru

2016-08-10

Photoinduced carrier injection from dyes to inorganic semiconductors is a crucial process in various dye-sensitized solar energy conversions such as photovoltaics and photocatalysis. It has been reported that an energy offset larger than 0.2-0.3 eV (threshold value) is required for efficient electron injection from excited dyes to metal-oxide semiconductors such as titanium dioxide (TiO2). Because the energy offset directly causes loss in the potential of injected electrons, it is a crucial issue to minimize the energy offset for efficient solar energy conversions. However, a fundamental understanding of the energy offset, especially the threshold value, has not been obtained yet. In this paper, we report the origin of the threshold value of the energy offset, solving the long-standing questions of why such a large energy offset is necessary for the electron injection and which factors govern the threshold value, and suggest a strategy to minimize the threshold value. The threshold value is determined by the sum of two reorganization energies in one-electron reduction of semiconductors and typically-used donor-acceptor (D-A) dyes. In fact, the estimated values (0.21-0.31 eV) for several D-A dyes are in good agreement with the threshold value, supporting our conclusion. In addition, our results reveal that the threshold value is possible to be reduced by enlarging the π-conjugated system of the acceptor moiety in dyes and enhancing its structural rigidity. Furthermore, we extend the analysis to hole injection from excited dyes to semiconductors. In this case, the threshold value is given by the sum of two reorganization energies in one-electron oxidation of semiconductors and D-A dyes.

Theoretical study of electronic transfer current rate at dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

AL-Agealy, Hadi J. M.; AlMaadhede, Taif Saad; Hassooni, Mohsin A.; Sadoon, Abbas K.; Ashweik, Ahmed M.; Mahdi, Hind Abdlmajeed; Ghadhban, Rawnaq Qays

2018-05-01

In this research, we present a theoretical study of electronic transfer kinetics rate in N719/TiO2 and N719/ZnO dye-sensitized solar cells (DSSC) systems using a simple model depending on the postulate of quantum mechanics theory. The evaluation of the electronic transition current rate in DSSC systems are function of many parameters such that; the reorientation transition energies ΛSe m D y e , the transition coupling parameter ℂT(0), potential exponential effect e-(E/C-EF ) kBT , unit cell volume VSem, and temperature T. Furthermore, the analysis of electronic transfer current rate in N719/TiO2 and N719/ZnO systems show that the rate upon dye-sensitization solar cell increases with increases of transition coupling parameter, decreasing potential that building at interface a results of different material in this devices and increasing with reorientation transition energy. On the other hand, we can find the electronic transfer behavior is dependent of the dye absorption spectrum and mainly depending on the reorientation of transition energy. The replacement of the solvents in both DSSC system caused increasing of current rates dramatically depending on polarity of solvent in subset devices. This change in current rate of electron transfer were attributed to much more available of recombination sites introduced by the solvents medium. The electronic transfer current dynamics are shown to occurs in N719/TiO2 system faster many time compare to ocuures at N719/ZnO system, this indicate that TiO2 a is a good and active material compare with ZnO to using in dye sensitized solar cell devices. In contrast, the large current rate in N719/TiO2 comparing to ZnO of N719/ZnO systems indicate that using TiO2 with N719 dye lead to increasing the efficiency of DSSC.

Control of interfacial charge-transfer interaction of dye and p-CuI in solid-state dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Moribe, Shinya; Kato, Naohiko; Higuchi, Kazuo; Mizumoto, Katsuyoshi; Toyoda, Tatsuo

2017-04-01

We systematically investigated the photovoltaic and absorption characteristics of solid-state dye-sensitized solar cells with CuI to elucidate the impact of the interaction between the dye and CuI. For the ruthenium complex N719, the incident photon-to-current conversion efficiency (IPCE) on the longer-wavelength side decreased owing to the change of the metal-to-ligand charge transfer (CT) of N719 due to the interaction between the thiocyanate groups of N719 and CuI. In contrast, when D149 — which included rhodanine groups — was used, the interaction with CuI and the resultant CT increased the IPCE. The results provide a new strategy for improving the photovoltaic performance by controlling the interfacial CT between the dye and CuI.

Role of Co-Sensitizers in Dye-Sensitized Solar Cells.

PubMed

Krishna, Narra Vamsi; Krishna, Jonnadula Venkata Suman; Mrinalini, Madoori; Prasanthkumar, Seelam; Giribabu, Lingamallu

2017-12-08

Co-sensitization is a popular route towards improved efficiency and stability of dye-sensitized solar cells (DSSCs). In this context, the power conversion efficiency (PCE) values of DSSCs incorporating Ru- and porphyrin-based dyes can be improved from 8-11 % to 11-14 % after the addition of additives, co-adsorbents, and co-sensitizers that reduce aggregation and charge recombination in the device. Among the three supporting material types, co-sensitizers play a major role to enhance the performance and stability of DSSCs, which is requried for commercialization. In this Minireview, we highlight the role co-sensitizers play in improving photovoltaic performance of devices containing Ru- and porphyrin-based sensitizers. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Flexible Dye-Sensitized Solar Cell Based on Vertical ZnO Nanowire Arrays

PubMed Central

2011-01-01

Flexible dye-sensitized solar cells are fabricated using vertically aligned ZnO nanowire arrays that are transferred onto ITO-coated poly(ethylene terephthalate) substrates using a simple peel-off process. The solar cells demonstrate an energy conversion efficiency of 0.44% with good bending tolerance. This technique paves a new route for building large-scale cost-effective flexible photovoltaic and optoelectronic devices. PMID:27502660

Highly efficient solar vapour generation via hierarchically nanostructured gels.

PubMed

Zhao, Fei; Zhou, Xingyi; Shi, Ye; Qian, Xin; Alexander, Megan; Zhao, Xinpeng; Mendez, Samantha; Yang, Ronggui; Qu, Liangti; Yu, Guihua

2018-04-02

Solar vapour generation is an efficient way of harvesting solar energy for the purification of polluted or saline water. However, water evaporation suffers from either inefficient utilization of solar energy or relies on complex and expensive light-concentration accessories. Here, we demonstrate a hierarchically nanostructured gel (HNG) based on polyvinyl alcohol (PVA) and polypyrrole (PPy) that serves as an independent solar vapour generator. The converted energy can be utilized in situ to power the vaporization of water contained in the molecular meshes of the PVA network, where water evaporation is facilitated by the skeleton of the hydrogel. A floating HNG sample evaporated water with a record high rate of 3.2 kg m -2  h -1 via 94% solar energy from 1 sun irradiation, and 18-23 litres of water per square metre of HNG was delivered daily when purifying brine water. These values were achievable due to the reduced latent heat of water evaporation in the molecular mesh under natural sunlight.

Highly efficient solar vapour generation via hierarchically nanostructured gels

NASA Astrophysics Data System (ADS)

Zhao, Fei; Zhou, Xingyi; Shi, Ye; Qian, Xin; Alexander, Megan; Zhao, Xinpeng; Mendez, Samantha; Yang, Ronggui; Qu, Liangti; Yu, Guihua

2018-06-01

Solar vapour generation is an efficient way of harvesting solar energy for the purification of polluted or saline water. However, water evaporation suffers from either inefficient utilization of solar energy or relies on complex and expensive light-concentration accessories. Here, we demonstrate a hierarchically nanostructured gel (HNG) based on polyvinyl alcohol (PVA) and polypyrrole (PPy) that serves as an independent solar vapour generator. The converted energy can be utilized in situ to power the vaporization of water contained in the molecular meshes of the PVA network, where water evaporation is facilitated by the skeleton of the hydrogel. A floating HNG sample evaporated water with a record high rate of 3.2 kg m-2 h-1 via 94% solar energy from 1 sun irradiation, and 18-23 litres of water per square metre of HNG was delivered daily when purifying brine water. These values were achievable due to the reduced latent heat of water evaporation in the molecular mesh under natural sunlight.

Method to protect charge recombination in the back-contact dye-sensitized solar cell.

PubMed

Yoo, Beomjin; Kim, Kang-Jin; Lee, Doh-Kwon; Kim, Kyungkon; Ko, Min Jae; Kim, Yong Hyun; Kim, Won Mok; Park, Nam-Gyu

2010-09-13

We prepared a back-contact dye-sensitized solar cell and investigated effect of the sputter deposited thin TiO₂ film on the back-contact ITO electrode on photovoltaic property. The nanocrystalline TiO₂ layer with thickness of about 11 μm formed on a plain glass substrate in the back-contact structure showed higher optical transmittance than that formed on an ITO-coated glass substrate, which led to an improved photocurrent density by about 6.3%. However, photovoltage was found to decrease from 817 mV to 773 mV. The photovoltage recovered after deposition of a 35 nm-thick thin TiO₂ film on the surface of the back-contact ITO electrode. Little difference in time constant for electron transport was found for the back-contact ITO electrodes with and without the sputter deposited thin TiO₂ film. Whereas, time constant for charge recombination increased after introduction of the thin TiO₂ film, indicating that such a thin TiO₂ film protected back electron transfer, associated with the recovery of photovoltage. As the result of the improved photocurrent density without deterioration of photovoltage, the back-contact dye-sensitized solar cell exhibited 13.6% higher efficiency than the ITO-coated glass substrate-based dye-sensitized solar cell.

Intermediate Bandgap Solar Cells From Nanostructured Silicon

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

Black, Marcie

2014-10-30

This project aimed to demonstrate increased electronic coupling in silicon nanostructures relative to bulk silicon for the purpose of making high efficiency intermediate bandgap solar cells using silicon. To this end, we formed nanowires with controlled crystallographic orientation, small diameter, <111> sidewall faceting, and passivated surfaces to modify the electronic band structure in silicon by breaking down the symmetry of the crystal lattice. We grew and tested these silicon nanowires with <110>-growth axes, which is an orientation that should produce the coupling enhancement.

High-efficiency nanostructured silicon solar cells on a large scale realized through the suppression of recombination channels.

PubMed

Zhong, Sihua; Huang, Zengguang; Lin, Xingxing; Zeng, Yang; Ma, Yechi; Shen, Wenzhong

2015-01-21

Nanostructured silicon solar cells show great potential for new-generation photovoltaics due to their ability to approach ideal light-trapping. However, the nanofeatured morphology that brings about the optical benefits also introduces new recombination channels, and severe deterioration in the electrical performance even outweighs the gain in optics in most attempts. This Research News article aims to review the recent progress in the suppression of carrier recombination in silicon nanostructures, with the emphasis on the optimization of surface morphology and controllable nanostructure height and emitter doping concentration, as well as application of dielectric passivation coatings, providing design rules to realize high-efficiency nanostructured silicon solar cells on a large scale. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Organic photosensitizers with a heteroleptic dual donor for dye-sensitized solar cells.

PubMed

Kim, Joo Young; Kim, Young Sik

2012-04-01

Using DFT and TDDFT calculations, we investigated the substitution effect in the electronic and optical properties of dye sensitizers with a dual donor composed of triphenylamine and/or indoline moieties. Due to replacement with the dual donor moieties, the HOMO levels were split into HOMO and HOMO - 1 levels, and the bandgaps between the HOMO and LUMO levels decreased, leading to the creation of bathochromically extended absorption spectra. Nearly degenerated splitting of the HOMO levels resulted from the similarity of the electronic structure between the HOMO and the HOMO - 1 levels, delocalized over both dual-donor moieties, when replacing the dual donors. It was shown that the additional electron-donating group creates an additional absorption band and causes a cascading two-electron process aiding the charge separation process. Owing to a more panchromatic attribute, easier energy transfer and feasible retardation of the recombination between the injected electrons and the electrolyte, it is expected that dyeTI will show better performance than the other dyes (dyeT dyeTT and dyeIT) as denoted here in terms of the conversion efficiency of dye-sensitized solar cells (DSSCs). This work presents the probable benefits of dye sensitizers with dual-donor moieties and provides insight into the development of more efficient dye sensitizers for DSSCs through modification of the Frontier molecular orbitals.

Effects of nano anatase-rutile TiO2 volume fraction with natural dye containing anthocyanin on the dye sensitized solar cell performance

NASA Astrophysics Data System (ADS)

Agustini, S.; Wahyuono, R. A.; Sawitri, D.; Risanti, D. D.

2013-09-01

Since its first development, efforts to improve efficiency of Dye Sensitized Solar Cell (DSSC) are continuously carried out, either through selection of dye materials, the type of semiconductor, counter electrode design or the sandwiched structure. It is widely known that anatase and rutile are phases of TiO2 that often being used for fabrication of DSSC. Rutile is thermodynamically more stable phase having band-gap suitable for absorption of sunlight spectrum. On the other hand, anatase has higher electrical conductivity, capability to adsorp dye as well as higher electron diffusion coefficient than those of rutile. Present research uses mangosteen pericarp and Rhoeo spathacea extracted in ethanol as natural dye containing anthocyanin. These dyes were characterized by using UV-Vis and FTIR, showing that the absorption maxima peaks obtained at 389 nm and 413 nm, for mangosteen and Rhoeo spathacea, respectively. The nano TiO2 was prepared by means of co-precipitation method. The particle size were 9-11 nm and 54.5 nm for anatase and rutile, respectively, according to Scherrer's equation. DSSCs were fabricated in various volume fractions of anatase and rutile TiO2. The fabricated DSSCs were tested under 17 mW/cm2 of solar irradiation. The current-voltage (I-V) characteristic of DSSCs employing 75%: 25% volume fraction of anatase and rutile TiO2 have outstanding result than others. The highest conversion efficiencies of 0.037% and 0.013% are obtained for DSSC employing natural dye extract from mangosteen pericarp and Rhoeo spathacea, respectively.

Facile preparation of hierarchical nanostructured CuInS2 counter electrodes for dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Dhas, C. Ravi; Christy, A. Jennifer; Venkatesh, R.; Santhoshi Monica, S. Esther; Panda, Subhendu K.; Subramanian, B.; Ravichandran, K.; Sudhagar, P.; Ezhil Raj, A. Moses

2017-12-01

CuInS2 (CIS) thin films have been synthesized onto the glass substrates for different solvent volumes (10, 30, 50 and 70 ml) by nebulizer spray technique. The effect of solvent volume on the structural, morphological, compositional, optical and electrical properties of CIS thin films has been investigated. X-ray diffraction patterns suggest that the obtained CIS films are polycrystalline with the tetragonal structure. The surface morphology of the prepared CIS films purely depends on the solvent volume. The elemental quantitative investigation and the stoichiometric ratio of the CIS thin films were verified from XPS and EDS. High absorbance with the optical band gap of 1.13 eV was obtained at the higher solvent volume. All the deposited CIS thin films exhibited p-type semiconducting behavior with the high electrical conductivity and carrier concentration. CIS thin films deposited onto the FTO substrate were used as a counter electrode (CE) in dye-sensitized solar cells. CIS CEs possessed high electrocatalytic behavior and fast electron charge transfer at the CE/electrolyte interface. The CIS CE prepared using 50 ml solvent volume generated high energy conversion efficiency of about 3.25%.

Charge Transfer Dynamics of Highly Efficient Cyanidin-3-O- Glucoside Sensitizer for Dye-Sensitized Solar Cells

NASA Astrophysics Data System (ADS)

Prima, E. C.; Yuliarto, B.; Suyatman; Dipojono, H. K.

2016-08-01

This paper reports the novel efficiency achievement of black rice-based natural dye- sensitized solar cells. The higher dye concentration, the longer dye extraction as well as dye immersion onto a TiO2 film, and the co-adsorption addition are key strategies for improved-cell performance compared to the highest previous achievement. The black rice dye containing 1.38 mM cyanidin-3-O-glucoside has been extracted without purification for 3 weeks at dark condition and room temperature. The anatase TiO2 photoanode was dipped into dye solution within 4 days. Its electrode was firmly sealed to be a cell and was filled by I-/I3- electrolyte using vacuum technique. As a result, the overall solar-to-energy conversion efficiency was 1.49% at AM 1.5 illumination (100 mW.cm-2). The voltametric analysis has reported the interfacial electronic band edges of TiO2-Dye-Electrolyte. Furthermore, electrochemical impedance spectroscopy has shown the kinetic of interfacial electron transfer dynamics among TiO2-dye-electrolyte. The cell has the transfer resistance (Rt) of 12.5 ω, the recombination resistance (Rr) of 266.8 ω, effective electron diffusion coefficients (Dn) of 1.4 × 10-3 cm2/s, Dye-TiO2 effective electron transfer (τd) of 26.6 μs, effective diffusion length (Ln)of 33.78 μm, chemical capacitance (Cμ) of 12.43 μF, and electron lifetime (τn) of 3.32 ms.

A versatile chemical conversion synthesis of Cu2S nanotubes and the photovoltaic activities for dye-sensitized solar cell

PubMed Central

2014-01-01

A versatile, low-temperature, and low-cost chemical conversion synthesis has been developed to prepare copper sulfide (Cu2S) nanotubes. The successful chemical conversion from ZnS nanotubes to Cu2S ones profits by the large difference in solubility between ZnS and Cu2S. The morphology, structure, and composition of the yielded products have been examined by field-emission scanning electron microscopy, transmission electron microscopy, and X-ray diffraction measurements. We have further successfully employed the obtained Cu2S nanotubes as counter electrodes in dye-sensitized solar cells. The light-to-electricity conversion results show that the Cu2S nanostructures exhibit high photovoltaic conversion efficiency due to the increased surface area and the good electrocatalytical activity of Cu2S. The present chemical route provides a simple way to synthesize Cu2S nanotubes with a high surface area for nanodevice applications. PMID:25246878

Dye Oriza sativa glutinosa doped Fe as a active element of Dye Sensitized Solar Cell (DSSC)

NASA Astrophysics Data System (ADS)

Prasada, A. B.; Fadli, U. M.; Cari; Supriyanto, A.

2016-11-01

The aims of the research are to determine the effect of doping Fe (III) Sulphate into dye Oriza sativa glutinosa on the characteristics parameters of solar cells, to determine the optical characteristic, functional group and electrical characteristic of dye Oriza sativa glutinosa doped Fe (III) sulphate. TiO2 nano size as much as 0.5 gr dissolved in 3 ml ethanol. 100 gr black sticky rice (Oriza sativa glutinosa) was immersed in 80 ml ethanol solution (95%) and kept at room temperature without exposing to light. Then it was filtered with a filter paper no.42, and the extracted result was process with chromatography. Furthermore, it was doped with Fe (III) sulphate respectively of 10-1 M, 10-2 M, 10-3 M. The characteristic of dye solution was measured using UV-Visible Spectrophotometer Lambda 25 for absorbance, Elkahfi 100/I-V meter for conductivity amd Keithey 2602A for characterization of current and voltage (I-V). The result showed that the area of dye Oriza sativa glutionosa doped Fe (III) sulphate with concentration 10-1 M the largest, because the value of Voc intercept at 6.40 × 10-1 mV and the value Isc intercept at 1.89 × 10-3 mA, with efficiency value is 0.148%.

Energy relay from an unconventional yellow dye to CdS/CdSe quantum dots for enhanced solar cell performance.

PubMed

Narayanan, Remya; Das, Amrita; Deepa, Melepurath; Srivastava, Avanish Kumar

2013-12-02

A new design for a quasi-solid-state Forster resonance energy transfer (FRET) enabled solar cell with unattached Lucifer yellow (LY) dye molecules as donors and CdS/CdSe quantum dots (QDs) tethered to titania (TiO2 ) as acceptors is presented. The Forster radius is experimentally determined to be 5.29 nm. Sequential energy transfer from the LY dye to the QDs and electron transfer from the QDs to TiO2 is followed by fluorescence quenching and electron lifetime studies. Cells with a donor-acceptor architecture (TiO2 /CdS/CdSe/ZnS-LY/S(2-)-multi-walled carbon nanotubes) show a maximum incident photon-to-current conversion efficiency of 53 % at 530 nm. This is the highest efficiency among Ru-dye free FRET-enabled quantum dot solar cells (QDSCs), and is much higher than the donor or acceptor-only cells. The FRET-enhanced solar cell performance over the majority of the visible spectrum paves the way to harnessing the untapped potential of the LY dye as an energy relay fluorophore for the entire gamut of dye sensitized, organic, or hybrid solar cells. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Novel Blue Organic Dye for Dye-Sensitized Solar Cells Achieving High Efficiency in Cobalt-Based Electrolytes and by Co-Sensitization.

PubMed

Hao, Yan; Saygili, Yasemin; Cong, Jiayan; Eriksson, Anna; Yang, Wenxing; Zhang, Jinbao; Polanski, Enrico; Nonomura, Kazuteru; Zakeeruddin, Shaik Mohammed; Grätzel, Michael; Hagfeldt, Anders; Boschloo, Gerrit

2016-12-07

Blue and green dyes as well as NIR-absorbing dyes have attracted great interest because of their excellent ability of absorbing the incident photons in the red and near-infrared range region. A novel blue D-π-A dye (Dyenamo Blue), based on the diketopyrrolopyrrole (DPP)-core, has been designed and synthesized. Assembled with the cobalt bipyridine-based electrolytes, the device with Dyenamo Blue achieved a satisfying efficiency of 7.3% under one sun (AM1.5 G). The co-sensitization strategy was further applied on this blue organic dye together with a red D-π-A dye (D35). The successful co-sensitization outperformed a panchromatic light absorption and improved the photocurrent density; this in addition to the open-circuit potential result in an efficiency of 8.7%. The extended absorption of the sensitization and the slower recombination reaction between the blue dye and TiO 2 surface inhibited by the additional red sensitizer could be the two main reasons for the higher performance. In conclusion, from the results, the highly efficient cobalt-based DSSCs could be achieved with the co-sensitization between red and blue D-π-A organic dyes with a proper design, which showed us the possibility of applying this strategy for future high-performance solar cells.

Development of nanostructured and surface modified semiconductors for hybrid organic-inorganic solar cells.

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

Hsu, Julia, W. P.

2008-09-01

Solar energy conversion is increasingly being recognized as one of the principal ways to meet future energy needs without causing detrimental environmental impact. Hybrid organic-inorganic solar cells (SCs) are attracting particular interest due to the potential for low cost manufacturing and for use in new applications, such as consumer electronics, architectural integration and light-weight sensors. Key materials advantages of these next generation SCs over conventional semiconductor SCs are in design opportunities--since the different functions of the SCs are carried out by different materials, there are greater materials choices for producing optimized structures. In this project, we explore the hybrid organic-inorganicmore » solar cell system that consists of oxide, primarily ZnO, nanostructures as the electron transporter and poly-(3-hexylthiophene) (P3HT) as the light-absorber and hole transporter. It builds on our capabilities in the solution synthesis of nanostructured semiconducting oxide arrays to this photovoltaic (PV) technology. The three challenges in this hybrid material system for solar applications are (1) achieving inorganic nanostructures with critical spacing that matches the exciton diffusion in the polymer, {approx} 10 nm, (2) infiltrating the polymer completely into the dense nanostructure arrays, and (3) optimizing the interfacial properties to facilitate efficient charge transfer. We have gained an understanding and control over growing oriented ZnO nanorods with sub-50 nm diameters and the required rod-to-rod spacing on various substrates. We have developed novel approaches to infiltrate commercially available P3HT in the narrow spacing between ZnO nanorods. Also, we have begun to explore ways to modify the interfacial properties. In addition, we have established device fabrication and testing capabilities at Sandia for prototype devices. Moreover, the control synthesis of ZnO nanorod arrays lead to the development of an efficient anti

Efficiency enhancement of dye-sensitized solar cells by use of ZrO2-doped TiO2 nanofibers photoanode.

PubMed

Mohamed, Ibrahim M A; Dao, Van-Duong; Barakat, Nasser A M; Yasin, Ahmed S; Yousef, Ahmed; Choi, Ho-Suk

2016-08-15

Due to the good stability and convenient optical properties, TiO2 nanostructures still the prominent photoanode materials in the Dye Sensitized Solar Cells (DSCs). However, the well-known low bandgap energy and weak adsorption affinity for the dye distinctly constrain the wide application. This work discusses the impact of Zr-doping and nanofibrous morphology on the performance and physicochemical properties of TiO2. Zr-doped TiO2 nanofibers (NFs), with various zirconia content (0, 0.5, 1, 1.5 and 2wt%) were prepared by calcination of electrospun mats composed of polyvinyl acetate, titanium isopropoxyl and zirconium n-propoxyl. For all formulations, the results have shown that the prepared materials are continuous, randomly oriented, and good morphology nanofibers. The average diameter decreased from 353.85nm to 210.78nm after calcination without a considerable influence on the nanofibrous structure regardless the zirconia content. XRD result shows that there is no Rutile nor Brookite phases in the obtained material and the average crystallite size of the sample is affected by the presence of Zr-doping and changed from 23.01nm to 37.63nm for TiO2 and Zr-doped TiO2, respectively. Optical studies have shown Zr-doped TiO2 NFs have more absorbance in the visible region than that of pristine TiO2 NFs; the maximum absorbance is corresponding to the NFs having 1wt% zirconia. The improved spectra of Zr-doped TiO2 in the visible region is attributed to the heterostructure composition resulting from Zr-doping. The absorption bandgaps were calculated using Tauc model as 3.202 and 3.217 for pristine and Zr (1wt%)-doped TiO2 NFs, respectively. Furthermore, in Dye-sensitized Solar Cells, utilizing Zr (1wt%)-doped TiO2 nanofibers achieved higher efficiency of 4.51% compared to the 1.61% obtained from the pristine TiO2 NFs. Copyright © 2016 Elsevier Inc. All rights reserved.

Template Free Architecture of Hierarchical Nanostructured ZnIn₂S₄ Rose-Like Flowers for Solar Hydrogen Production.

PubMed

Kale, Bharat B; Bhirud, Ashwini P; Baeg, Jin-Ook; Kulkarni, Milind V

2017-02-01

We have demonstrated the controlled synthesis of hierarchical nanostructured ZnIn₂S₄ using a facile template free hydrothermal/solvothermal method. The effect of solvents on the morphology and microstructure of ZnIn₂S₄ has been studied by using water, methanol and ethylene glycol as a solvents. The hierarchical nanostructure, i.e., rose-like morphology composed of very thin (5–6 nm) nanoplates of length ˜1 μm which was obtained in aqueous mediated ZnIn₂S₄. The porous structure (distorted flowers) and agglomerated nanoparticles were obtained using methanol-and ethylene glycol-mediated ZnIn₂S₄. Considering the band gap in the visible region, ZnIn₂S₄ is used as a solar light driven photocatalyst. An ecofriendly photocatalytic process for the conversion of poisonous H₂S into H₂ which is a green unconventional energy source has been demonstrated. The nanostructured ZnIn₂S₄ is employed as a photocatalyst for hydrogen production from H₂S via a solar light-driven eco-friendly approach. The stable photocatalytic activity of hydrogen evolution, i.e., 3964 μmol ⁻¹ was obtained using 0.5 gm of such hierarchical nanostructured ZnIn₂S₄ under visible light irradiation. The unique hierarchical nanostructured ZnIn₂S₄ ternary semiconductor having hexagonal layer is expected to have potential applications in solar cells, LEDs, charge storage, electrochemical recording, thermoelectricity, other prospective electronic and optical devices.

Analysis of Chameleonic Change of Red Cabbage Depending on Broad pH Range for Dye-Sensitized Solar Cells.

PubMed

Park, Kyung Hee; Kim, Tae Young; Ko, Hyun Seok; Han, Eun Mi; Lee, Suk-Ho; Kim, Jung-Hun; Lee, Jae Wook

2015-08-01

Dye-sensitized solar cells (DSSCs) were assembled using natural dyes extracted from red cabbage as a sensitizer. In this work, we investigated the adsorption characteristics and the electrochemical behavior for harvesting sunlight and electron transfer in red cabbage DSSCs under different solvents and pH. For the red cabbage dye-sensitized electrode adsorbed at pH 3.5, the solar cell yields a short-circuit current density (Jsc) of 1.60 mA/cm2, a photovoltage (Vcc) of 0.46 V, and a fill factor of 0.55, corresponding to an energy conversion efficiency (η) of 0.41%.

Sprayed nanostructured TiO2 films for efficient photocatalytic degradation of textile azo dye.

PubMed

Stambolova, Irina; Shipochka, Capital Em Cyrillicaria; Blaskov, Vladimir; Loukanov, Alexandrе; Vassilev, Sasho

2012-12-05

Spray pyrolysis procedure for preparation of nanostructured TiO(2) films with higher photocatalytic effectiveness and longer exploitation life is presented in this study. Thin films of active nanocrystalline TiO(2) were obtained from titanium isopropoxide, stabilized with acetyl acetone and characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The activity of sprayed nanostructured TiO(2) is tested for photocatalytic degradation of Reactive Black 5 dye with concentrations up to 80 ppm. Interesting result of the work is the reduction of toxicity after photocatalytic treatment of RB5 with TiO(2), which was confirmed by the lower percentage of mortality of Artemia salina. It was proved that the film thickness, conditions of post deposition treatment and the type of the substrate affected significantly the photocatalytic reaction. Taking into account that the parameters are interdependent, it is necessary to optimize the preparation conditions in order to synthesize photocatalytic active films. Copyright © 2012 Elsevier B.V. All rights reserved.

One-Dimensional Metal-Oxide Nanostructures for Solar Photocatalytic Water-Splitting

NASA Astrophysics Data System (ADS)

Wang, Fengyun; Song, Longfei; Zhang, Hongchao; Luo, Linqu; Wang, Dong; Tang, Jie

2017-08-01

Because of their unique physical and chemical properties, one-dimensional (1-D) metal-oxide nanostructures have been extensively applied in the areas of gas sensors, electrochromic devices, nanogenerators, and so on. Solar water-splitting has attracted extensive research interest because hydrogen generated from solar-driven water splitting is a clean, sustainable, and abundant energy source that not only solves the energy crisis, but also protects the environment. In this comprehensive review, the main synthesis methods, properties, and especially prominent applications in solar water splitting of 1-D metal-oxides, including titanium dioxide (TiO2), zinc oxide (ZnO), tungsten trioxide (WO3), iron oxide (Fe2O3), and copper oxide (CuO) are fully discussed.

Photovoltaic studies of Dye Sensitized Solar cells Fabricated from Microwave Exposed Photo anodes

NASA Astrophysics Data System (ADS)

Ramachandran, Anju; Sreekala, C. O.; Sreelatha, K. S.; Jinchu, I.

2018-02-01

The configuration of Dye Sensitized solar cells (DSSC), consists of sintered nanoparticle titanium dioxide film, dyes, electrolyte and counter electrodes. Upon the absorption of photons by the dye molecules, excitons are generated, subsequently electrons are injected into the TiO2 photoanode. Afterward the electrons injected into the TiO2 photoanode, to produce photocurrent, scavenged by redox couple, and the hole transport to the photo cathode. The power conversion efficiency of the device depends on the amount of dye adsorbed by the photoanode. This paper explores in enhancing the efficiency of the device by controlled microwave exposure. With same exposure time, the photoanode is exposed at three different frequencies. SEM analysis is carried out to find the porosity of the photoanode on exposure. Current density is found to have an effect on microwave exposure.

Experimental elaboration and analysis of dye-sensitized TiO2 solar cells (DSSC) dyed by natural dyes and conductive polymers

NASA Astrophysics Data System (ADS)

KałuŻyński, P.; Maciak, E.; Herzog, T.; Wójcik, M.

2016-09-01

In this paper we propose low cost and easy in development fully working dye-sensitized solar cell module made with use of a different sensitizing dyes (various anthocyanins and P3HT) for increasing the absorption spectrum, transparent conducting substrates (vaccum spattered chromium and gold), nanometer sized TiO2 film, iodide and methyl viologen dichloride based electrolyte, and a counter electrode (vaccum spattered platinum or carbon). Moreover, some of the different technologies and optimization manufacturing processes were elaborated for energy efficiency increase and were presented in this paper.

New dye-sensitized solar cells obtained from extracted bracts of Bougainvillea glabra and spectabilis betalain pigments by different purification processes.

PubMed

Hernandez-Martinez, Angel Ramon; Estevez, Miriam; Vargas, Susana; Quintanilla, Fracisco; Rodriguez, Rogelio

2011-01-01

The performance of a new dye-sensitized solar cell (DSSC) based in a natural dye extracted from the Bougainvillea spectabilis' bracts, is reported. The performance of this solar cell was compared with cells prepared using extract of the Bougainvillea glabra and mixture of both extracts; in both cases the pigments were betalains, obtained from Reddish-purple extract. These dyes were purified to different extents and used for the construction of solar cells that were electrically characterized. The materials were characterized using FTIR and UV-Vis. Solar cells were assembled using TiO(2) thin film on indium tin oxide (ITO)-coated glass; a mesoporous film was sensitized with the Bougainvillea extracts. The obtained solar energy conversion efficiency was of 0.48% with a current density J(SC) of 2.29 mA/cm(2) using an irradiation of 100 mW/cm(2) at 25 °C.

New Dye-Sensitized Solar Cells Obtained from Extracted Bracts of Bougainvillea Glabra and Spectabilis Betalain Pigments by Different Purification Processes

PubMed Central

Hernandez-Martinez, Angel Ramon; Estevez, Miriam; Vargas, Susana; Quintanilla, Fracisco; Rodriguez, Rogelio

2011-01-01

The performance of a new dye-sensitized solar cell (DSSC) based in a natural dye extracted from the Bougainvillea spectabilis’ bracts, is reported. The performance of this solar cell was compared with cells prepared using extract of the Bougainvillea glabra and mixture of both extracts; in both cases the pigments were betalains, obtained from Reddish-purple extract. These dyes were purified to different extents and used for the construction of solar cells that were electrically characterized. The materials were characterized using FTIR and UV-Vis. Solar cells were assembled using TiO2 thin film on indium tin oxide (ITO)-coated glass; a mesoporous film was sensitized with the Bougainvillea extracts. The obtained solar energy conversion efficiency was of 0.48% with a current density JSC of 2.29 mA/cm2 using an irradiation of 100 mW/cm2 at 25 °C. PMID:22016609

Studies on the optical and photoelectric properties of anthocyanin and chlorophyll as natural co-sensitizers in dye sensitized solar cell

NASA Astrophysics Data System (ADS)

Nan, Hui; Shen, He-Ping; Wang, Gang; Xie, Shou-Dong; Yang, Gui-Jun; Lin, Hong

2017-11-01

Anthocyanin and Chlorophyll extracted from Troll flower and Cypress leaf respectively are used as natural sensitizers in dye sensitized solar cells (DSCs), with their optical and electrochemical properties investigated. UV-Vis absorption measurement showed that the mixture of two dyes enabled an enhanced and wider absorption in the wavelength range of 300 nm-700 nm compared to each single dye. FTIR results proved that anthocyanin is chemically adsorbed onto the TiO2 film, while it is physical adsorption for chlorophyll. The energy level offsets on the TiO2/dye/electrolyte interface for each dye and the dye mixture with different ratios were calculated from the electrochemical analysis, which affect the electron injection and dye regeneration efficiencies. The optimized ratio of the two dyes in the mixture was found to be ∼2:5, inducing both sufficient charge transfer driving force and minimal energy loss. By incorporating this mixture into the solar cell as co-adsorbing sensitizer, the photovoltaic performance was prominently improved compared with the single dye sensitization system.

Spin-based diagnostic of nanostructure in copper phthalocyanine-C60 solar cell blends.

PubMed

Warner, Marc; Mauthoor, Soumaya; Felton, Solveig; Wu, Wei; Gardener, Jules A; Din, Salahud; Klose, Daniel; Morley, Gavin W; Stoneham, A Marshall; Fisher, Andrew J; Aeppli, Gabriel; Kay, Christopher W M; Heutz, Sandrine

2012-12-21

Nanostructure and molecular orientation play a crucial role in determining the functionality of organic thin films. In practical devices, such as organic solar cells consisting of donor-acceptor mixtures, crystallinity is poor and these qualities cannot be readily determined by conventional diffraction techniques, while common microscopy only reveals surface morphology. Using a simple nondestructive technique, namely, continuous-wave electron paramagnetic resonance spectroscopy, which exploits the well-understood angular dependence of the g-factor and hyperfine tensors, we show that in the solar cell blend of C(60) and copper phthalocyanine (CuPc)-for which X-ray diffraction gives no information-the CuPc, and by implication the C(60), molecules form nanoclusters, with the planes of the CuPc molecules oriented perpendicular to the film surface. This information demonstrates that the current nanostructure in CuPc:C(60) solar cells is far from optimal and suggests that their efficiency could be considerably increased by alternative film growth algorithms.

Enhanced light absorption in an ultrathin silicon solar cell utilizing plasmonic nanostructures

NASA Astrophysics Data System (ADS)

Xiao, Sanshui; Mortensen, Niels A.

2012-10-01

Nowadays, bringing photovoltaics to the market is mainly limited by high cost of electricity produced by the photovoltaic solar cell. Thin-film photovoltaics offers the potential for a significant cost reduction compared to traditional photovoltaics. However, the performance of thin-film solar cells is generally limited by poor light absorption. We propose an ultrathin-film silicon solar cell configuration based on SOI structure, where the light absorption is enhanced by use of plasmonic nanostructures. By placing a one-dimensional plasmonic nanograting on the bottom of the solar cell, the generated photocurrent for a 200 nm-thickness crystalline silicon solar cell can be enhanced by 90% in the considered wavelength range. These results are paving a promising way for the realization of high-efficiency thin-film solar cells.

Photo-sensitization of ZnS nanoparticles with renowned ruthenium dyes N3, N719 and Z907 for application in solid state dye sensitized solar cells: A comparative study.

PubMed

Nosheen, Erum; Shah, Syed Mujtaba; Hussain, Hazrat; Murtaza, Ghulam

2016-09-01

This article presents a comprehensive relative report on the grafting of ZnS with renowned ruthenium ((Ru) dyes i.e. N3, N719 and Z907) and gives insight into their charge transfer interaction and sensitization mechanism for boosting solar cell efficiency. Influence of dye concentration on cell performance is also reported here. ZnS nanoparticles synthesized by a simple coprecipitation method with an average particle size of 15±2nm were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Elemental dispersive X-ray analysis (EDAX), tunneling electron microscopy (TEM) and UV-Visible (UV-Vis) spectroscopy. UV-Vis, photoluminescence (PL) and Fourier transform infra-red (FT-IR) spectroscopy confirms the successful grafting of these dyes over ZnS nanoparticles surface. Low-energy metal-to-ligand charge-transfer transition (MLCT) bands of dyes are mainly affected on grafting over the nanoparticle surface. Moreover their current voltage (I-V) results confirm the efficiency enhancement in ZnS solid state dye sensitized solar cells (SSDSSCs) owing to effective sensitization of this material with Ru dyes and helps in finding the optimum dye concentration for nanoparticles sensitization. Highest rise in overall solar cell efficiency i.e. 64% of the reference device has been observed for 0.3mM N719-ZnS sample owing to increased open circuit voltage (Voc) and fill factor (FF). Experimental and proposed results were found in good agreement with each other. Copyright © 2016 Elsevier B.V. All rights reserved.

Temperature effect of natural organic extraction upon light absorbance in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Suhaimi, Suriati; Mohamed Siddick, Siti Zubaidah; Retnasamy, Vithyacharan; Abdul Wahid, Mohamad Halim; Ahmad Hambali, Nor Azura Malini; Mohamad Shahimin, Mukhzeer

2017-02-01

Natural organic dyes contain pigments which when safely extracted from plants have the potential to be used as a sensitizer while promising a low-cost fabrication, environmental friendly dye-sensitized solar cells (DSSCs). Ardisia, Bawang Sabrang, Harum Manis mango, Oxalis Triangularis and Rosella showed different absorption peaks when the extraction process were carried out at different temperatures. Hence, these were used as the basis to determine the conversion efficiency against the dyes extracting temperature. In this study, all dyes extracted in water have shown the best performance at a temperature of 100°C except for Harum Manis mango, while in ethanol, the optimum temperature was obtained between the room temperature, 25°C and 50°C. The absorption spectrum in water showed a broader absorption wavelength vis-à-vis ethanol solvent that resulted in the absorption peak for Ardisia, Harum Manis mango and Rosella between 450 nm and 550 nm. The highest conversion efficiency is observed to be achieved by Oxalis Triangularis extracted in water solution at 100°C, which was approximately 0.96% which corresponds to the broader absorbance trends in the literature. Thus, the optimum condition for extracting temperature for dyes in water and ethanol is room temperature and boiling points of water. Hence, Ardisia, Bawang Sabrang, Harum Manis mango, Oxalis Triangularis and Rosella can be an as alternative source for photosensitizer, and the impacts of temperature upon the light absorbance can be further investigated to produce the ultimate natural dye based solar cells.

Photocurrent generation by dye-sensitized solar cells using natural pigments.

PubMed

Armendáriz-Mireles, Eddie Nahúm; Rocha-Rangel, Enrique; Caballero-Rico, Frida; Ramírez-de-León, José Alberto; Vázquez, Manuel

2017-01-01

The development of photovoltaic panels has improved the conversion of solar radiation into electrical energy. This paper deals with the electrical and thermal characteristics (voltage, current, and temperature) of photovoltaic solar cells sensitized with natural pigments (dye-sensitized solar cell, DSSC) based on a titanium dioxide semiconductor. Several natural pigments (blackberry, beets, eggplant skin, spinach, flame tree flower, papaya leaf, and grass extracts) were evaluated to determine their sensitizing effect on titanium dioxide. The results showed the great potential of natural pigments for use in solar cells. The best results were obtained with the blackberry pigment, reaching a value of 7.1 mA current, open-circuit voltage (V oc ) of 0.72 V in 2 cm 2 , and fill factor (ff) of 0.51 in the DSSC. This performance is well above than that currently offers by actual cells. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

Investigation of the influence of coadsorbent dye upon the interfacial structure of dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Honda, M.; Yanagida, M.; Han, L.; Miyano, K.

2014-11-01

The interface between Ru(tcterpy)(NCS)3TBA2 [black dye (BD); tcterpy = 4,4',4″-tricarboxy-2,2':6',2″-terpyridine, NCS = thiocyanato, TBA = tetrabutylammonium cation] and nanocrystalline TiO2, as found in dye-sensitized solar cells, is investigated by soft-X-ray synchrotron radiation and compared with the adsorption structure of cis-Ru(Hdcbpy)2(NCS)2TBA2 (N719; dcbpy = 4,4'-dicarboxy-2,2'-bipyridine) on TiO2 to elucidate the relationship between the adsorption mode of BD and the photocurrent with and without coadsorbed indoline dye D131. The depth profile is characterized with X-ray photoelectron spectroscopy and S K-edge X-ray absorption fine structure using synchrotron radiation. Both datasets indicate that one of the isothiocyanate groups of BD interacts with TiO2 via its S atom when the dye is adsorbed from a single-component solution. In contrast, the interaction is slightly suppressed when D131 is coadsorbed, indicated by the fact that the presence of D131 changes the adsorption mode of BD. Based upon these results, the number of BD dye molecules interacting with the substrate is shown to decrease by 10% when D131 is coadsorbed, and the dissociation is shown to be related to the short-circuit photocurrent in the 600-800 nm region. The design of a procedure to promote the preferential adsorption of D131 therefore leads to an improvement of the short-circuit current and conversion efficiency.

The design, fabrication, and photocatalytic utility of nanostructured semiconductors: focus on TiO2-based nanostructures

PubMed Central

Banerjee, Arghya Narayan

2011-01-01

Recent advances in basic fabrication techniques of TiO2-based nanomaterials such as nanoparticles, nanowires, nanoplatelets, and both physical- and solution-based techniques have been adopted by various research groups around the world. Our research focus has been mainly on various deposition parameters used for fabricating nanostructured materials, including TiO2-organic/inorganic nanocomposite materials. Technically, TiO2 shows relatively high reactivity under ultraviolet light, the energy of which exceeds the band gap of TiO2. The development of photocatalysts exhibiting high reactivity under visible light allows the main part of the solar spectrum to be used. Visible light-activated TiO2 could be prepared by doping or sensitizing. As far as doping of TiO2 is concerned, in obtaining tailored material with improved properties, metal and nonmetal doping has been performed in the context of improved photoactivity. Nonmetal doping seems to be more promising than metal doping. TiO2 represents an effective photocatalyst for water and air purification and for self-cleaning surfaces. Additionally, it can be used as an antibacterial agent because of its strong oxidation activity and superhydrophilicity. Therefore, applications of TiO2 in terms of photocatalytic activities are discussed here. The basic mechanisms of the photoactivities of TiO2 and nanostructures are considered alongside band structure engineering and surface modification in nanostructured TiO2 in the context of doping. The article reviews the basic structural, optical, and electrical properties of TiO2, followed by detailed fabrication techniques of 0-, 1-, and quasi-2-dimensional TiO2 nanomaterials. Applications and future directions of nanostructured TiO2 are considered in the context of various photoinduced phenomena such as hydrogen production, electricity generation via dye-sensitized solar cells, photokilling and self-cleaning effect, photo-oxidation of organic pollutant, wastewater management, and

Optical determination of charge transfer times from indoline dyes to ZnO in solid state dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Meyenburg, I.; Hofeditz, N.; Ruess, R.; Rudolph, M.; Schlettwein, D.; Heimbrodt, W.

2018-05-01

We studied the electron transfer at the interface of organic-inorganic hybrids consisting of indoline derivatives (D149 and D131) on ZnO substrates using a new optical method. We revealed the electron transfer times from the excited dye, e.g. the excitons formed in the dye aggregates to the ZnO substrate by analyzing the photoluminescence transients of the excitons after femtosecond excitation and applying kinetic model calculations. We reveal the changes of the electron transfer times by applying electrical bias. Pushing the Fermi energy of the ZnO substrate towards the excited dye level the transfer time gets longer and eventually the electron transfer is suppressed. The level alignment between the excited dye state and the ZnO Fermi-level is estimated. The excited state of D131 is about 100 meV higher than the respective state of D149 compared to the ZnO conduction band. This leads to shorter electron transfer times and eventually to higher quantum efficiencies of the solar cells.

Revealing the influence of Cyano in Anchoring Groups of Organic Dyes on Adsorption Stability and Photovoltaic Properties for Dye-Sensitized Solar Cells.

PubMed

Chen, Wei-Chieh; Nachimuthu, Santhanamoorthi; Jiang, Jyh-Chiang

2017-07-10

Determining an ideal adsorption configuration for a dye on the semiconductor surface is an important task in improving the overall efficiency of dye-sensitized solar cells. Here, we present a detailed investigation of different adsorption configurations of designed model dyes on TiO 2 anatase (101) surface using first principles methods. Particularly, we aimed to investigate the influence of cyano group in the anchoring part of dye on its adsorption stability and the overall photovoltaic properties such as open circuit voltage, electron injection ability to the surface. Our results indicate that the inclusion of cyano group increases the stability of adsorption only when it adsorbs via CN with the surface and it decreases the photovoltaic properties when it does not involve in binding. In addition, we also considered full dyes based on the results of model dyes and investigated the different strength of acceptor abilities on stability and electron injection ability. Among the various adsorption configurations considered here, the bidentate bridging mode (A3) is more appropriate one which has higher electron injection ability, larger V OC value and more importantly it has higher dye loading on the surface.

Fabrication and Characterization of Sansevieria trifasciata, Pandanus amaryllifolius and Cassia angustifolia as Photosensitizer for Dye Sensitized Solar Cells

NASA Astrophysics Data System (ADS)

Cari; Supriyanto, Agus; Mahfudli Fadli, Ulfa; Bayu Prasada, Ashari

2016-04-01

Dye sensitized Solar Cells (DSSC) is one of the electric cells photochemical consisting of photoelectrode, dye, counter electrode, and electrolyte. The aims of the research to determine of the optical and electrical characteristic of the extract Sansevieria trifasciata, Pandanus amaryllifolius, and Cassia angustifolia. The study is also aimed to determine the effect of natural dyes extract to increase the efficiency of solar cells based DSSC. Sandwich structures formed in the sample consisted of working electrode pair Titanium dioxide (TiO2) and the counter electrode platinum (Pt). Dye extraction process is performed by stirring for 1 hour and then allowed to stand for 24 hours. Absorbance test is measure by using UV-Vis spectrophotometer Lambda 25, conductivity test by using a two-point probes Elkahfi 100, and characterization of current and voltage (I-V) by using a Keithley 2602A. The results showed that the greatest efficiency of 0.160% at Dye Pandanus amaryllifolius.

Modeling and Optimization of Sub-Wavelength Grating Nanostructures on Cu(In,Ga)Se2 Solar Cell

NASA Astrophysics Data System (ADS)

Kuo, Shou-Yi; Hsieh, Ming-Yang; Lai, Fang-I.; Liao, Yu-Kuang; Kao, Ming-Hsuan; Kuo, Hao-Chung

2012-10-01

In this study, an optical simulation of Cu(In,Ga)Se2 (CIGS) solar cells by the rigorous coupled-wave analysis (RCWA) method is carried out to investigate the effects of surface morphology on the light absorption and power conversion efficiencies. Various sub-wavelength grating (SWG) nanostructures of periodic ZnO:Al (AZO) on CIGS solar cells were discussed in detail. SWG nanostructures were used as efficient antireflection layers. From the simulation results, AZO structures with nipple arrays effectively suppress the Fresnel reflection compared with nanorod- and cone-shaped AZO structures. The optimized reflectance decreased from 8.44 to 3.02% and the efficiency increased from 14.92 to 16.11% accordingly. The remarkable enhancement in light harvesting is attributed to the gradient refractive index profile between the AZO nanostructures and air.

A home-made system for IPCE measurement of standard and dye-sensitized solar cells.

PubMed

Palma, Giuseppina; Cozzarini, Luca; Capria, Ennio; Fraleoni-Morgera, Alessandro

2015-01-01

A home-made system for incident photon-to-electron conversion efficiency (IPCE) characterization, based on a double-beam UV-Vis spectrophotometer, has been set up. In addition to its low cost (compared to the commercially available apparatuses), the double-beam configuration gives the advantage to measure, autonomously and with no need for supplementary equipment, the lamp power in real time, compensating possible variations of the spectral emission intensity and quality, thus reducing measurement times. To manage the optical and electronic components of the system, a custom software has been developed. Validations carried out on a common silicon-based photodiode and on a dye-sensitized solar cell confirm the possibility to adopt this system for determining the IPCE of solar cells, including dye-sensitized ones.

Integration of Light Trapping Silver Nanostructures in Hydrogenated Microcrystalline Silicon Solar Cells by Transfer Printing

PubMed Central

Mizuno, Hidenori; Sai, Hitoshi; Matsubara, Koji; Takato, Hidetaka; Kondo, Michio

2015-01-01

One of the potential applications of metal nanostructures is light trapping in solar cells, where unique optical properties of nanosized metals, commonly known as plasmonic effects, play an important role. Research in this field has, however, been impeded owing to the difficulty of fabricating devices containing the desired functional metal nanostructures. In order to provide a viable strategy to this issue, we herein show a transfer printing-based approach that allows the quick and low-cost integration of designed metal nanostructures with a variety of device architectures, including solar cells. Nanopillar poly(dimethylsiloxane) (PDMS) stamps were fabricated from a commercially available nanohole plastic film as a master mold. On this nanopatterned PDMS stamps, Ag films were deposited, which were then transfer-printed onto block copolymer (binding layer)-coated hydrogenated microcrystalline Si (µc-Si:H) surface to afford ordered Ag nanodisk structures. It was confirmed that the resulting Ag nanodisk-incorporated µc-Si:H solar cells show higher performances compared to a cell without the transfer-printed Ag nanodisks, thanks to plasmonic light trapping effect derived from the Ag nanodisks. Because of the simplicity and versatility, further device application would also be feasible thorough this approach. PMID:26575244

EXAFS, ab Initio Molecular Dynamics, and NICIS Spectroscopy Studies on an Organic Dye Model at the Dye-Sensitized Solar Cell Photoelectrode Interface.

PubMed

Liu, Peng; Johansson, Viktor; Trilaksana, Herri; Rosdahl, Jan; Andersson, Gunther G; Kloo, Lars

2017-06-14

The organization of dye molecules in the dye layer adsorbed on the semiconductor substrate in dye-sensitized solar cells has been studied using a combination of theoretical methods and experimental techniques. The model system is based on the simple D-π-A dye L0, which has been chemically modified by substituting the acceptor group CN with Br (L0Br) to offer better X-ray contrast. Experimental EXAFS data based on the Br K-edge backscattering show no obvious difference between dye-sensitized titania powder and titania film samples, thus allowing model systems to be based on powder slurries. Ab initio molecular dynamic (aiMD) calculations have been performed to extract less biased information from the experimental EXASF data. Using the aiMD calculation as input, the EXAFS structural models can be generated a priori that match the experimental data. Our study shows that the L0Br dye adsorbs in the trans-L0Br configuration and that adsorption involves both a proximity to other L0Br dye molecules and the titanium atoms in the TiO 2 substrate. These results indicate direct coordination of the dye molecules to the TiO 2 surface in contrast to previous results on metal-organic dyes. The molecular coverage of L0Br on mesoporous TiO 2 was also estimated using NICIS spectroscopy. The NICISS results emphasized that the L0Br dye on nanoporous titania mainly forms monolayers with a small contribution of multilayer coverage.

Fabrication, characterization of two nano-composite CuO-ZnO working electrodes for dye-sensitized solar cell.

PubMed

Habibi, Mohammad Hossein; Karimi, Bahareh; Zendehdel, Mahmoud; Habibi, Mehdi

2013-12-01

Two kind of CuO-ZnO nanocomposite working electrodes were synthesized by sol-gel technology and applied in dye-sensitized solar cells (DSSCs). Their characteristics were studied by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and UV-Vis diffuse reflectance spectrum (DRS). CuO-ZnO nanocomposite thin films were prepared doctor blade technique on the fluorine-doped tin oxide (FTO) and used as working electrodes in dye sensitized solar cells (DSSC). Their photovoltaic behavior were compared with standard using D35 dye and an electrolyte containing [Co(bpy)3](PF6)2, [Co(pby)3](PF6)3, LiClO4, and 4-tert-butylpyridine (TBP). The ranges of short-circuit current (JSC) from 0.18 to 0.21 (mA/cm(2)), open-circuit voltage (VOC) from 0.24 to 0.55V, and fill factor from 0.34 to 0.39 were obtained for the DSSCs made using the working electrodes. The efficiency of the working electrodes after the addition of TBL was more than doubled. The light scattering and carrier transport properties of these composites promote the performance of dye-sensitized solar cells (DSSCs). Copyright © 2013 Elsevier B.V. All rights reserved.

A Blue Diketopyrrolopyrrole Sensitizer with High Efficiency in Nickel-Oxide-based Dye-Sensitized Solar Cells.

PubMed

Farré, Yoann; Raissi, Mahfoudh; Fihey, Arnaud; Pellegrin, Yann; Blart, Errol; Jacquemin, Denis; Odobel, Fabrice

2017-06-22

We prepared a series of four new diketopyrrolopyrroles (DPPs)-based sensitizers that exhibit high-molar extinction coefficients, extended absorption into the long wavelengths, and well-suited photoredox properties to act as sensitizers in p-type dye-sensitized solar cells (p-DSSCs). These new DPP dyes, composed of a thienyl DPP core, are substituted on one end either by a thiophene carboxylic (Th) or a 4,4'-[(phenyl)aza]dibenzoic acid as anchoring group and, on the other extremity, either by a proton or a naphthalene diimide (NDI) moiety. These new dyes were completely characterized by absorption and emission spectroscopy along with electrochemistry and they were modeled by time-dependent DFT (TD-DFT) quantum chemical calculations. The photovoltaic study in p-DSSC with iodine-based electrolyte reveals that the Th-DPP-NDI dye is particularly efficient (J sc =7.38 mA cm -2 ; V oc =147 mV; FF=0.32; η=0.35 %) and quite active in the low-energy region of the solar spectrum (above 700 nm), where only a few NiO dyes are effective. To illustrate the potential of DPP dyes in photocathodes, we designed a highly efficient tandem DSSC composed of a TiO 2 photoanode sensitized by the dye D35 and a NiO photocathode sensitized by Th-DPP-NDI. This tandem DSSC gives the highest performances ever reported (J sc =6.73 mA cm -2 ; V oc =910 mV; η=4.1 %) and, importantly, the tandem cell outcompetes with the sub-cells. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Investigation of the influence of coadsorbent dye upon the interfacial structure of dye-sensitized solar cells

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

Honda, M., E-mail: honda.mitsunori@jaea.go.jp; Miyano, K.; Yanagida, M.

2014-11-07

The interface between Ru(tcterpy)(NCS){sub 3}TBA{sub 2} [black dye (BD); tcterpy = 4,4{sup ′},4{sup ″}-tricarboxy-2,2{sup ′}:6{sup ′},2{sup ″}-terpyridine, NCS = thiocyanato, TBA = tetrabutylammonium cation] and nanocrystalline TiO{sub 2}, as found in dye-sensitized solar cells, is investigated by soft-X-ray synchrotron radiation and compared with the adsorption structure of cis-Ru(Hdcbpy){sub 2}(NCS){sub 2}TBA{sub 2} (N719; dcbpy = 4,4{sup ′}-dicarboxy-2,2{sup ′}-bipyridine) on TiO{sub 2} to elucidate the relationship between the adsorption mode of BD and the photocurrent with and without coadsorbed indoline dye D131. The depth profile is characterized with X-ray photoelectron spectroscopy and S K-edge X-ray absorption fine structure using synchrotron radiation. Bothmore » datasets indicate that one of the isothiocyanate groups of BD interacts with TiO{sub 2} via its S atom when the dye is adsorbed from a single-component solution. In contrast, the interaction is slightly suppressed when D131 is coadsorbed, indicated by the fact that the presence of D131 changes the adsorption mode of BD. Based upon these results, the number of BD dye molecules interacting with the substrate is shown to decrease by 10% when D131 is coadsorbed, and the dissociation is shown to be related to the short-circuit photocurrent in the 600–800 nm region. The design of a procedure to promote the preferential adsorption of D131 therefore leads to an improvement of the short-circuit current and conversion efficiency.« less

Integrated three-dimensional photonic nanostructures for achieving near-unity solar absorption and superhydrophobicity

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

Kuang, Ping; Lin, Shawn-Yu, E-mail: sylin@rpi.edu; Hsieh, Mei-Li

2015-06-07

In this paper, we proposed and realized 3D photonic nanostructures consisting of ultra-thin graded index antireflective coatings (ARCs) and woodpile photonic crystals. The use of the integrated ARC and photonic crystal structure can achieve broadband, broad-angle near unity solar absorption. The amorphous silicon based photonic nanostructure experimentally shows an average absorption of ∼95% for λ = 400–620 nm over a wide angular acceptance of θ = 0°–60°. Theoretical studies show that a Gallium Arsenide (GaAs) based structure can achieve an average absorption of >95% for λ = 400–870 nm. Furthermore, the use of the slanted SiO{sub 2} nanorod ARC surface layer by glancing angle deposition exhibits Cassie-Baxter statemore » wetting, and superhydrophobic surface is obtained with highest water contact angle θ{sub CB} ∼ 153°. These properties are fundamentally important for achieving maximum solar absorption and surface self-cleaning in thin film solar cell applications.« less

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

Organic nanofibers from squarylium dyes: local morphology, optical, and electrical properties

NASA Astrophysics Data System (ADS)

Balzer, Frank; Schiek, Manuela; Osadnik, Andreas; Lützen, Arne; Rubahn, Horst-Günter

2012-02-01

Environmentally stable, non-toxic squarylium dyes with strong absorption maxima in the red and near infrared spectral region are known for almost fifty years. Despite the fact that their optoelectronic properties distinguish them as promising materials for organics based photovoltaic cells, they have regained attention only very recently. For their application in heterojunction solar cells knowledge of their nanoscopic morphology as well as nanoscopic electrical properties is paramount. In this paper thin films from two different squarylium dyes, from squarylium (SQ) and from hydroxy-squarylium (SQOH) are investigated. The thin films are either solution casted or vacuum sublimed onto substrates such as muscovite mica, which are known to promote self-assembly into oriented, crystalline nanostructures such as nanofibers. Local characterization is performed via (polarized) optical microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), and Kelvin probe force microscopy (KPFM).

The application of sensitizers from red frangipani flowers and star gooseberry leaves in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Almaz Dhafina, Wan; Salleh, Hasiah; Zalani Daud, Muhamad; Ali, Nora’aini

2018-05-01

Nowadays natural based dyes for dye-sensitized solar cells (DSSCs) have been in research field attention due to its advantages over other type of dyes such as low-cost, low-toxicity, completely biodegradable and abundance of resources. Natural dyes can be produced via the simple extraction method of pigments from plant parts such as flower, fruits, leaves, tuber etc. In this feature article, the natural dyes which composed of anthocyanin pigment from red frangipani flowers and chlorophyll from star gooseberry leaves were applied in zinc oxide, (ZnO) based-DSSC. The ZnO photoanode of the DSSCs sample were sensitized in each dye with different duration. It was observed that DSSCs which has chlorophyll pigment as dye had better performance with power conversion efficiency (PCE) of 0.007%.

Engineered porous silicon counter electrodes for high efficiency dye-sensitized solar cells.

PubMed

Erwin, William R; Oakes, Landon; Chatterjee, Shahana; Zarick, Holly F; Pint, Cary L; Bardhan, Rizia

2014-06-25

In this work, we demonstrate for the first time, the use of porous silicon (P-Si) as counter electrodes in dye-sensitized solar cells (DSSCs) with efficiencies (5.38%) comparable to that achieved with platinum counter electrodes (5.80%). To activate the P-Si for triiodide reduction, few layer carbon passivation is utilized to enable electrochemical stability of the silicon surface. Our results suggest porous silicon as a promising sustainable and manufacturable alternative to rare metals for electrochemical solar cells, following appropriate surface modification.

An electro-optical and electron injection study of benzothiazole-based squaraine dyes as efficient dye-sensitized solar cell materials: a first principles study.

PubMed

Al-Fahdan, Najat Saeed; Asiri, Abdullah M; Irfan, Ahmad; Basaif, Salem A; El-Shishtawy, Reda M

2014-12-01

Squaraine dyes have attracted significant attention in many areas of daily life from biomedical imaging to semiconducting materials. Moreover, these dyes are used as photoactive materials in the field of solar cells. In the present study, we investigated the structural, electronic, photophysical, and charge transport properties of six benzothiazole-based squaraine dyes (Cis-SQ1-Cis-SQ3 and Trans-SQ1-Trans-SQ3). The effect of electron donating (-OCH3) and electron withdrawing (-COOH) groups was investigated intensively. Ground state geometry and frequency calculations were performed by applying density functional theory (DFT) at B3LYP/6-31G** level of theory. Absorption spectra were computed in chloroform at the time-dependent DFT/B3LYP/6-31G** level of theory. The driving force of electron injection (ΔG (inject)), relative driving force of electron injection (ΔG r (inject)), electronic coupling constants (|VRP|) and light harvesting efficiency (LHE) of all six compounds were calculated and compared with previously studied sensitizers. The ΔG (inject), ΔG r (inject) and |VRP| of all six compounds revealed that these sensitizers would be efficient dye-sensitized solar cell materials. Cis/Trans-SQ3 exhibited superior LHE as compared to other derivatives. The Cis/Trans geometric effect was studied and discussed with regard to electro-optical and charge transport properties.

Tungsten trioxide nanoplate array supported platinum as a highly efficient counter electrode for dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Song, Dandan; Cui, Peng; Zhao, Xing; Li, Meicheng; Chu, Lihua; Wang, Tianyue; Jiang, Bing

2015-03-01

A tungsten trioxide (WO3) nanoplate array is fabricated directly on the FTO/glass substrate and used as a platinum (Pt) nanoscale supporter for a highly efficient and low Pt-consumption counter electrode (CE) in dye-sensitized solar cells (DSCs). A Pt/WO3 composite structure, with Pt nanoparticles having a diameter of 2-3 nm, increases the electrochemical catalytic activity in catalyzing the reduction of triiodide. Accordingly, the power conversion efficiency is increased from less than 1% for WO3 CE and 8.1% for Pt CE, respectively, to 8.9% for Pt/WO3 CE. Moreover, the use of Pt/WO3 CE can dramatically reduce the consumption of scarce Pt material, with a relatively low Pt-loading of ~2 μg cm-2, while maintaining a much better performance. The excellent performance of Pt/WO3 CE is attributed to the efficient electron injection and transport via WO3 supporters, as well as the nanostructure array morphology of WO3 for deposition of fine Pt nanoparticles. This work provides an approach for developing highly catalytic and low-cost Pt based CEs, which also has implications for the development of Pt/WO3 nanoplate arrays for other applications.A tungsten trioxide (WO3) nanoplate array is fabricated directly on the FTO/glass substrate and used as a platinum (Pt) nanoscale supporter for a highly efficient and low Pt-consumption counter electrode (CE) in dye-sensitized solar cells (DSCs). A Pt/WO3 composite structure, with Pt nanoparticles having a diameter of 2-3 nm, increases the electrochemical catalytic activity in catalyzing the reduction of triiodide. Accordingly, the power conversion efficiency is increased from less than 1% for WO3 CE and 8.1% for Pt CE, respectively, to 8.9% for Pt/WO3 CE. Moreover, the use of Pt/WO3 CE can dramatically reduce the consumption of scarce Pt material, with a relatively low Pt-loading of ~2 μg cm-2, while maintaining a much better performance. The excellent performance of Pt/WO3 CE is attributed to the efficient electron injection and

Development of dye-sensitized solar cells based on naturally extracted dye from the maqui berry (Aristotelia chilensis)

NASA Astrophysics Data System (ADS)

Leyrer, Julio; Hunter, Renato; Rubilar, Monica; Pavez, Boris; Morales, Eduardo; Torres, Simonet

2016-10-01

The mini modules of dye-sensitized solar cells (DSSCs) were investigated for their conversion efficiency using anthocyanin-enriched extracts from maqui berry, which to date has never been tested in a DSSC. Anthocyanins are a group of red, purple, violet and blue water-soluble polyphenolic pigments widely found in berry fruits. Maqui berries are a particularly rich source. The aqueous extract concentrations of maqui fruit were tested at 750 and 1500 mg of anthocyanin/L. The immersion time to produce sensitized TiO2 film was 8 h. According to the experimental results, the conversion efficiency of the DSSC prepared with 750 mg of anthocyanin/L was 0.14%, with an open-circuit voltage (VOC) of 0.43 V, a short-circuit current density (JSC) of 0.38 mA/cm2, and a fill factor (FF) of 0.450. The conversion efficiency attained with 1500 mg of anthocyanin/L was 0.19%, with (VOC) of 0.45 V, (JSC) of 0.44 mA/cm2 and FF of 0.55. Therefore, a higher concentration brought about a higher photosensitized performance. The maqui extracts were successfully dye sensitized over a layer of TiO2 nanoparticles, providing useful information for further studies related to the use of natural pigments as sensitizers for solar cells.

Optical and Photovoltaic Properties of Thieno[3,2-b]thiophene-Based Push-Pull Organic Dyes with Different Anchoring Groups for Dye-Sensitized Solar Cells.

PubMed

Fernandes, Sara S M; Castro, M Cidália R; Pereira, Ana Isabel; Mendes, Adélio; Serpa, Carlos; Pina, João; Justino, Licínia L G; Burrows, Hugh D; Raposo, M Manuela M

2017-12-31

The effect of anchoring groups on the optical and electrochemical properties of triphenylamine-thienothiophenes, and on the photovoltaic performance of DSSCs photosensitized with the prepared dyes, was studied using newly synthesized compounds with cyanoacetic acid or rhodanine-3-acetic acid groups. Precursor aldehydes were synthesized through Suzuki cross-coupling, whereas Knoevenagel condensation of these with 2-cyanoacetic acid or rhodanine-3-acetic acid afforded the final push-pull dyes. A comprehensive photophysical study was performed in solution and in the solid state. The femtosecond time-resolved transient absorption spectra for the synthesized dyes were obtained following photoexcitation in solution and for the dyes adsorbed to TiO 2 mesoporous films. Information on conformation, electronic structure, and electron distribution was obtained by density functional theory (DFT) and time-dependent DFT calculations. Triphenylamine-thienothiophene functionalized with a cyanoacetic acid anchoring group displayed the highest conversion efficiency (3.68%) as the dye sensitizer in nanocrystalline TiO 2 solar cells. Coadsorption studies were performed for this dye with the ruthenium-based N719 dye, and they showed dye power conversion efficiencies enhanced by 20-64%. The best cell performance obtained with the coadsorbed N719 and cyanoacetic dye showed an efficiency of 6.05%.

Optical and Photovoltaic Properties of Thieno[3,2-b]thiophene-Based Push–Pull Organic Dyes with Different Anchoring Groups for Dye-Sensitized Solar Cells

PubMed Central

2017-01-01

The effect of anchoring groups on the optical and electrochemical properties of triphenylamine-thienothiophenes, and on the photovoltaic performance of DSSCs photosensitized with the prepared dyes, was studied using newly synthesized compounds with cyanoacetic acid or rhodanine-3-acetic acid groups. Precursor aldehydes were synthesized through Suzuki cross-coupling, whereas Knoevenagel condensation of these with 2-cyanoacetic acid or rhodanine-3-acetic acid afforded the final push–pull dyes. A comprehensive photophysical study was performed in solution and in the solid state. The femtosecond time-resolved transient absorption spectra for the synthesized dyes were obtained following photoexcitation in solution and for the dyes adsorbed to TiO2 mesoporous films. Information on conformation, electronic structure, and electron distribution was obtained by density functional theory (DFT) and time-dependent DFT calculations. Triphenylamine–thienothiophene functionalized with a cyanoacetic acid anchoring group displayed the highest conversion efficiency (3.68%) as the dye sensitizer in nanocrystalline TiO2 solar cells. Coadsorption studies were performed for this dye with the ruthenium-based N719 dye, and they showed dye power conversion efficiencies enhanced by 20–64%. The best cell performance obtained with the coadsorbed N719 and cyanoacetic dye showed an efficiency of 6.05%. PMID:29302638

Stability issues pertaining large area perovskite and dye-sensitized solar cells and modules

NASA Astrophysics Data System (ADS)

Castro-Hermosa, S.; Yadav, S. K.; Vesce, L.; Guidobaldi, A.; Reale, A.; Di Carlo, A.; Brown, T. M.

2017-01-01

Perovskite and dye-sensitized solar cells are PV technologies which hold promise for PV application. Arguably, the biggest issue facing these technologies is stability. The vast majority of studies have been limited to small area laboratory cells. Moisture, oxygen, UV light, thermal and electrical stresses are leading the degradation causes. There remains a shortage of stability investigations on large area devices, in particular modules. At the module level there exist particular challenges which can be different from those at the small cell level such as encapsulation (not only of the unit cells but of interconnections and contacts), non-uniformity of the layer stacks and unit cells, reverse bias stresses, which are important to investigate for technologies that aim for industrial acceptance. Herein we present a review of stability investigations published in the literature pertaining large area perovskite and dye-sensitized solar devices fabricated both on rigid (glass) and flexible substrates.

Efficient quasisolid dye- and quantum-dot-sensitized solar cells using thiolate/disulfide redox couple and CoS counter electrode.

PubMed

Meng, Ke; Thampi, K Ravindranathan

2014-12-10

For the first time, a quasisolid thiolate/disulfide-based electrolyte was prepared using succinonitrile as a matrix. An optimized configuration of the quasisolid electrolyte contains 5-mercapto-1-methyltetrazole N-tetramethylammonium/disulfide/LiClO4/N-methylbenzimidazole in the molar ratio of 0.8:0.8:0.1:0.1. Dye-sensitized solar cells fabricated using this quasisolid electrolyte, together with N719 dye-sensitized photoelectrode and CoS counter electrode, attained power conversion efficiencies of 4.25% at 1 sun and 6.19% at 0.1 sun illumination intensities. The optimized quasisolid electrolyte, when introduced to quasisolid CdS quantum-dot-sensitized solar cells, exhibited a power conversion efficiency of 0.94%, despite the fact that CdS absorbs only a small fraction of the visible light, unlike dyes. The encouraging results show the potential for the utilization of the quasisolid thiolate/disulfide-based electrolyte in sensitized solar cells.

Charge collection and pore filling in solid-state dye-sensitized solar cells.

PubMed

Snaith, Henry J; Humphry-Baker, Robin; Chen, Peter; Cesar, Ilkay; Zakeeruddin, Shaik M; Grätzel, Michael

2008-10-22

The solar to electrical power conversion efficiency for dye-sensitized solar cells (DSCs) incorporating a solid-state organic hole-transporter can be over 5%. However, this is for devices significantly thinner than the optical depth of the active composites and by comparison to the liquid electrolyte based DSCs, which exhibit efficiencies in excess of 10%, more than doubling of this efficiency is clearly attainable if all the steps in the photovoltaic process can be optimized. Two issues are currently being addressed by the field. The first aims at enhancing the electron diffusion length by either reducing the charge recombination or enhancing the charge transport rates. This should enable a larger fraction of photogenerated charges to be collected. The second, though less actively investigated, aims to improve the physical composite formation, which in this instance is the infiltration of mesoporous TiO(2) with the organic hole-transporter 2,2',7,7'-tetrakis(N,N-di-p-methoxypheny-amine)-9,9'-spirobifluorene (spiro-MeOTAD). Here, we perform a broad experimental study to elucidate the limiting factors to the solar cell performance. We first investigate the charge transport and recombination in the solid-state dye-sensitized solar cell under realistic working conditions via small perturbation photovoltage and photocurrent decay measurements. From these measurements we deduce that the electron diffusion length near short-circuit is as long as 20 µm. However, at applied biases approaching open-circuit potential under realistic solar conditions, the diffusion length becomes comparable with the film thickness, ∼2 µm, illustrating that real losses to open-circuit voltage, fill factor and hence efficiency are occurring due to ineffective charge collection. The long diffusion length near short-circuit, on the other hand, illustrates that another process, separate from ineffective charge collection, is rendering the solar cell less than ideal. We investigate the

Controlling Morphology and Molecular Packing of Alkane Substituted Phthalocyanine Blend Bulk Heterojunction Solar Cells†

PubMed Central

Jurow, Matthew J.; Hageman, Brian A.; Nam, Chang-Yong; Pabon, Cesar; Black, Charles T.

2013-01-01

Systematic changes in the exocyclic substiution of core phthalocyanine platform tune the absorption properties to yield commercially viable dyes that function as the primary light absorbers in organic bulk heterojunction solar cells. Blends of these complementary phthalocyanines absorb a broader portion of the solar spectrum compared to a single dye, thereby increasing solar cell performance. We correlate grazing incidence small angle x-ray scattering structural data with solar cell performance to elucidate the role of nanomorphology of active layers composed of blends of phthalocyanines and a fullerene derivative. A highly reproducible device architecture is used to assure accuracy and is relevant to films for solar windows in urban settings. We demonstrate that the number and structure of the exocyclic motifs dictate phase formation, hierarchical organization, and nanostructure, thus can be employed to tailor active layer morphology to enhance exciton dissociation and charge collection efficiencies in the photovoltaic devices. These studies reveal that disordered films make better solar cells, short alkanes increase the optical density of the active layer, and branched alkanes inhibit unproductive homogeneous molecular alignment. PMID:23589766

Higher Efficiency for Quasi-Solid State Dye Sensitized Solar Cells Under Low Light Irradiance

NASA Astrophysics Data System (ADS)

Desilva, Ajith; Bandara, T. M. W. J.; Fernado, H. D. N. S.; Fernando, P. S. L.; Dissanayake, M. A. K. L.; Jayasundara, W. J. M. J. S. R.; Furlani, M.; Mellander, B.-E.

2014-03-01

Dye-sensitized solar cells (DSSCs), lower cost solar energy conversion devices are alternative green energy source. The liquid based electrolyte DSSCs have higher efficiencies with many practical issues while the quasi-solid-state DSSCs resolve the key problems but efficiencies are relatively low. Polyacrylonitrile (PAN) based gel polymer electrolytes were fabricated as DSSCs by incorporating ethylene carbonate and propylene carbonate plasticizers and tetrapropylammonium iodide salt. A thin layer of electrolyte was sandwiched between the TiO2 anode (sensitized with N719 dye) and the Pt counter electrode. The electrolyte had an ionic conductivity of 2.6 mS/cm at 25 degrees of Celsius. DSSCs incorporating this gel electrolyte revealed Vsc circuit, Jsc, fill factor (FF) and efficiency values of 0.71 V, 11.8 mA, 51 percent and 4.2 percent respectively under 1 sun irradiation. The efficiency of the cell increased with decreasing solar irradiance achieving up to 10 percent efficiency and 80 percent FF at low irradiance values. This work uncovers that quasi-solid state DSSCs can reach efficiencies close to that of liquid electrolytes based cells.

Solvothermal Synthesis of Hierarchical TiO2 Microstructures with High Crystallinity and Superior Light Scattering for High-Performance Dye-Sensitized Solar Cells.

PubMed

Li, Zhao-Qian; Mo, Li-E; Chen, Wang-Chao; Shi, Xiao-Qiang; Wang, Ning; Hu, Lin-Hua; Hayat, Tasawar; Alsaedi, Ahmed; Dai, Song-Yuan

2017-09-20

In this article, hierarchical TiO 2 microstructures (HM-TiO 2 ) were synthesized by a simple solvothermal method adopting tetra-n-butyl titanate as the titanium source in a mixed solvent composed of N,N-dimethylformamide and acetic acid. Due to the high crystallinity and superior light-scattering ability, the resultant HM-TiO 2 are advantageous as photoanodes for dye-sensitized solar cells. When assembled to the entire photovoltaic device with C101 dye as a sensitizer, the pure HM-TiO 2 -based solar cells showed an ultrahigh photovoltage up to 0.853 V. Finally, by employing the as-obtained HM-TiO 2 as the scattering layer and optimizing the architecture of dye-sensitized solar cells, both higher photovoltage and incident photon-to-electron conversion efficiency value were harvested with respect to TiO 2 nanoparticles-based dye-sensitized solar cells, resulting in a high power conversion efficiency of 9.79%. This work provides a promising strategy to develop photoanode materials with outstanding photoelectric conversion performance.

Magnetic field effects in dye-sensitized solar cells controlled by different cell architecture.

PubMed

Klein, M; Pankiewicz, R; Zalas, M; Stampor, W

2016-07-21

The charge recombination and exciton dissociation are generally recognized as the basic electronic processes limiting the efficiency of photovoltaic devices. In this work, we propose a detailed mechanism of photocurrent generation in dye-sensitized solar cells (DSSCs) examined by magnetic field effect (MFE) technique. Here we demonstrate that the magnitude of the MFE on photocurrent in DSSCs can be controlled by the radius and spin coherence time of electron-hole (e-h) pairs which are experimentally modified by the photoanode morphology (TiO2 nanoparticles or nanotubes) and the electronic orbital structure of various dye molecules (ruthenium N719, dinuclear ruthenium B1 and fully organic squaraine SQ2 dyes). The observed MFE is attributed to magnetic-field-induced spin-mixing of (e-h) pairs according to the Δg mechanism.

Magnetic field effects in dye-sensitized solar cells controlled by different cell architecture

NASA Astrophysics Data System (ADS)

Klein, M.; Pankiewicz, R.; Zalas, M.; Stampor, W.

2016-07-01

The charge recombination and exciton dissociation are generally recognized as the basic electronic processes limiting the efficiency of photovoltaic devices. In this work, we propose a detailed mechanism of photocurrent generation in dye-sensitized solar cells (DSSCs) examined by magnetic field effect (MFE) technique. Here we demonstrate that the magnitude of the MFE on photocurrent in DSSCs can be controlled by the radius and spin coherence time of electron-hole (e-h) pairs which are experimentally modified by the photoanode morphology (TiO2 nanoparticles or nanotubes) and the electronic orbital structure of various dye molecules (ruthenium N719, dinuclear ruthenium B1 and fully organic squaraine SQ2 dyes). The observed MFE is attributed to magnetic-field-induced spin-mixing of (e-h) pairs according to the Δg mechanism.

Molecular engineering of sensitizers for dye-sensitized solar cell applications.

PubMed

Giribabu, Lingamallu; Kanaparthi, Ravi Kumar; Velkannan, Veerapandian

2012-06-01

Dye-sensitized solar cells (DSSCs) have attracted considerable attention in recent years as they offer the possibility of low-cost conversion of photovoltaic energy. This account focuses on recent advances in molecular design and technological aspects of sensitizers based on metal complexes, metal-free organics and tetrapyrrolic compounds which include porphyrins, phthalocyanines as well as corroles. Special attention has been paid to the design principles of these dyes, and co-sensitization, an emerging technique to extend the absorption range, is also discussed as a way to improve the performance of the device. This account also focuses on recent advances of efficient ruthenium sensitizers as well as other metal complexes and their applications in DSSCs. Recent developments in the area of metal-free organic and tetrapyrrolic sensitizers are also discussed. Copyright © 2012 The Japan Chemical Journal Forum and Wiley Periodicals, Inc.

Interrelationship between TiO2 nanoparticle size and kind/size of dyes in the mechanism and conversion efficiency of dye sensitized solar cells.

PubMed

Tahay, Pooya; Babapour Gol Afshani, Meisam; Alavi, Ali; Parsa, Zahra; Safari, Nasser

2017-05-10

In order to provide a comprehensive investigation of TiO 2 nanoparticle size in relation with different dye types in DSSCs, three sizes of TiO 2 nanoparticles and two different dye types including a porphyrin dye (T2) and a ruthenium dye (N3) were synthesized. Steady state current-voltage (J-V) characteristics were investigated for the fabricated DSSCs and the results demonstrated that the optimum TiO 2 nanoparticle size changed with the dye type. The obtained J-V data were interpreted by cyclic voltammetry, UV-visible absorption spectroscopy, BET measurement, DFT calculation, IPCE measurement and impedance spectroscopy. The results for the N3 dye show that the surface area of the TiO 2 nanoparticles is a key factor for the N3 cells, which is restricted by TiO 2 pore diameter and surface state traps. In contrast, the density of localized states of the TiO 2 film under the LUMO state of the porphyrin dyes is the dominating factor for the performance of the solar cells, which is restricted by the surface area of the TiO 2 nanoparticles. These obtained results represent a significant advance in the development of porphyrin, ruthenium and even solid electrolyte DSSCs.

Dye sensitized solar cell based on environmental friendly eosin Y dye and Al doped titanium dioxide nano particles

NASA Astrophysics Data System (ADS)

Kulkarni, Swati S.; Bodkhe, Gajanan A.; Shirsat, Sumedh M.; Hussaini, S. S.; Shejwal, N. N.; Shirsat, Mahendra D.

2018-03-01

Present communication deals with the development of cost effective dye sensitized solar cell (DSSC) with eco-friendly materials. Eco-friendly Eosin Y dye was used to sensitize photo anode which was fabricated using undoped and Aluminium doped titanium dioxide (TiO2) nanoparticles. Undoped and Aluminium doped TiO2 nanoparticles were synthesized by simple and cost effective sol-gel method. Aluminium doped and undoped TiO2 nanoparticles were characterized using UV-visible, FT-IR spectroscopy, x-ray Diffraction, and Scanning Electron Micrograph with EDX. The photo-voltaic activity of the cell was studied under light irradiation of 100 milliwatt cm-2. Aluminium doped TiO2 nanoparticle photo electrode exhibits more than 60% increase in cell efficiency as compared to the undoped TiO2 nanoparticle photo electrode.

Dye-Incorporated Polynaphthalenediimide Acceptor for Additive-Free High-Performance All-Polymer Solar Cells.

PubMed

Chen, Dong; Yao, Jia; Chen, Lie; Yin, Jingping; Lv, Ruizhi; Huang, Bin; Liu, Siqi; Zhang, Zhi-Guo; Yang, Chunhe; Chen, Yiwang; Li, Yongfang

2018-04-16

All-polymer solar cells (all-PSCs) can offer unique advantages for applications in flexible devices, and naphthalene diimide (NDI)-based polymer acceptors are the widely used polymer acceptors. However, their power conversion efficiency (PCE) still lags behind that of state-of-the-art polymer solar cells, due to low light absorption, suboptimal energy levels and the strong aggregation of the NDI-based polymer acceptor. Herein, a rhodanine-based dye molecule was introduced into the NDI-based polymer acceptor by simple random copolymerization and showed an improved light absorption coefficient, an up-shifted lowest unoccupied molecular orbital level and reduced crystallization. Consequently, additive-free all-PSCs demonstrated a high PCE of 8.13 %, which is one of the highest performance characteristics reported for all-PSCs to date. These results indicate that incorporating a dye into the n-type polymer gives insight into the precise design of high-performance polymer acceptors for all-PSCs. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microstructure characterization of onion (A.cepa) peels and thin films for dye sensitized solar cells

NASA Astrophysics Data System (ADS)

Abodunrin, T.; Boyo, A.; Usikalu, M.; Obafemi, L.; Oladapo, O.; Kotsedi, L.; Yenus, Z.; Maaza, M.

2017-03-01

A.cepa peels are obtained from mature onion bulbs. Because of the continuous need for energy, alternative avenues for producing energy are gaining importance. The motivation for this work is based on an urgent need to source energy from readily available waste materials like domestic onion peels. Dye sensitized solar cells (DSSCs) fabricated via doctor blade method and high temperature sintering from waste (onion peels) are investigated for their ability to convert solar to electrical energy. The charge carriers were revealed under phytochemical screening. Functional groups of compounds present in A.cepa peel were analyzed with Fourier transform in infrared (FTIR). The influence of different electrolyte sensitizer is observed on the DSSCs under standard air mass conditions of 1.5 AM. The microstructure properties of these A.cepa DSSCs were explored using scanning electron microscope with energy dispersive spectroscopy (SEM/EDS), x-ray diffraction and Fluorecence spectroscopy (XRF). The interfacial boundary between A.cepa dye, TiO2 framework of TiO2 and indium doped tin oxide (ITO) reveals several prominent anatase and rutile peaks. Photoelectric results, revealed dye-sensitized solar cells with a maximum power output of 126 W and incident photon to conversion energy (IPCE) of 0.13%.This work has established that A.cepa peels can be used as a source of micro-energy generation.

Impact of natural photosensitizer extraction solvent upon light absorbance in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Suhaimi, Suriati; Mohamed Siddick, Siti Zubaidah; Ahmad Hambali, Nor Azura Malini; Retnasamy, Vithyacharan; Abdul Wahid, Mohamad Halim; Mohamad Shahimin, Mukhzeer

2017-02-01

Natural pigmentations of Ardisia, Bawang Sabrang, Harum Manis mango, Oxalis Triangularis and Rosella were used to study the general trend in performance of dyes as a photosensitizer in the application of dye-sensitized solar cells (DSSCs) based on optical light absorbance and photoelectrochemical characteristics. From the Ultraviolet-Visible Spectrophotometer with the recorded absorption measurements in the range between 400 nm to 800 nm, the dyes extracted from Rosella and Oxalis Triangularis in water solvent exhibited the conversion efficiency up to 0.68% and 0.67%, respectively. The light absorbance peak for dye extracted from Ardisia, Bawang Sabrang, Oxalis Triangularis and Rosella in water and ethanol solvent resulted in the range between 500 nm to 650 nm, while the Harum Manis mango resulted in the broader spectra in both water and ethanol solvent. The light absorbance spectra of each the dyes shows shifted wavelength spectrum when the extracted dye is adsorbed onto TiO2 film surface that might influenced the absorption of light by TiO2 particle in the visible region. The capabilities of the dyes to absorb light when bonded onto the TiO2 photoanode was found to be significant with the current-voltage conversion of the cell. The results demonstrates just the tip of the vastness of natural dyes' (native to tropical region) feasibility and applicability as a photosensitizer.

Dye-sensitized solar cells using ionic liquids as redox mediator

NASA Astrophysics Data System (ADS)

Denizalti, Serpil; Ali, Abdulrahman Khalaf; Ela, Çağatay; Ekmekci, Mesut; Erten-Ela, Sule

2018-01-01

In this research, the influence of ionic liquid on the conversion efficiency, incident photons to converted electrons (IPCE) and performance of fabricated solar cell was investigated using various ionic liquids. Ionic liquids with different substituents and ions were prepared and used as redox mediators in dye-sensitized solar cells (DSSCs). Ionic liquids were characterized 1H and 13C NMR spectra. We practically investigated the performance of ionic liquid salts were used as the mobile ions and found that the efficiencies of DSSCs were increased up to 40% comparing commercial electrolyte system. The ionic liquid compounds were incorporated in DSSCs to obtain an efficient charge transfer, solving the corrosion problem of platinum layer in counter electrode compared to commercial electrolyte.

Energy-Cascaded Upconversion in an Organic Dye-Sensitized Core/Shell Fluoride Nanocrystal.

PubMed

Chen, Guanying; Damasco, Jossana; Qiu, Hailong; Shao, Wei; Ohulchanskyy, Tymish Y; Valiev, Rashid R; Wu, Xiang; Han, Gang; Wang, Yan; Yang, Chunhui; Ågren, Hans; Prasad, Paras N

2015-11-11

Lanthanide-doped upconversion nanoparticles hold promises for bioimaging, solar cells, and volumetric displays. However, their emission brightness and excitation wavelength range are limited by the weak and narrowband absorption of lanthanide ions. Here, we introduce a concept of multistep cascade energy transfer, from broadly infrared-harvesting organic dyes to sensitizer ions in the shell of an epitaxially designed core/shell inorganic nanostructure, with a sequential nonradiative energy transfer to upconverting ion pairs in the core. We show that this concept, when implemented in a core-shell architecture with suppressed surface-related luminescence quenching, yields multiphoton (three-, four-, and five-photon) upconversion quantum efficiency as high as 19% (upconversion energy conversion efficiency of 9.3%, upconversion quantum yield of 4.8%), which is about ~100 times higher than typically reported efficiency of upconversion at 800 nm in lanthanide-based nanostructures, along with a broad spectral range (over 150 nm) of infrared excitation and a large absorption cross-section of 1.47 × 10(-14) cm(2) per single nanoparticle. These features enable unprecedented three-photon upconversion (visible by naked eye as blue light) of an incoherent infrared light excitation with a power density comparable to that of solar irradiation at the Earth surface, having implications for broad applications of these organic-inorganic core/shell nanostructures with energy-cascaded upconversion.

Highly efficient monolithic dye-sensitized solar cells.

PubMed

Kwon, Jeong; Park, Nam-Gyu; Lee, Jun Young; Ko, Min Jae; Park, Jong Hyeok

2013-03-01

Monolithic dye-sensitized solar cells (M-DSSCs) provide an effective way to reduce the fabrication cost of general DSSCs since they do not require transparent conducting oxide substrates for the counter electrode. However, conventional monolithic devices have low efficiency because of the impediments resulting from counter electrode materials and spacer layers. Here, we demonstrate highly efficient M-DSSCs featuring a highly conductive polymer combined with macroporous polymer spacer layers. With M-DSSCs based on a PEDOT/polymer spacer layer, a power conversion efficiency of 7.73% was achieved, which is, to the best of our knowledge, the highest efficiency for M-DSSCs to date. Further, PEDOT/polymer spacer layers were applied to flexible DSSCs and their cell performance was investigated.

Mineralization of the textile dye acid yellow 42 by solar photoelectro-Fenton in a lab-pilot plant.

PubMed

Espinoza, Carolina; Romero, Julio; Villegas, Loreto; Cornejo-Ponce, Lorena; Salazar, Ricardo

2016-12-05

A complete mineralization of a textile dye widely used in the Chilean textile industry, acid yellow 42 (AY42), was studied. Degradation was carried out in an aqueous solution containing 100mgL(-1) of total organic carbon (TOC) of dye using the advanced solar photoelectro-Fenton (SPEF) process in a lab-scale pilot plant consisting of a filter press cell, which contains a boron doped diamond electrode and an air diffusion cathode (BDD/air-diffusion cell), coupled with a solar photoreactor for treat 8L of wastewater during 270min of electrolysis. The main results obtained during the degradation of the textile dye were that a complete transformation to CO2 depends directly on the applied current density, the concentration of Fe(2+) used as catalyst, and the solar radiation intensity. The elimination of AY42 and its organic intermediates was due to hydroxyl radicals formed at the anode surface from water oxidation and in the bulk from Fenton's reaction between electrogenerated H2O2 and added Fe(2+). The application of solar radiation in the process (SPEF) yield higher current efficiencies and lower energy consumptions than electro-Fenton (EF) and electro-oxidation with electrogenerated H2O2 (E OH2O2) by the additional production of hydroxyl radicals from the photolysis of Fe(III) hydrated species and the photodecomposition of Fe(III) complexes with organic intermediates. Moreover, some products and intermediates formed during mineralization of dye, such as inorganic ions, carboxylic acids and aromatic compounds were determined by photometric and chromatographic methods. An oxidation pathway is proposed for the complete conversion to CO2. Copyright © 2016 Elsevier B.V. All rights reserved.

Preparation of anatase TiO2 nanoparticles using low hydrothermal temperature for dye-sensitized solar cell

NASA Astrophysics Data System (ADS)

Sofyan, N.; Ridhova, A.; Yuwono, A. H.; Udhiarto, A.

2018-03-01

One device being developed as an alternative source of renewable energy by utilizing solar energy source is dye-sensitized solar cells (DSSC). This device works using simple photosynthetic-electrochemical principle in the molecular level. In this device, the inorganic oxide semiconductor of titanium dioxide (TiO2) has a great potential for the absorption of the photon energy from the solar energy source, especially in the form of TiO2 nanoparticle structure. This nanoparticle structure is expected to improve the performance of DSSC because the surface area to weight ratio of this nanostructures is very large. In this study, the synthesis of TiO2 nanoparticle from its precursors has been performed along with the fabrication of the DSSC device. Effort to improve the size of nanocrystalline anatase TiO2 was accomplished by low hydrothermal treatment at various temperatures whereas the crystallinity of the anatase phase in the structure was performed by calcination process. Characterization of the materials was performed using X-ray Diffraction (XRD) and scanning electron microscope (SEM), while the DSSC performance was examined through a high precision current versus voltage (I-V) curve analyzer. The results showed that pure anatase TiO2 nanoparticles could be obtained at low hydrothermal of 100, 125, and 150 °C followed by calcination at 450 °C. The best performance of photocurrent-voltage characteristic was given by TiO2 hydrothermally synthesized at 150 °C with power conversion efficiency (PCE) of 4.40 %, whereas the standard TiO2 nanoparticles has PCE only 4.02 %. This result is very promising in terms low temperature and thus low cost of anatase TiO2 semiconductor preparation for DSSC application.

An investigation on the photoelectrochemical properties of dye-sensitized solar cells based on graphene-TiO2 composite photoanodes

NASA Astrophysics Data System (ADS)

Zhu, Menghua; Li, Xin; Liu, Weiwei; Cui, Ying

2014-09-01

The graphene-TiO2 nanocomposite has been prepared by mixing graphene oxide (GO) and tetra-n-butyl titanate (TBT) followed by the facile hydrothermal process when the reduction of GO to reduced graphene oxide (RGO) and the hydrolysis of TBT to TiO2 happen. Characterization of the graphene-TiO2 nanostructures is investigated in detail by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. A dye-sensitized solar cell (DSSC) based on graphene-TiO2 composite photoelectrode exhibits a high energy conversion efficiency of 4.28%, compared with a DSSC based on pure TiO2 photoelectrode (3.11%), accompanied by an increment in both short-circuit photocurrent density and open-circuit voltage. The significant enhancement in performance of DSSC is investigated through intensity-modulated photovoltage spectroscopy, intensity-modulated photocurrent spectroscopy, and electrochemical impedance spectroscopy. It is found that the incorporation of two-dimensional graphene nanosheets in the TiO2 electrodes is the key factor leading to the improved photogenerated electron transfer ability and reduced charge recombination.

Dye-Sensitized Solar Cells Employing Extracts from Four Cassia Flowers as Natural Sensitizers: Studies on Dye Ingredient Effect on Photovoltaic Performance

NASA Astrophysics Data System (ADS)

Maurya, Ishwar Chandra; Singh, Shalini; Neetu; Gupta, Arun Kumar; Srivastava, Pankaj; Bahadur, Lal

2018-01-01

Natural dyes extracted from four different flowers, namely, Cassia surattensis, Cassia tora, Cassia alata and Cassia occidentalis were used as sensitizers for TiO2-based dye-sensitized solar cells (DSSC). The dye extracts from flowers were obtained by a simple extraction technique and used without any further purification. Optical characteristics of dye extracts were studied. Fourier-transform infrared (FTIR) spectra were used to identify the constituents of extracted dyes. The photovoltaic performance of DSSC employing dye-capped TiO2 photoanodes was measured. The sensitization performance related to anchoring groups present and interaction between dyes with TiO2 surface is demonstrated. An attempt has been made to rationalize the observations by light absorption of the dye extracts and their adsorption on TiO2. The short-circuit current density ( I SC) values ranged from 0.06 mA/cm2 to 0.20 mA/cm2; open circuit voltage ( V OC) from 0.292 V to 0.833 V; fill factor (FF) from 0.7 to 0.9; efficiencies ( η) from 0.013% to 0.15% and incident photon-to-current conversion efficiency from 13% to 20%, were obtained for DSSC using these natural dye extracts. Cassia occidentalis showed the highest current density of 0.20 mA/cm2 and power conversion efficiency of 0.15%, which was due to better interaction between the carbonyl and hydroxyl group of the anthocyanin molecule of C. occidentalis and surface of TiO2 film. The red and blue shift of absorption wavelength of C. surattensis and the blue shift of absorption wavelength of the C. tora, C. alata and C. occidentalis extract in ethanol solution compared to that on TiO2 film has been used for the interpretation of obtained results.

Near Field Enhanced Photocurrent Generation in P-type Dye-Sensitized Solar Cells

PubMed Central

Xu, Xiaobao; Cui, Jin; Han, Junbo; Zhang, Junpei; Zhang, Yibo; Luan, Lin; Alemu, Getachew; Wang, Zhong; Shen, Yan; Xiong, Dehua; Chen, Wei; Wei, Zhanhua; Yang, Shihe; Hu, Bin; Cheng, Yibing; Wang, Mingkui

2014-01-01

Over the past few decades, the field of p-type dye-sensitized solar cell (p-DSSC) devices has undergone tremendous advances, in which Cu-based delafossite nanocrystal is of prime interest. This paper presents an augment of about 87% improvement in photocurrent observed in a particular configuration of organic dye P1 sensitized CuCrO2 delafossite nanocrystal electrode coupled with organic redox shuttle, 1-methy-1H- tetrazole-5-thiolate and its disulfide dimer when Au nanoparticles (NPs, with diameter of about 20 nm) is added into the photocathode, achieving a power convert efficiency of 0.31% (measured under standard AM 1.5 G test conditions). Detailed investigation shows that the local electrical-magnetic field effect, induced by Au NPs among the mesoporous CuCrO2 film, can improve the charge injection efficiency at dye/semiconductor interface, which is responsible for the bulk of the gain in photocurrent. PMID:24492539

Near infrared organic semiconducting materials for bulk heterojunction and dye-sensitized solar cells.

PubMed

Singh, Surya Prakash; Sharma, G D

2014-06-01

Dye sensitized solar cells (DSSCs) and bulk heterojunction (BHJ) solar cells have been the subject of intensive academic interest over the past two decades, and significant commercial effort has been directed towards this area with the vison of developing the next generation of low cost solar cells. Materials development has played a vital role in the dramatic improvement of both DSSC and BHJ solar cell performance in the recent years. Organic conjugated polymers and small molecules that absorb solar light in the visible and near infrared (NIR) regions represent a class of emering materials and show a great potential for the use of different optoelectronic devices such as DSSCs and BHJ solar cells. This account describes the emering class of near infrared (NIR) organic polymers and small molecules having donor and acceptors units, and explores their potential applications in the DSSCs and BHJ solar cells. Copyright © 2014 The Chemical Society of Japan and Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structural, Morphological, and Electron Transport Studies of Annealing Dependent In2O3 Dye-Sensitized Solar Cell

PubMed Central

Mahalingam, S.; Abdullah, H.; Shaari, S.; Muchtar, A.; Asshari, I.

2015-01-01

Indium oxide (In2O3) thin films annealed at various annealing temperatures were prepared by using spin-coating method for dye-sensitized solar cells (DSSCs). The objective of this research is to enhance the photovoltaic conversion efficiency in In2O3 thin films by finding the optimum annealing temperature and also to study the reason for high and low performance in the annealed In2O3 thin films. The structural and morphological characteristics of In2O3 thin films were studied via XRD patterns, atomic force microscopy (AFM), field-emission scanning electron microscopy (FESEM), EDX sampling, and transmission electron microscopy (TEM). The annealing treatment modified the nanostructures of the In2O3 thin films viewed through FESEM images. The In2O3-450°C-based DSSC exhibited better photovoltaic performance than the other annealed thin films of 1.54%. The electron properties were studied by electrochemical impedance spectroscopy (EIS) unit. The In2O3-450°C thin films provide larger diffusion rate, low recombination effect, and longer electron lifetime, thus enhancing the performance of DSSC. PMID:26146652

Tungsten trioxide nanoplate array supported platinum as a highly efficient counter electrode for dye-sensitized solar cells.

PubMed

Song, Dandan; Cui, Peng; Zhao, Xing; Li, Meicheng; Chu, Lihua; Wang, Tianyue; Jiang, Bing

2015-03-19

A tungsten trioxide (WO₃) nanoplate array is fabricated directly on the FTO/glass substrate and used as a platinum (Pt) nanoscale supporter for a highly efficient and low Pt-consumption counter electrode (CE) in dye-sensitized solar cells (DSCs). A Pt/WO₃ composite structure, with Pt nanoparticles having a diameter of 2-3 nm, increases the electrochemical catalytic activity in catalyzing the reduction of triiodide. Accordingly, the power conversion efficiency is increased from less than 1% for WO₃ CE and 8.1% for Pt CE, respectively, to 8.9% for Pt/WO₃ CE. Moreover, the use of Pt/WO₃ CE can dramatically reduce the consumption of scarce Pt material, with a relatively low Pt-loading of ∼2 μg cm(-2), while maintaining a much better performance. The excellent performance of Pt/WO₃ CE is attributed to the efficient electron injection and transport via WO₃ supporters, as well as the nanostructure array morphology of WO₃ for deposition of fine Pt nanoparticles. This work provides an approach for developing highly catalytic and low-cost Pt based CEs, which also has implications for the development of Pt/WO₃ nanoplate arrays for other applications.

Surface modifications of photoanodes in dye sensitized solar cells: enhanced light harvesting and reduced recombination

NASA Astrophysics Data System (ADS)

Saxena, Vibha; Aswal, D. K.

2015-06-01

In a quest to harvest solar power, dye-sensitized solar cells (DSSCs) have potential for low-cost eco-friendly photovoltaic devices. The major processes which govern the efficiency of a DSSC are photoelectron generation, injection of photo-generated electrons to the conduction band (CB) of the mesoporous nanocrystalline semiconductor (nc-SC); transport of CB electrons through nc-SC and subsequent collection of CB electrons at the counter electrode (CE) through the external circuit; and dye regeneration by redox couple or hole transport layer (HTL). Most of these processes occur at various interfaces of the photoanode. In addition, recombination losses of photo-generated electrons with either dye or redox molecules take place at the interfaces. Therefore, one of the key requirements for high efficiency is to improve light harvesting of the photoanode and to reduce the recombination losses at various interfaces. In this direction, surface modification of the photoanode is the simplest method among the various other approaches available in the literature. In this review, we present a comprehensive discussion on surface modification of the photoanode, which has been adopted in the literature for not only enhancing light harvesting but also reducing recombination. Various approaches towards surface modification of the photoanode discussed are (i) fluorine-doped tin oxide (FTO)/nc-SC interface modified via a compact layer of semiconductor material which blocks exposed sites of FTO to electrolyte (or HTL), (ii) nc-SC/dye interface modification either through acid treatment resulting in enhanced dye loading due to a positively charged surface or by depositing insulating/semiconducting blocking layer on the nc-SC surface, which acts as a tunneling barrier for recombination, (iii) nc-SC/dye interface modified by employing co-adsorbents which helps in reducing the dye aggregation and thereby recombination, and (iv) dye/electrolyte (or dye/HTL) interface modification using

Preparation of Carbon Nanotube/TiO2 Mesoporous Hybrid Photoanode with Iron Pyrite (FeS2) Thin Films Counter Electrodes for Dye-Sensitized Solar Cell

PubMed Central

Kilic, Bayram; Turkdogan, Sunay; Astam, Aykut; Ozer, Oguz Can; Asgin, Mansur; Cebeci, Hulya; Urk, Deniz; Mucur, Selin Pravadili

2016-01-01

Multi-walled carbon nanotube (MWCNT)/TiO2 mesoporous networks can be employed as a new alternative photoanode in dye-sensitized solar cells (DSSCs). By using the MWCNT/TiO2 mesoporous as photoanodes in DSSC, we demonstrate that the MWCNT/TiO2 mesoporous photoanode is promising alternative to standard FTO/TiO2 mesoporous based DSSC due to larger specific surface area and high electrochemical activity. We also show that iron pyrite (FeS2) thin films can be used as an efficient counter electrode (CE), an alternative to the conventional high cost Pt based CE. We are able to synthesis FeS2 nanostructures utilizing a very cheap and easy hydrothermal growth route. MWCNT/TiO2 mesoporous based DSSCs with FeS2 CE achieved a high solar conversion efficiency of 7.27% under 100 mW cm−2 (AM 1.5G 1-Sun) simulated solar irradiance which is considerably (slightly) higher than that of A-CNT/TiO2 mesoporous based DSSCs with Pt CE. Outstanding performance of the FeS2 CE makes it a very promising choice among the various CE materials used in the conventional DSSC and it is expected to be used more often to achieve higher photon-to-electron conversion efficiencies. PMID:27243374

Nanographite-TiO2 photoanode for dye sensitized solar cells

NASA Astrophysics Data System (ADS)

Sharma, S. S.; Sharma, Khushboo; Sharma, Vinay

2016-05-01

Nanographite-TiO2 (NG-TiO2) composite was successfully synthesized by the hydrothermal method and its performance as the photoanode for dye-sensitized solar cells (DSSCs) was investigated. Environmental Scanning electron microscope (E-SEM) micrographs show the uniform distribution of TiO2 nanoflowers deposited over nanographite sheets. The average performance characteristics of the assembled cell in terms of short-ciruit current density (JSC), open circuit voltage (VOC), fill factor (FF) and photoelectric conversion efficiency (η) were measured.

Influence of the electron-cation interaction on electron mobility in dye-sensitized ZnO and TiO2 nanocrystals: a study using ultrafast terahertz spectroscopy.

PubMed

Nemec, H; Rochford, J; Taratula, O; Galoppini, E; Kuzel, P; Polívka, T; Yartsev, A; Sundström, V

2010-05-14

Charge transport and recombination in nanostructured semiconductors are poorly understood key processes in dye-sensitized solar cells. We have employed time-resolved spectroscopies in the terahertz and visible spectral regions supplemented with Monte Carlo simulations to obtain unique information on these processes. Our results show that charge transport in the active solar cell material can be very different from that in nonsensitized semiconductors, due to strong electrostatic interaction between injected electrons and dye cations at the surface of the semiconductor nanoparticle. For ZnO, this leads to formation of an electron-cation complex which causes fast charge recombination and dramatically decreases the electron mobility even after the dissociation of the complex. Sensitized TiO2 does not suffer from this problem due to its high permittivity efficiently screening the charges.

Metal oxide-encapsulated dye-sensitized photoanodes for dye-sensitized solar cells

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

Hupp, Joseph T.; Son, Ho-Jin

2016-01-12

Dye-sensitized semiconducting metal oxide films for photoanodes, photoanodes incorporating the films and DSCs incorporating the photoanodes are provided. Also provided are methods for making the dye sensitized semiconducting metal oxide films. The methods of making the films are based on the deposition of an encapsulating layer of a semiconducting metal oxide around the molecular anchoring groups of photosensitizing dye molecules adsorbed to a porous film of the semiconducting metal oxide. The encapsulating layer of semiconducting metal oxide is formed in such a way that it is not coated over the chromophores of the adsorbed dye molecules and, therefore, allows themore » dye molecules to remain electrochemically addressable.« less

Fabrication of solution processed 3D nanostructured CuInGaS₂ thin film solar cells.

PubMed

Chu, Van Ben; Cho, Jin Woo; Park, Se Jin; Hwang, Yun Jeong; Park, Hoo Keun; Do, Young Rag; Min, Byoung Koun

2014-03-28

In this study we demonstrate the fabrication of CuInGaS₂ (CIGS) thin film solar cells with a three-dimensional (3D) nanostructure based on indium tin oxide (ITO) nanorod films and precursor solutions (Cu, In and Ga nitrates in alcohol). To obtain solution processed 3D nanostructured CIGS thin film solar cells, two different precursor solutions were applied to complete gap filling in ITO nanorods and achieve the desirable absorber film thickness. Specifically, a coating of precursor solution without polymer binder material was first applied to fill the gap between ITO nanorods followed by deposition of the second precursor solution in the presence of a binder to generate an absorber film thickness of ∼1.3 μm. A solar cell device with a (Al, Ni)/AZO/i-ZnO/CdS/CIGS/ITO nanorod/glass structure was constructed using the CIGS film, and the highest power conversion efficiency was measured to be ∼6.3% at standard irradiation conditions, which was 22.5% higher than the planar type of CIGS solar cell on ITO substrate fabricated using the same precursor solutions.

Photoelectrochemical characteristics of dye-sensitized solar cells incorporating innovative and inexpensive materials

NASA Astrophysics Data System (ADS)

Harlow, Lisa Jean

The use of energy is going to continue to increase rapidly due to population and economic advances occurring throughout the world. The most widely used energies produce carbon dioxide during their combustion and have finite limits on how much of these resources are available. A strong push to utilizing renewable energy is necessary to keep up with the demand. The only renewable energy that has unlimited supply is solar. Our goal is to find cost-effective alternatives to historically the most extensively used materials in dye-sensitized solar cells. In order to rely on efficiency changes coinciding with the introduction of a new component, a standard baseline of performance is necessary to establish. A reproducible fabrication procedure composed of standard materials was instituted; the efficiency parameters exhibited a less than 10% standard deviation for any set of solar cells. Any modifications to the cell components would be apparent in the change in efficiency. Our cell modifications focused on economical alternatives to the electrolyte, the counter electrode and the chromophore. Solution-based electrolytes were replaced with a non-volatile ionic liquid, 1-methyl-3-propylimidazolium iodide, and then a poly(imidazole-functionalized) silica nanoparticle. Solid-state electrolytes reduce or prevent leakage and could ease manufacturing in large-scale devices. Platinum has been the counter electrode catalyst primarily used with the iodide/triiodide redox couple, but is a rare metal making it rather costly. We reduce platinum loading by introducing a novel counter electrode that employs platinum nanoparticles embedded on a graphene nanoplatelet paper. The highly conductive carbon base also negates the use of the expensive conductive substrate necessary for the platinum catalyst, further reducing cost. We also study the differences in transitioning from ruthenium polypyridyls to iron-based chromophores in dye-sensitized solar cells. Iron introduces low-lying ligand

Zinc-oxide-based nanostructured materials for heterostructure solar cells

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

Bobkov, A. A.; Maximov, A. I.; Moshnikov, V. A., E-mail: vamoshnikov@mail.ru

Results obtained in the deposition of nanostructured zinc-oxide layers by hydrothermal synthesis as the basic method are presented. The possibility of controlling the structure and morphology of the layers is demonstrated. The important role of the procedure employed to form the nucleating layer is noted. The faceted hexagonal nanoprisms obtained are promising for the fabrication of solar cells based on oxide heterostructures, and aluminum-doped zinc-oxide layers with petal morphology, for the deposition of an antireflection layer. The results are compatible and promising for application in flexible electronics.

The Effects of Phosphonic Acids in Dye-Sensitized Solar Cells

NASA Astrophysics Data System (ADS)

James, Keith Edward

Novel methods for the construction of dye-sensitized solar cells (DSSCs) were developed. A thin dense underlayer of TiO2 was applied on fluorine-doped tin oxide (FTO) glass using as a precursor Tyzor AA-105. Subsequently a mesoporous film of P-25 TiO2 was applied by spreading a suspension uniformly over the surface of the underlayer and allowing the plate to slowly dry while resting on a level surface. After sintering at 500° C slides were treated with TCPP as a sensitizing dye and assembled into DSSCs. A novel method was used to seal the cells; strips of ParafilmRTM were used as spacers between the electrodes and to secure the electrodes together. The cells were filled with a redox electrolyte and sealed by dipping into molten paraffin. A series of phosphonic acids and one arsonic acid were employed as coadsorbates in DSSCs. The coadsorbates were found to compete for binding sites, resulting in lower levels of dye adsorption. The resulting loss of photocurrent was not linear with the reduction of dye loading, and in some cases photocurrent and efficiency were higher for cells with lower levels of dye loading. Electrodes were treated with coadsorbates by procedures including pre-adsorption, simultaneous (sim-adsorption), and post-adsorption, using a range of concentrations and treatment times and a variety of solvents. Most cells were tested using an iodide-triiodide based electrolyte (I3I-1) but some cells were tested using electrolytes based on a Co(II)/Co(III) redox couple (CoBpy electrolytes). Phosphonic acid post-adsorbates increased the Voc of cells using CoBpy electrolytes but caused a decrease in the Voc of cells using I3I-1 electrolyte. Phosphonic acids as sim-adsorbates resulted in a significant increase in efficiency and Jsc, and they show promise as a treatment for TCPP DSSCs.

Review on Metallic and Plastic Flexible Dye Sensitized Solar Cell

NASA Astrophysics Data System (ADS)

Yugis, A. R.; Mansa, R. F.; Sipaut, C. S.

2015-04-01

Dye sensitized solar cells (DSSCs) are a promising alternative for the development of a new generation of photovoltaic devices. DSSCs have promoted intense research due to their low cost and eco-friendly advantage over conventional silicon-based crystalline solar cells. In recent years, lightweight flexible types of DSSCs have attracted much intention because of drastic reduction in production cost and more extensive application. The substrate that used as electrode of the DSSCs has a dominant impact on the methods and materials that can be applied to the cell and consequently on the resulting performance of DSSCs. Furthermore, the substrates influence significantly the stability of the device. Although the power conversion efficiency still low compared to traditional glass based DSSCs, flexible DSSCs still have potential to be the most efficient and easily implemented technology.

Photosynthetic solar cell using nanostructured proton exchange membrane for microbial biofilm prevention.

PubMed

Lee, Dong Hyun; Oh, Hwa Jin; Bai, Seoung Jae; Song, Young Seok

2014-06-24

Unwanted biofilm formation has a detrimental effect on bioelectrical energy harvesting in microbial cells. This issue still needs to be solved for higher power and longer durability and could be resolved with the help of nanoengineering in designing and manufacturing. Here, we demonstrate a photosynthetic solar cell (PSC) that contains a nanostructure to prevent the formation of biofilm by micro-organisms. Nanostructures were fabricated using nanoimprint lithography, where a film heater array system was introduced to precisely control the local wall temperature. To understand the heat and mass transfer phenomena behind the manufacturing and energy harvesting processes of PSC, we carried out a numerical simulation and experimental measurements. It revealed that the nanostructures developed on the proton exchange membrane enable PSC to produce enhanced output power due to the retarded microbial attachment on the Nafion membrane. We anticipate that this strategy can provide a pathway where PSC can ensure more renewable, sustainable, and efficient energy harvesting performance.

ZnO/CuO/M (M = Ag, Au) Hierarchical Nanostructure by Successive Photoreduction Process for Solar Hydrogen Generation.

PubMed

Kwon, Jinhyeong; Cho, Hyunmin; Jung, Jinwook; Lee, Habeom; Hong, Sukjoon; Yeo, Junyeob; Han, Seungyong; Ko, Seung Hwan

2018-05-12

To date, solar energy generation devices have been widely studied to meet a clean and sustainable energy source. Among them, water splitting photoelectrochemical cell is regarded as a promising energy generation way for splitting water molecules and generating hydrogen by sunlight. While many nanostructured metal oxides are considered as a candidate, most of them have an improper bandgap structure lowering energy transition efficiency. Herein, we introduce a novel wet-based, successive photoreduction process that can improve charge transfer efficiency by surface plasmon effect for a solar-driven water splitting device. The proposed process enables to fabricate ZnO/CuO/Ag or ZnO/CuO/Au hierarchical nanostructure, having an enhanced electrical, optical, photoelectrochemical property. The fabricated hierarchical nanostructures are demonstrated as a photocathode in the photoelectrochemical cell and characterized by using various analytic tools.

ZnO/CuO/M (M = Ag, Au) Hierarchical Nanostructure by Successive Photoreduction Process for Solar Hydrogen Generation

PubMed Central

Kwon, Jinhyeong; Cho, Hyunmin; Jung, Jinwook; Lee, Habeom; Han, Seungyong

2018-01-01

To date, solar energy generation devices have been widely studied to meet a clean and sustainable energy source. Among them, water splitting photoelectrochemical cell is regarded as a promising energy generation way for splitting water molecules and generating hydrogen by sunlight. While many nanostructured metal oxides are considered as a candidate, most of them have an improper bandgap structure lowering energy transition efficiency. Herein, we introduce a novel wet-based, successive photoreduction process that can improve charge transfer efficiency by surface plasmon effect for a solar-driven water splitting device. The proposed process enables to fabricate ZnO/CuO/Ag or ZnO/CuO/Au hierarchical nanostructure, having an enhanced electrical, optical, photoelectrochemical property. The fabricated hierarchical nanostructures are demonstrated as a photocathode in the photoelectrochemical cell and characterized by using various analytic tools. PMID:29757225

Conversion efficiency versus sensitizer for electrospun TiO2 nanorod electrodes in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Jose, R.; Kumar, A.; Thavasi, V.; Ramakrishna, S.

2008-10-01

The electrochemical and optical properties of three indoline dyes, namely C35H28N2O2 (D131), C37H30N2O3S2 (D102), and C42H35N3O4S3 (D149), were studied and compared with that of the N3 dye. D131 has the largest bandgap and lowest unoccupied molecular orbital (LUMO) energies compared to the other dyes. A size-dependent variation in the absorptivity of the indoline dyes was observed—the absorptivity increased with increase in the molecular size. The dyes were anchored onto TiO2 nanorods. The TiO2 nanorods were obtained by electrospinning a polymeric solution containing titanium isopropoxide and polyvinylpyrrolidone and subsequent sintering of the as-spun composite fibers. Absorption spectral measurements of the dye-anchored TiO2 showed blue shifts in the excitonic transition of the indoline dyes, the magnitude of which increased with decrease in the molecular size. Dye-sensitized solar cells (DSSCs) were fabricated using the indoline dyes, TiO2 nanorods, and iodide/triiodide electrolyte. The D131 dye showed comparable energy conversion efficiency (η) to that of the N3 dye. A systematic change in the short circuit current density (JSC) and η of the indoline DSSCs was observed. The observed variation in JC is most likely originated from the difference in the electronic coupling strengths between the dye and the TiO2.

3D graphene from CO 2 and K as an excellent counter electrode for dye-sensitized solar cells

DOE PAGES

Wei, Wei; Stacchiola, Dario J.; Hu, Yun Hang

2017-07-19

3D graphene, which was synthesized directly from CO 2 via its exothermic reaction with liquid K, exhibited excellent performance as a counter electrode for a dye-sensitized solar cell (DSSC). The DSSC has achieved a high power conversion efficiency of 8.25%, which is 10 times larger than that (0.74%) of a DSSC with a counter electrode of the regular graphene synthesized via chemical exfoliation of graphite. The efficiency is even higher than that (7.73%) of a dye-sensitized solar cell with an expensive standard Pt counter electrode. This work provides a novel approach to use a greenhouse gas for DSSCs.

Electrohydrodynamic-assisted Assembly of Hierarchically Structured, 3D Crumpled Nanostructures for Efficient Solar Conversions

DOE PAGES

Ishihara, Hidetaka; Chen, Yen-Chang; De Marco, Nicholas; ...

2016-12-07

The tantalizing prospect of harnessing the unique properties of graphene crumpled nanostructures continues to fuel tremendous interest in energy storage and harvesting applications. However, the paper ball-like, hard texture, and closed-sphere morphology of current 3D graphitic nanostructure production not only constricts the conductive pathways but also limits the accessible surface area. Here, we report new insights into electrohydrodynamically-generated droplets as colloidal nanoreactors in that the stimuli-responsive nature of reduced graphene oxide can lead to the formation of crumpled nanostructures with a combination of open structures and doubly curved, saddle-shaped edges. In particular, the crumpled nanostructures dynamically adapt to non-spherical, polyhedralmore » shapes under continuous deposition, ultimately assembling into foam-like microstructures with a highly accessible surface area and spatially interconnected transport pathways. The implementation of such crumpled nanostructures as three-dimensional rear contacts for solar conversion applications realize benefits of a high aspect ratio, electrically addressable and energetically favorable interfaces, and substantial enhancement of both short-circuit currents and fill-factors compared to those made of planar graphene counterparts. Further, the 3D crumpled nanostructures may shed lights onto the development of effective electrocatalytic electrodes due to their open structure that simultaneously allows for efficient water flow and hydrogen escape.« less

Electrohydrodynamic-assisted Assembly of Hierarchically Structured, 3D Crumpled Nanostructures for Efficient Solar Conversions.

PubMed

Ishihara, Hidetaka; Chen, Yen-Chang; De Marco, Nicholas; Lin, Oliver; Huang, Chih-Meng; Limsakoune, Vipawee; Chou, Yi-Chia; Yang, Yang; Tung, Vincent

2016-12-07

The tantalizing prospect of harnessing the unique properties of graphene crumpled nanostructures continues to fuel tremendous interest in energy storage and harvesting applications. However, the paper ball-like, hard texture, and closed-sphere morphology of current 3D graphitic nanostructure production not only constricts the conductive pathways but also limits the accessible surface area. Here, we report new insights into electrohydrodynamically-generated droplets as colloidal nanoreactors in that the stimuli-responsive nature of reduced graphene oxide can lead to the formation of crumpled nanostructures with a combination of open structures and doubly curved, saddle-shaped edges. In particular, the crumpled nanostructures dynamically adapt to non-spherical, polyhedral shapes under continuous deposition, ultimately assembling into foam-like microstructures with a highly accessible surface area and spatially interconnected transport pathways. The implementation of such crumpled nanostructures as three-dimensional rear contacts for solar conversion applications realize benefits of a high aspect ratio, electrically addressable and energetically favorable interfaces, and substantial enhancement of both short-circuit currents and fill-factors compared to those made of planar graphene counterparts. Further, the 3D crumpled nanostructures may shed lights onto the development of effective electrocatalytic electrodes due to their open structure that simultaneously allows for efficient water flow and hydrogen escape.

Electrohydrodynamic-assisted Assembly of Hierarchically Structured, 3D Crumpled Nanostructures for Efficient Solar Conversions

PubMed Central

Ishihara, Hidetaka; Chen, Yen-Chang; De Marco, Nicholas; Lin, Oliver; Huang, Chih-Meng; Limsakoune, Vipawee; Chou, Yi-Chia; Yang, Yang; Tung, Vincent

2016-01-01

The tantalizing prospect of harnessing the unique properties of graphene crumpled nanostructures continues to fuel tremendous interest in energy storage and harvesting applications. However, the paper ball-like, hard texture, and closed-sphere morphology of current 3D graphitic nanostructure production not only constricts the conductive pathways but also limits the accessible surface area. Here, we report new insights into electrohydrodynamically-generated droplets as colloidal nanoreactors in that the stimuli-responsive nature of reduced graphene oxide can lead to the formation of crumpled nanostructures with a combination of open structures and doubly curved, saddle-shaped edges. In particular, the crumpled nanostructures dynamically adapt to non-spherical, polyhedral shapes under continuous deposition, ultimately assembling into foam-like microstructures with a highly accessible surface area and spatially interconnected transport pathways. The implementation of such crumpled nanostructures as three-dimensional rear contacts for solar conversion applications realize benefits of a high aspect ratio, electrically addressable and energetically favorable interfaces, and substantial enhancement of both short-circuit currents and fill-factors compared to those made of planar graphene counterparts. Further, the 3D crumpled nanostructures may shed lights onto the development of effective electrocatalytic electrodes due to their open structure that simultaneously allows for efficient water flow and hydrogen escape. PMID:27924857

Highly stable gel electrolytes for dye solar cells based on chemically engineered polymethacrylic hosts.

PubMed

De Gregorio, Gian Luca; Agosta, Rita; Giannuzzi, Roberto; Martina, Francesca; De Marco, Luisa; Manca, Michele; Gigli, Giuseppe

2012-03-25

Four different species of ionically conductive polymers were synthesized and successfully implemented to formulate novel quasi-solid electrolytes for dye solar cells. A power conversion efficiency superior to 85% of the correspondent liquid electrolyte as well as an excellent cell's stability was demonstrated after 500 days of storage.

The factors influencing nonlinear characteristics of the short-circuit current in dye-sensitized solar cells investigated by a numerical model.

PubMed

Shi, Yushuai; Dong, Xiandui

2013-06-24

A numerical model for interpretation of the light-intensity-dependent nonlinear characteristics of the short-circuit current in dye-sensitized solar cells is suggested. The model is based on the continuity equation and includes the influences of the nongeminate recombination between electrons and electron acceptors in the electrolyte and the geminate recombination between electrons and oxidized dye molecules. The influences of the order and rate constant of the nongeminate recombination reaction, the light-absorption coefficient of the dye, the film thickness, the rate constant of geminate recombination, and the regeneration rate constant on the nonlinear characteristics of the short-circuit current are simulated and analyzed. It is proposed that superlinear and sublinear characteristics of the short-circuit current should be attributed to low electron-collection efficiency and low dye-regeneration efficiency, respectively. These results allow a deep understanding of the origin of the nonlinear characteristics of the short-circuit current in solar cells. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Organic-inorganic hybrid nanostructures for solar cell applications

NASA Astrophysics Data System (ADS)

AbdulAlmohsin, Samir M.

The enticing electro-optical properties of nanostructured materials such as carbon nanotubes, graphene, CdS nanocrystals and ZnO nanowrie bring new vigor into the innovation of photovoltaics. The main purpose of this dissertation is to develop novel nano-structured materials for low cost solar cell applications. Fabrication, characterization, and solar cell application of organic-inorganic hybrid structures are the main focus of this research. Polyaniline (PANI)/multi-walled carbon nanotube (MWNT) composite films were synthesized by an electrochemical polymerization of aniline with airbrushed MWNTs on ITO substrates. It was found that the incorporation of MWNTs in PANI effectively increase the film conductivity with a percolation threshold of 5% of nanotubes in the composite. The solar cell performance strongly depends on the conductivity of the composite films, which can be tuned by adjusting nanotube concentration. A higher conductivity resulted in a better cell performance, resulting from an efficient charge collection. This study indicates that PANI/MWNT composite films with optimized conductivity are potentially useful for low-cost hybrid solar cell applications. CdS nanocrystal-sensitized solar cells (NCSSCs) were investigated by using polyaniline (PANI) as a replacement for conventional platinum counter electrode. The growth time of the nanocrystals significantly affects the solar cell performance. At an optimum growth, the NCSSCs exhibit 0.83% of the conversion efficiency in comparison to 0.13% for the identical cells without CdS nanocrystals. Electrochemical impedance spectroscopy showed that the charge transfer in the solar cells with CdS nanocrystals was improved. The enhanced overall energy conversion efficiency by nanocrystals is attributed to improved light absorption and suppressed recombination rate of interfacial charges at the injection, resulting in significantly improved charge transfer and electron lifetime. In addition, the PANI electrodes

Tuning the Electron-Transport and Electron-Accepting Abilities of Dyes through Introduction of Different π-Conjugated Bridges and Acceptors for Dye-Sensitized Solar Cells.

PubMed

Li, Yuanzuo; Sun, Chaofan; Song, Peng; Ma, Fengcai; Yang, Yanhui

2017-02-17

A series of dyes, containing thiophene and thieno[3,2-b]thiophene as π-conjugated bridging units and six kinds of groups as electron acceptors, were designed for dye-sensitized solar cells (DSSCs). The ground- and excited-state properties of the designed dyes were investigated by using density functional theory (DFT) and time-dependent DFT, respectively. Moreover, the parameters affecting the short-circuit current density and open-circuit voltage were calculated to predict the photoelectrical performance of each dye. In addition, the charge difference density was presented through a three-dimensional (3D) real-space analysis method to investigate the electron-injection mechanism in the complexes. Our results show that the longer conjugated bridge would inhibit the intramolecular charge transfer, thereby affecting the photoelectrical properties of DSSCs. Similarly, owing to the lowest chemical hardness, largest electron-accepting ability, dipole moment (μnormal ) and the change in the energy of the TiO 2 conduction band (ΔECB ), the dye with a (E)-3-(4-(benzo[c][1,2,5]thiadiazol-4-yl)phenyl)-2-cyanoacrylic acid (TCA) acceptor group would exhibit the most significant photoelectrical properties among the designed dyes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

SiN{sub x} layers on nanostructured Si solar cells: Effective for optical absorption and carrier collection

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

Cho, Yunae; Kim, Eunah; Gwon, Minji

2015-10-12

We compared nanopatterned Si solar cells with and without SiN{sub x} layers. The SiN{sub x} layer coating significantly improved the internal quantum efficiency of the nanopatterned cells at long wavelengths as well as short wavelengths, whereas the surface passivation helped carrier collection of flat cells mainly at short wavelengths. The surface nanostructured array enhanced the optical absorption and also concentrated incoming light near the surface in broad wavelength range. Resulting high density of the photo-excited carriers near the surface could lead to significant recombination loss and the SiN{sub x} layer played a crucial role in the improved carrier collection ofmore » the nanostructured solar cells.« less

Metal complex-based electron-transfer mediators in dye-sensitized solar cells

DOEpatents

Elliott, C. Michael; Sapp, Shawn A.; Bignozzi, Carlo Alberto; Contado, Cristiano; Caramori, Stefano

2006-03-28

This present invention provides a metal-ligand complex and methods for using and preparing the same. In particular, the metal-ligand complex of the present invention is of the formula: L.sub.a-M-X.sub.b where L, M, X, a, and b are those define herein. The metal-ligand complexes of the present invention are useful in a variety of applications including as electron-transfer mediators in dye-sensitized solar cells and related photoelectrochromic devices.

Hybrid Dye-Sensitized Solar Cells Consisting of Double Titania Layers for Harvesting Light with Wide Range of Wavelengths

NASA Astrophysics Data System (ADS)

Sadamasu, Kengo; Inoue, Takafumi; Ogomi, Yuhei; Pandey, Shyam S.; Hayase, Shuzi

2011-02-01

We report a hybrid dye-sensitized solar cell consisting of double titania layers (top and bottom layers) stained with two dyes. A top layer fabricated on a glass was mechanically pressed with a bottom layer fabricated on a glass cloth. The glass cloth acts as a supporter of a porous titania layer as well as a holder of electrolyte. The incident photon to current efficiency (IPCE) curve had two peaks corresponding to those of the two dyes, which demonstrates that electrons are collected from both the top and bottom layers.

A Triphenylamine-Based Conjugated Polymer with Donor-π-Acceptor Architecture as Organic Sensitizer for Dye-Sensitized Solar Cells.

PubMed

Zhang, Wei; Fang, Zhen; Su, Mingjuan; Saeys, Mark; Liu, Bin

2009-09-17

A conjugated polymer containing an electron donating backbone (triphenylamine) and an electron accepting side chain (cyanoacetic acid) with conjugated thiophene units as the linkers has been synthesized. Dye-sensitized solar cells (DSSCs) are fabricated utilizing this material as the dye sensitizer, resulting a typical power conversion efficiency of 3.39% under AM 1.5 G illumination, which represents the highest efficiency for polymer dye-sensitized DSSCs reported so far. The results show the good promise of conjugated polymers as sensitizers for DSSC applications. Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Iodine/iodide-free dye-sensitized solar cells.

PubMed

Yanagida, Shozo; Yu, Youhai; Manseki, Kazuhiro

2009-11-17

Dye-sensitized solar cells (DSSCs) are built from nanocrystalline anatase TiO(2) with a 101 crystal face (nc-TiO(2)) onto which a dye is absorbed, ruthenium complex sensitizers, fluid I(-)/I(3)(-) redox couples with electrolytes, and a Pt-coated counter electrode. DSSCs have now reached efficiencies as high as 11%, and G24 Innovation (Cardiff, U.K.) is currently manufacturing them for commercial use. These devices offer several distinct advantages. On the basis of the electron lifetime and diffusion coefficient in the nc-TiO(2) layer, DSSCs maintain a diffusion length on the order of several micrometers when the dyed-nc-TiO(2) porous layer is covered by redox electrolytes of lithium and/or imidazolium iodide and their polyiodide salts. The fluid iodide/iodine (I(-)/I(3)(-)) redox electrolytes can infiltrate deep inside the intertwined nc-TiO(2) layers, promoting the mobility of the nc-TiO(2) layers and serving as a hole-transport material of DSSCs. As a result, these materials eventually give a respectable photovoltaic performance. On the other hand, fluid I(-)/I(3)(-) redox shuttles have certain disadvantages: reduced performance control and long-term stability and incompatibility with some metallic component materials. The I(-)/I(3)(-) redox shuttle shows a significant loss in short circuit current density and a slight loss in open circuit voltage, particularly in highly viscous electrolyte-based DSSC systems. Iodine can also act as an oxidizing agent, corroding metals, such as the grid metal Ag and the Pt mediator on the cathode, especially in the presence of water and oxygen. In addition, the electrolytes (I(-)/I(3)(-)) can absorb visible light (lambda = approximately 430 nm), leading to photocurrent loss in the DSSC. Therefore, the introduction of iodide/iodine-free electrolytes or hole-transport materials (HTMs) could lead to cost-effective alternatives to TiO(2) DSSCs. In this Account, we discuss the iodide/iodine-free redox couple as a substitute for the

Optimizing TiO2 nanotube top geometry for use in dye-sensitized solar cells.

PubMed

Mir, Nooshin; Lee, Kiyoung; Paramasivam, Indhumati; Schmuki, Patrik

2012-09-17

Recombination dynamics: For TiO(2) nanotube-based dye-sensitized solar cells, the efficiency can be drastically enhanced by a synergetic effect that occurs when using nanowire-ended nanotubes in combination with an adequate nanoparticle decoration (see figure). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lessons learned: from dye-sensitized solar cells to all-solid-state hybrid devices.

PubMed

Docampo, Pablo; Guldin, Stefan; Leijtens, Tomas; Noel, Nakita K; Steiner, Ullrich; Snaith, Henry J

2014-06-25

The field of solution-processed photovoltaic cells is currently in its second spring. The dye-sensitized solar cell is a widely studied and longstanding candidate for future energy generation. Recently, inorganic absorber-based devices have reached new record efficiencies, with the benefits of all-solid-state devices. In this rapidly changing environment, this review sheds light on recent developments in all-solid-state solar cells in terms of electrode architecture, alternative sensitizers, and hole-transporting materials. These concepts are of general applicability to many next-generation device platforms. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photovoltaic Performance of a Nanowire/Quantum Dot Hybrid Nanostructure Array Solar Cell.

PubMed

Wu, Yao; Yan, Xin; Zhang, Xia; Ren, Xiaomin

2018-02-23

An innovative solar cell based on a nanowire/quantum dot hybrid nanostructure array is designed and analyzed. By growing multilayer InAs quantum dots on the sidewalls of GaAs nanowires, not only the absorption spectrum of GaAs nanowires is extended by quantum dots but also the light absorption of quantum dots is dramatically enhanced due to the light-trapping effect of the nanowire array. By incorporating five layers of InAs quantum dots into a 500-nm high-GaAs nanowire array, the power conversion efficiency enhancement induced by the quantum dots is six times higher than the power conversion efficiency enhancement in thin-film solar cells which contain the same amount of quantum dots, indicating that the nanowire array structure can benefit the photovoltaic performance of quantum dot solar cells.

Photovoltaic Performance of a Nanowire/Quantum Dot Hybrid Nanostructure Array Solar Cell

NASA Astrophysics Data System (ADS)

Wu, Yao; Yan, Xin; Zhang, Xia; Ren, Xiaomin

2018-02-01

An innovative solar cell based on a nanowire/quantum dot hybrid nanostructure array is designed and analyzed. By growing multilayer InAs quantum dots on the sidewalls of GaAs nanowires, not only the absorption spectrum of GaAs nanowires is extended by quantum dots but also the light absorption of quantum dots is dramatically enhanced due to the light-trapping effect of the nanowire array. By incorporating five layers of InAs quantum dots into a 500-nm high-GaAs nanowire array, the power conversion efficiency enhancement induced by the quantum dots is six times higher than the power conversion efficiency enhancement in thin-film solar cells which contain the same amount of quantum dots, indicating that the nanowire array structure can benefit the photovoltaic performance of quantum dot solar cells.

The influence of anatase-rutile mixed phase and ZnO blocking layer on dye-sensitized solar cells based on TiO2nanofiberphotoanodes

PubMed Central

2013-01-01

High performance is expected in dye-sensitized solar cells (DSSCs) that utilize one-dimensional (1-D) TiO2 nanostructures owing to the effective electron transport. However, due to the low dye adsorption, mainly because of their smooth surfaces, 1-D TiO2 DSSCs show relatively lower efficiencies than nanoparticle-based ones. Herein, we demonstrate a very simple approach using thick TiO2 electrospun nanofiber films as photoanodes to obtain high conversion efficiency. To improve the performance of the DSCCs, anatase-rutile mixed-phase TiO2 nanofibers are achieved by increasing sintering temperature above 500°C, and very thin ZnO films are deposited by atomic layer deposition (ALD) method as blocking layers. With approximately 40-μm-thick mixed-phase (approximately 15.6 wt.% rutile) TiO2 nanofiber as photoanode and 15-nm-thick compact ZnO film as a blocking layer in DSSC, the photoelectric conversion efficiency and short-circuit current are measured as 8.01% and 17.3 mA cm−2, respectively. Intensity-modulated photocurrent spectroscopy and intensity-modulated photovoltage spectroscopy measurements reveal that extremely large electron diffusion length is the key point to support the usage of thick TiO2 nanofibers as photoanodes with very thin ZnO blocking layers to obtain high photocurrents and high conversion efficiencies. PMID:23286741

Enhancement of Energy Conversion Efficiency for Dye Sensitized Solar Cell Using Zinc Oxide Photoanode

NASA Astrophysics Data System (ADS)

Jamalullail, N.; Smohamad, I.; Nnorizan, M.; Mahmed, N.

2018-06-01

Dye sensitized solar cell (DSSC) is a third generation solar cell that is well known for its low cost, simple fabrication process and promised reasonable energy conversion efficiency. Basic structure of DSSC is composed of photoanode, dye sensitizer, electrolyte that is sandwiched together in between two transparent conductive oxide (TCO) glasses. Each of the components in the DSSC contributes important role that affect the energy conversion efficiency. In this research, the commonly used titanium dioxide (TiO2) photoanode has previously reported to have high recombination rate and low electron mobility which caused efficiency loss had been compared with the zinc oxide (ZnO) photoanode with high electron mobility (155 cm2V-1s-1). Both of these photoanodes had been deposited through doctor blade technique. The electrical performance of the laboratory based DSSCs were tested using solar cell simulator and demonstrated that ZnO is a better photoanode compared to TiO2 with the energy conversion efficiency of 0.34% and 0.29% respectively. Nanorods shape morphology was observed in ZnO photoanode with average particle size of 41.60 nm and average crystallite size of 19.13 nm. This research proved that the energy conversion efficiency of conventional TiO2 based photoanode can be improved using ZnO material.

Optimization studies of bio-hydrogen production in a coupled microbial electrolysis-dye sensitized solar cell system.

PubMed

Ajayi, Folusho Francis; Kim, Kyoung-Yeol; Chae, Kyu-Jung; Choi, Mi-Jin; Chang, In Seop; Kim, In S

2010-03-01

Bio-hydrogen production in light-assisted microbial electrolysis cell (MEC) with a dye sensitized solar cell (DSSC) was optimized by connecting multiple MECs to a single dye (N719) sensitized solar cell (V(OC) approx. 0.7 V). Hydrogen production occurred simultaneously in all the connected MECs when the solar cell was irradiated with light. The amount of hydrogen produced in each MEC depends on the activity of the microbial catalyst on their anode. Substrate (acetate) to hydrogen conversion efficiencies ranging from 42% to 65% were obtained from the reactors during the experiment. A moderate light intensity of 430 W m(-2) was sufficient for hydrogen production in the coupled MEC-DSSC. A higher light intensity of 915 W m(-2), as well as an increase in substrate concentration, did not show any improvement in the current density due to limitation caused by the rate of microbial oxidation on the anode. A significant reduction in the surface area of the connected DSSC only showed a slight effect on current density in the coupled MEC-DSSC system when irradiated with light.

A Novel of Buton Asphalt and Methylene Blue as Dye-Sensitized Solar Cell using TiO2/Ti Nanotubes Electrode

NASA Astrophysics Data System (ADS)

Nurhidayani; Muzakkar, M. Z.; Maulidiyah; Wibowo, D.; Nurdin, M.

2017-11-01

A study of TiO2/Ti nanotubes arrays (NTAs) based on Dye-Sensitized Solar Cell (DSSC) used Asphalt Buton (Asbuton) extract and methylene blue (MB) as a photosensitizer dye has been conducted. The aim of this research is that the Asbuton extract and Methylene Blue (MB) performance as a dye on DSSC solar cells is able to obtain the voltage-currents produced by visible light irradiation. Electrode TiO2/Ti NTAs have been successfully synthesized by anodizing methods, then characterized by using XRD showed that the anatase crystals formed. Subsequently, the morphology showed that the nanotubes formed which has coated by Asbuton extract. The DSSC system was formed by a sandwich structure and tested by using Multimeter Digital with Potentiostat instrument. The characteristics of current (I) and potential (V) versus time indicated that the Asbuton was obtained in a high-performance in 30s of 14,000µV 0.844µA, meanwhile MB dyes were 8,000µV0.573µA. Based on this research, the Asbuton extract from Buton Island-Southeast Sulawesi-Indonesia was potential for natural dyes in DSSC system.

Dispelling clichés at the nanoscale: the true effect of polymer electrolytes on the performance of dye-sensitized solar cells.

PubMed

Bella, Federico; Sacco, Adriano; Massaglia, Giulia; Chiodoni, Angelica; Pirri, Candido Fabrizio; Quaglio, Marzia

2015-07-28

In the field of dye-sensitized solar cells, polymer electrolytes are among the most studied materials due to their ability to ensure both high efficiency and stability, the latter being a critical point of these devices. Hundreds of polymeric matrices have been proposed over the years, and their functionalization with several groups, the variation of their molecular weight and the tuning of the crosslinking degree have been investigated. However, the true effect that polymeric matrices have on the cell parameters has often been addressed superficially, and hundreds of papers justify the obtained results with a simple bibliographic reference to other systems (sometimes completely different). This work proposes a system of nanoscale growth and crosslinking of a polymer electrolyte inside a nanostructured photoanode. Electrochemical and photovoltaic parameters are carefully monitored as a function of thickness and degree of penetration of the electrolyte. The results derived from this study refute many clichés generally accepted and taken for granted in many literature articles, and – for the first time – a compromise between the amount of polymer, cell efficiency and stability is achieved.

Aqueous dye-sensitized solar cell electrolytes based on the ferricyanide-ferrocyanide redox couple.

PubMed

Daeneke, Torben; Uemura, Yu; Duffy, Noel W; Mozer, Attila J; Koumura, Nagatoshi; Bach, Udo; Spiccia, Leone

2012-03-02

Solar energy conversion efficiencies of over 4% have been achieved in DSCs constructed with aqueous electrolytes based on the ferricyanide-ferrocyanide redox couple, thereby avoiding the use of expensive, flammable and toxic solvents. This paradigm shift was made possible by the use of a hydrophobic organic carbazole dye. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

TiO2 film decorated with highly dispersed polyoxometalate nanoparticles synthesized by micelle directed method for the efficiency enhancement of dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

He, Lifei; Chen, Li; Zhao, Yue; Chen, Weilin; Shan, Chunhui; Su, Zhongmin; Wang, Enbo

2016-10-01

In this work, two kinds of polyoxometalate (POM) nanoparticles with controlled shapes and structures were synthesized by micelle directed method and then composited with TiO2 via calcination to remove the surfactants owing to the excellent electronic storage and transmission ability of POM, finally obtaining two kinds of TiO2 composites with highly dispersed and small-sized POM nanoparticles (∼1 nm). The TiO2 composites were then induced into the photoanodes of dye-sensitized (N719) solar cells (DSSCs). The separation of electron-holes becomes more favorable due to the nanostructure and high dispersion of POM which provide more active sites than pure POM tending to agglomeration. The TiO2 composite photoanodes finally yielded the power conversion efficiency (PCE) of 8.4% and 8.2%, respectively, which were 42% and 39% higher than the pristine TiO2 based anodes. In addition, the mechanisms of POM in DSSC are proposed.

Universal Features of Electron Dynamics in Solar Cells with TiO2 Contact: From Dye Solar Cells to Perovskite Solar Cells.

PubMed

Todinova, Anna; Idígoras, Jesús; Salado, Manuel; Kazim, Samrana; Anta, Juan A

2015-10-01

The electron dynamics of solar cells with mesoporous TiO2 contact is studied by electrochemical small-perturbation techniques. The study involved dye solar cells (DSC), solid-state perovskite solar cells (SSPSC), and devices where the perovskite acts as sensitizer in a liquid-junction device. Using a transport-recombination continuity equation we found that mid-frequency time constants are proper lifetimes that determine the current-voltage curve. This is not the case for the SSPSC, where a lifetime of ∼1 μs, 1 order of magnitude longer, is required to reproduce the current-voltage curve. This mismatch is attributed to the dielectric response on the mid-frequency component. Correcting for this effect, lifetimes lie on a common exponential trend with respect to open-circuit voltage. Electron transport times share a common trend line too. This universal behavior of lifetimes and transport times suggests that the main difference between the cells is the power to populate the mesoporous TiO2 contact with electrons.

Dye-sensitized solar cell employing zinc oxide aggregates grown in the presence of lithium

DOEpatents

Zhang, Qifeng; Cao, Guozhong

2013-10-15

Provided are a novel ZnO dye-sensitized solar cell and method of fabricating the same. In one embodiment, deliberately added lithium ions are used to mediate the growth of ZnO aggregates. The use of lithium provides ZnO aggregates that have advantageous microstructure, morphology, crystallinity, and operational characteristics. Employing lithium during aggregate synthesis results in a polydisperse collection of ZnO aggregates favorable for porosity and light scattering. The resulting nanocrystallites forming the aggregates have improved crystallinity and more favorable facets for dye molecule absorption. The lithium synthesis improves the surface stability of ZnO in acidic dyes. The procedures developed and disclosed herein also help ensure the formation of an aggregate film that has a high homogeneity of thickness, a high packing density, a high specific surface area, and good electrical contact between the film and the fluorine-doped tin oxide electrode and among the aggregate particles.

Long vertically aligned titania nanotubes on transparent conducting oxide for highly efficient solar cells.

PubMed

Varghese, Oomman K; Paulose, Maggie; Grimes, Craig A

2009-09-01

Dye-sensitized solar cells consist of a random network of titania nanoparticles that serve both as a high-surface-area support for dye molecules and as an electron-transporting medium. Despite achieving high power conversion efficiencies, their performance is limited by electron trapping in the nanoparticle film. Electron diffusion lengths can be increased by transporting charge through highly ordered nanostructures such as titania nanotube arrays. Although titania nanotube array films have been shown to enhance the efficiencies of both charge collection and light harvesting, it has not been possible to grow them on transparent conducting oxide glass with the lengths needed for high-efficiency device applications (tens of micrometres). Here, we report the fabrication of transparent titania nanotube array films on transparent conducting oxide glass with lengths between 0.3 and 33.0 microm using a novel electrochemistry approach. Dye-sensitized solar cells containing these arrays yielded a power conversion efficiency of 6.9%. The incident photon-to-current conversion efficiency ranged from 70 to 80% for wavelengths between 450 and 650 nm.

Dye-sensitized solar cell with energy storage function through PVDF/ZnO nanocomposite counter electrode.

PubMed

Zhang, Xi; Huang, Xuezhen; Li, Chensha; Jiang, Hongrui

2013-08-14

Dye-sensitized solar cells with an energy storage function are demonstrated by modifying its counter electrode with a poly (vinylidene fluoride)/ZnO nanowire array composite. This simplex device could still function as an ordinary solar cell with a steady photocurrent output even after being fully charged. An energy storage density of 2.14 C g(-1) is achieved, while simultaneously a 3.70% photo-to-electric conversion efficiency is maintained. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Transition Metal Polypyridine Complexes: Studies of Mediation in Dye-Sensitized Solar Cells and Charge Separation

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

Elliott, C. Michael; Prieto, Amy L.

2017-02-08

The Elliott group has long been supported by DOE for studies of cobalt(II/III) trisbypiridine (DTB) mediator complexes in dye sensitized solar cells. Previous work demonstrated that Co(II/III) chemistry is sensitive to the environment, showing unprecedented electrode-surface and electrolyte dependant voltammetry. In electrolytes that have large lipophilic cations, voltammetry of the [Co(DTB) 3] 2+/3+ couple is nearly Nernstian in appearance on nominally oxide-free metal surfaces. In contrast, on semiconductor electrodes in electrolytes with small, hard cations such as Li +, the electron transfer rates are so slow that it is difficult to measure any Faradaic current even at overpotentials of ±1more » V. These studies are of direct relevance to the operation of cobalt-based mediators in solar cells. The research has also shown that these mediators are compatible with copper phenantroline based dyes, in contrast to I - due to the insolubility of CuI.« less

Electrospinning: A versatile technique for making of 1D growth of nanostructured nanofibers and its applications: An experimental approach

NASA Astrophysics Data System (ADS)

Patil, Jyoti V.; Mali, Sawanta S.; Kamble, Archana S.; Hong, Chang K.; Kim, Jin H.; Patil, Pramod S.

2017-11-01

One dimensional (1D) metal oxide nanostructures (1D-MONS) play a key role in the development of functional devices including energy conversion, energy storage and environmental devices. They are also used for some important biomedical products like wound dressings, filter media, drug delivery and tissue engineering. The electrospinning (ES) is the versatile technique for making of 1D growth of nanostructured nanofibers, an experimental approach and its applications. The present review is focused on the 1D growth of nanostructured nanofibers in different applications like dye sensitized solar cells, perovskite solar cells, fuel cells, lithium ion batteries, redox flow batteries, supercapacitor, photocatalytic, and gas sensors based on ZnO, TiO2, MnO2, WO3, V2O5, NiO, SnO2, Fe2O3 etc. metal oxides, their composites and carbon. This review article presents an introduction to various types of ES techniques and their technical details. Also, the advantages and disadvantages of each ES technique are summarized. The various technical details such as preparative parameters, post-deposition methods, applied electric field, solution feed rate and a distance between a tip to the collector are the key factors in order to obtain exotic 1D nanostructured materials. Also, the lucid literature survey on the growth of nanostructures of various metal oxides and application in different fields are covered in this review. Further, the future perspectives has also been discussed.

Investigation of advanced nanostructured multijunction photoanodes for enhanced solar hydrogen generation via water splitting

NASA Astrophysics Data System (ADS)

Ishihara, Hidetaka

density was observed for the nano-capped titania nanotubes due to the enhanced charge transfer process. Similarly, another metal oxide semiconductor was investigated tungsten trioxide (WO3), which has a much higher absorption capability (12%) in the solar spectrum. The WO3 porous nanostructures suffered from surface corrosion resulting in a large reduction in the photocurrent density as a function of time in the alkaline electrolytes. However, with a protective coating of Indium Tin Oxide (100 nm), the surface corrosion of WO3 porous nanostructures was reduced. A large increase in the photocurrent density of as much as 340% was observed after the ITO was applied to the WO3 porous nanostructures

Design of Far-Red Sensitizing Squaraine Dyes Aiming Towards the Fine Tuning of Dye Molecular Structure.

PubMed

Morimoto, Takuya; Fujikawa, Naotaka; Ogomi, Yuhei; Pandey, Shyam S; Ma, Tingli; Hayase, Shuzi

2016-04-01

Model squaraine dyes having sharp and narrow absorptions mainly in the far-red wavelength region has been logically designed, synthesized and used for their application as sensitizer in the dyesensitized solar cells (DSSC). In order to have fine control on energetics, dyes having same mother core and alkyl chain length varying only in molecular symmetry and position of substituent were designed. It has been found that even keeping all other structural factor constant, only positional variation of substituent leads to not only in the variation of energetics by 0.1 eV but affects the photovoltaic characteristics also. Optimum concentration of dye de-aggregating agent was found to be 100 times with respect to the sensitizing dye concentration. Amongst dyes utilized in this work best performance was obtained for unsymmetrical dye SQ-40 giving a photoconversion efficiency of 4.01% under simulated solar irradiation at global AM 1.5.

Luminescent Spectral Conversion to Improve the Performance of Dye-Sensitized Solar Cells.

PubMed

Hosseini, Zahra; Taghavinia, Nima; Wei-Guang Diau, Eric

2017-12-06

Relative to the broadband solar spectrum, a narrow range of spectral absorption of photovoltaic (PV) devices is considered an important determinant that the efficiency of light harvesting of these devices is less than unity. Having the narrowest spectral response to solar radiation among all PV devices, dye-sensitized solar cells (DSSCs) suffer severely from this loss. Luminescent spectral conversion provides a mechanism to manipulate and to adapt the incident solar spectrum by converting, through photoluminescence, the energies of solar photons into those that are more effectively captured by a PV device. This mechanism is particularly helpful for DSSCs because there is much flexibility in both the choice of the light-harvesting materials and the architecture of the DSSC. Here we review and discuss recent advances in the field of luminescent spectral conversion for DSSCs. The focus is on the architectural design of DSSCs, and the complications, advantages and new functionalities offered by each of their configurations are discussed. The loss mechanisms are examined and important parameters governing the spectral conversion mechanism of a DSSC are introduced. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Polymer based plasmonic elements with dye molecules

NASA Astrophysics Data System (ADS)

Zhang, Douguo; Wang, Xiangxian; Chen, Yikai; Han, Lu; Wang, Pei; Ming, Hai

2012-11-01

Recently, dielectric loaded surface plasmons (SPs) elements are inducing highly interesting in the field of nanooptics, which are composed of dielectric nanostructures fabricated on a metallic thin film. This configuration will provide a route to novel integrated micro-optical devices and components combining photonics and electronics on the same chip. The advantages are easy fabrication, easy integration, and also the potential to realizing active plasmonic devices. In this talk, we will present our recent work in this field. Polymer (PMMA) nano-structures are fabricated on a silver film by the electron beam lithography (EBL) and laser interference lithography. These nano-structures are used to manipulate the behaviors of the SPs, such as converging, diverging, and guiding the propagation of SPs in subwavelength scale. Except for the pure PMMA nano-structures, dye materials (Rhodamine B, RhB) doped PMMA structures are also fabricated on the silver film. The RhB molecules will work as the active medium to excite the SPs or compensation the loss of SPs wave. The dye doped PMMA nanostructure provides a choice to realize active plasmonic elements, such as SPs Bragg gratings. On the other hand, the interaction between the fluorescence molecules and SPs will give rise to some new optical phenomena, such as directional fluorescence emission, anisotropic fluorescence emission. These polymer based plasmonic structures are investigated with a home-built leakage radiation microscopy (LRM).

Ultra-high aspect ratio titania nanoflakes for dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Lee, Yang-Yao; El-Shall, Hassan

2017-12-01

Micron sized titania flakes with thickness about 40 nm were used in the titania pastes to assemble dye-sensitized solar cells (DSSCs). Using the same deposition method, better particle dispersion of titania flakes resulted in well bonded and integral films comparing to cracking of Degussa P25 nanoparticle films during the evaporation and sintering processes. There are two features of titania flakes which leads to improved conversion efficiency of DSSC: (1) Higher and stronger adsorption of N-719 dyes due to high specific surface area (2) Stronger light scattering of visible light spectrum because of micron scale wide in two dimensions of the flakes. The thickness of the conducting TiO2 was critical to the IV characteristics of DSSC such as the short-circuit current density (Isc) and open-circuit voltage (Voc). Under the same thickness basis, calcined titania flakes provided 5 times higher efficiency than the photoelectrodes consisted of Degussa P25 nanoparticles (7.4% vs. 1.2%).

Solar physical vapor deposition preparation and microstructural characterization of TiO2 based nanophases for dye-sensitized solar cell applications.

PubMed

Negrea, Denis; Ducu, Catalin; Moga, Sorin; Malinovschi, Viorel; Monty, Claude J A; Vasile, Bogdan; Dorobantu, Dorel; Enachescu, Marian

2012-11-01

Titanium dioxide exists in three crystalline phases: anatase, rutile and brookite. Although rutile is thermodynamically more stable, anatase is considered as the most favorable phase for photocatalysis and solar energy conversion. Recent studies have shown a significant improvement of light harvesting and overall solar conversion efficiency of anatase nanoparticles in dye-sensitized solar cells (DSSCs) when using a mixture of anatase and rutile phases (10-15% rutile). TiO2 nanopowders have been prepared by a solar physical vapor deposition process (SPVD). This method has been developed in Odeillo-Font Romeu France using "heliotron" solar reactors working under concentrated sunlight in 2 kW solar furnaces. By controlling reactor's atmosphere type (air/argon) and gas pressure, several types of anatase/rutile nanophases have been obtained with slightly different microstructural properties and morphological characteristics. X-ray diffraction analyses (XRD) were performed on precursor and on the SPVD obtained nanopowders. Information concerning their phase composition and coherence diffraction domain (crystallites size and strain) was obtained. Nanopowders morphology has been studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

Quantum-dot-sensitized solar cells.

PubMed

Rühle, Sven; Shalom, Menny; Zaban, Arie

2010-08-02

Quantum-dot-sensitized solar cells (QDSCs) are a promising low-cost alternative to existing photovoltaic technologies such as crystalline silicon and thin inorganic films. The absorption spectrum of quantum dots (QDs) can be tailored by controlling their size, and QDs can be produced by low-cost methods. Nanostructures such as mesoporous films, nanorods, nanowires, nanotubes and nanosheets with high microscopic surface area, redox electrolytes and solid-state hole conductors are borrowed from standard dye-sensitized solar cells (DSCs) to fabricate electron conductor/QD monolayer/hole conductor junctions with high optical absorbance. Herein we focus on recent developments in the field of mono- and polydisperse QDSCs. Stability issues are adressed, coating methods are presented, performance is reviewed and special emphasis is given to the importance of energy-level alignment to increase the light to electric power conversion efficiency.

Recent Progress in Metal-Organic Frameworks and Their Derived Nanostructures for Energy and Environmental Applications.

PubMed

Xie, Zhiqiang; Xu, Wangwang; Cui, Xiaodan; Wang, Ying

2017-04-22

Metal-organic frameworks (MOFs), as a very promising category of porous materials, have attracted increasing interest from research communities due to their extremely high surface areas, diverse nanostructures, and unique properties. In recent years, there is a growing body of evidence to indicate that MOFs can function as ideal templates to prepare various nanostructured materials for energy and environmental cleaning applications. Recent progress in the design and synthesis of MOFs and MOF-derived nanomaterials for particular applications in lithium-ion batteries, sodium-ion batteries, supercapacitors, dye-sensitized solar cells, and heavy-metal-ion detection and removal is reviewed herein. In addition, the remaining major challenges in the above fields are discussed and some perspectives for future research efforts in the development of MOFs are also provided. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multinary I-III-VI2 and I2-II-IV-VI4 Semiconductor Nanostructures for Photocatalytic Applications.

PubMed

Regulacio, Michelle D; Han, Ming-Yong

2016-03-15

Semiconductor nanostructures that can effectively serve as light-responsive photocatalysts have been of considerable interest over the past decade. This is because their use in light-induced photocatalysis can potentially address some of the most serious environmental and energy-related concerns facing the world today. One important application is photocatalytic hydrogen production from water under solar radiation. It is regarded as a clean and sustainable approach to hydrogen fuel generation because it makes use of renewable resources (i.e., sunlight and water), does not involve fossil fuel consumption, and does not result in environmental pollution or greenhouse gas emission. Another notable application is the photocatalytic degradation of nonbiodegradable dyes, which offers an effective way of ridding industrial wastewater of toxic organic pollutants prior to its release into the environment. Metal oxide semiconductors (e.g., TiO2) are the most widely studied class of semiconductor photocatalysts. Their nanostructured forms have been reported to efficiently generate hydrogen from water and effectively degrade organic dyes under ultraviolet-light irradiation. However, the wide band gap characteristic of most metal oxides precludes absorption of light in the visible region, which makes up a considerable portion of the solar radiation spectrum. Meanwhile, nanostructures of cadmium chalcogenide semiconductors (e.g., CdS), with their relatively narrow band gap that can be easily adjusted through size control and alloying, have displayed immense potential as visible-light-responsive photocatalysts, but the intrinsic toxicity of cadmium poses potential risks to human health and the environment. In developing new nanostructured semiconductors for light-driven photocatalysis, it is important to choose a semiconducting material that has a high absorption coefficient over a wide spectral range and is safe for use in real-world settings. Among the most promising candidates

Nanostructured ZnO-TiO2 thin film oxide as anode material in electrooxidation of organic pollutants. Application to the removal of dye Amido black 10B from water.

PubMed

El-Kacemi, Sana; Zazou, Hicham; Oturan, Nihal; Dietze, Matthias; Hamdani, Mohamed; Es-Souni, Mohammed; Oturan, Mehmet A

2017-01-01

Electrochemical oxidative degradation of diazo dye Amido black 10B (AB10B) as model pollutant in water has been studied using nanostructured ZnO-TiO 2 thin films deposited on graphite felt (GrF) substrate as anode. The influence of various operating parameters, namely the current intensity, the nature and concentration of catalyst, the nature of electrode materials (anode/cathode), and the adsorption of dye and ambient light were investigated. It was found that the oxidative degradation of AB10B followed pseudo first-order kinetics. The optimal operating conditions for the degradation of 0.12 mM (74 mg L -1 ) dye concentration and mineralization of its aqueous solution were determined as GrF-ZnO-TiO 2 thin film anode, 100 mA current intensity, and 0.1 mM Fe 2+ (catalyst) concentration. Under these operating conditions, discoloration of AB10B solution was reached at 60 min while 6 h treatment needed for a mineralization degree of 91 %. Therefore, this study confirmed that the electrochemical process is effective for the degradation of AB10B in water using nanostructured ZnO-TiO 2 thin film anodes.

Development of an eco-protocol for seaweed chlorophylls extraction and possible applications in dye sensitized solar cells

NASA Astrophysics Data System (ADS)

Armeli Minicante, S.; Ambrosi, E.; Back, M.; Barichello, J.; Cattaruzza, E.; Gonella, F.; Scantamburlo, E.; Trave, E.

2016-07-01

Seaweeds are a reserve of natural dyes (chlorophylls a, b and c), characterized by low cost and easy supply, without potential environmental load in terms of land subtraction, and also complying with the requirements of an efficient waste management policy. In particular, the brown seaweed Undaria pinnatifida is a species largely present in the Venice Lagoon area, and for it a removal strategy is actually mandatory. In this paper, we set-up an eco-protocol for the best extraction and preparation procedures of the pigment, with the aim of finding an easy and affordable method for chlorophyll c extraction, exploring at the same time the possibility of using these algae within local sustainable management integrated strategies, among which the possible use of chlorophylls as a dye source in dye sensitized solar cells (DSSCs) is investigated. Experimental results suggest that the developed protocols are useful to optimize the chlorophyll c extraction, as shown by optical absorption spectroscopy measurements. The DSSCs built with the chlorophyll extracted by the proposed eco-protocol exhibit solar energy conversion efficiencies are similar to those obtained following extraction protocols with larger environmental impacts.

Gel Electrolytes with Polyamidopyridine Dendron Modified Talc for Dye-Sensitized Solar Cells.

PubMed

Santana Andrade, Marcos A; Tiihonen, Armi; Miettunen, Kati; Lund, Peter; Nogueira, Ana F; Pastore, Heloise O

2017-06-21

Organic-inorganic hybrid layered materials are proposed as additives in a quasi-solid gel electrolyte for dye-sensitized solar cells. Talcs could provide a low-cost and environmentally friendly, as well as abundant, option as gelators. Here, talcs were prepared by functionalizing an organotalc with three polyamidopyridine dendron generations, PAMPy-talc-Gn (n = 1, 2 and 3). PAMPy dendrons grow parallel to the lamellae plane and form an organized structure by intermolecular interactions. In addition, polyiodide-dendron charge-transfer complexes were prepared onto the organotalc by adsorption of iodine. In this work, the effect of the dendron generation of PAMPy-talc and the influence of polyiodide intercalation on solar cell performance and stability were investigated. The best results were reached with the use of lowest-generation PAMPy-talc (η = 4.5 ± 0.3%, V OC = 710 ± 19 mV, J sc = 10.4 ± 0.9 mA cm -2 , and FF = 61 ± 2%): 15% higher efficiency compared to similar liquid devices. While some previously studied talcs illustrate very strong absorption of the iodide from the electrolyte, in the case of PAMPy-talc such interfering effects were absent: In a 1000 h light soaking test, the PAMPy-talc cells both with and without polyiodide intercalation demonstrated stable performances. Furthermore, the color analysis of the electrolyte indicated that the color of the electrolyte remained stable after an initial period of stabilization, which is a good indication of the compound being stable and not absorbing charge carriers from the electrolyte. The performance and stability results indicate that PAMPy-talc has potential as a gelling method for electrolytes for dye solar cells.

Mixed titanium, silicon, and aluminum oxide nanostructures as novel adsorbent for removal of rhodamine 6G and methylene blue as cationic dyes from aqueous solution.

PubMed

Pal, Umapada; Sandoval, Alberto; Madrid, Sergio Isaac Uribe; Corro, Grisel; Sharma, Vivek; Mohanty, Paritosh

2016-11-01

Mixed oxide nanoparticles containing Ti, Si, and Al of 8-15 nm size range were synthesized using a combined sol-gel - hydrothermal method. Effects of composition on the structure, morphology, and optical properties of the nanoparticles were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), microRaman spectroscopy, and diffuse reflectance spectroscopy (DRS). Dye removal abilities of the nanoparticles from aqueous solutions were tested for different cationic dyes. While all the mixed oxide nanoparticles revealed high and fast adsorption of cationic dyes, the particles containing Ti and Si turned out to be the best. The adsorption kinetics and equilibrium adsorption behavior of the adsorbate - adsorbent systems could be well described by pseudo-second-order kinetics and Langmuir isotherm model, respectively. Estimated thermodynamic parameters revealed the adsorption process is spontaneous, driven mainly by the electrostatic force between the cationic dye molecules and negative charge at nanoparticle surface. Highest dye adsorption capacity (162.96 mg MB/g) of the mixed oxide nanostructures containing Ti and Si is associated to their high specific surface area, and the presence of surface Si-O(δ-) groups, in addition to the hydroxyl groups of amorphous titania. Mixed oxide nanoparticles containing 75% Ti and 25% Si seen to be the most efficient adsorbents for removing cationic dye molecules from wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hydrothermal growth of highly monodispersed TiO2 nanoparticles: Functional properties and dye-sensitized solar cell performance

NASA Astrophysics Data System (ADS)

Navaneethan, M.; Nithiananth, S.; Abinaya, R.; Harish, S.; Archana, J.; Sudha, L.; Ponnusamy, S.; Muthamizhchelvan, C.; Ikeda, H.; Hayakawa, Y.

2017-10-01

Monodispersed anatase TiO2 nanoparticles were synthesized by hydrothermal method using citric acid as a capping agent. The effect of citric acid and the growth time on the formation of TiO2, functional properties and dye-sensitized solar cell performances were investigated. X-ray diffraction pattern (XRD) and Raman spectroscopy results revealed that the TiO2 nanoparticles possess the anatase phase. Transmission electron microscopy (TEM) measurement revealed the formation of spherical nanoparticles with monodispersity in size and morphology. An average size of 14 nm was obtained for the growth period of 15 h. The maximum efficiency (η) of dye-sensitized solar cell was achieved for TiO2 nanoparticles grown for 15 h as 7.66% which was higher than that of commercial P25 TiO2 (5.23%) and uncapped nanoparticles (3.68%).

Variation in Optoelectronic Properties of Azo Dye-Sensitized TiO 2 Semiconductor Interfaces with Different Adsorption Anchors: Carboxylate, Sulfonate, Hydroxyl and Pyridyl Groups

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

Zhang, Lei; Cole, Jacqueline M.; Dai, Chencheng

2014-05-28

The optoelectronic properties of four azo dye-sensitized TiO2 interfaces are systematically studied as a function of a changing dye anchoring group: carboxylate, sulfonate, hydroxyl, and pyridyl. The variation in optoelectronic properties of the free dyes and those in dye/TiO 2 nanocomposites are studied both experimentally and computationally, in the context of prospective dye-sensitized solar cell (DSSC) applications. Experimental UV/vis absorption spectroscopy, cyclic voltammetry, and DSSC device performance testing reveal a strong dependence on the nature of the anchor of the optoelectronic properties of these dyes, both in solution and as dye/TiO2 nanocomposites. First-principles calculations on both an isolated dye/TiO2 clustermore » model (using localized basis sets) and each dye modeled onto the surface of a 2D periodic TiO2 nanostructure (using plane wave basis sets) are presented. Detailed examination of these experimental and computational results, in terms of light harvesting, electron conversion and photovoltaic device performance characteristics, indicates that carboxylate is the best anchoring group, and hydroxyl is the worst, whereas sulfonate and pyridyl groups exhibit competing potential. Different sensitization solvents are found to affect critically the extent of dye adsorption achieved in the dye-sensitization of the TiO2 semiconductor, especially where the anchor is a pyridyl group.« less

Plasmonic gold nanoparticles for ZnO-nanotube photoanodes in dye-sensitized solar cell application

NASA Astrophysics Data System (ADS)

Abd-Ellah, Marwa; Moghimi, Nafiseh; Zhang, Lei; Thomas, Joseph. P.; McGillivray, Donald; Srivastava, Saurabh; Leung, Kam Tong

2016-01-01

Surface modification of nanostructured metal oxides with metal nanoparticles has been extensively used to enhance their nanoscale properties. The unique properties of metal nanoparticles associated with their controllable dimensions allow these metal nanoparticles to be precisely engineered for many applications, particularly for renewable energy. Here, a simple electrodeposition method to synthesize gold nanoparticles (GNPs) on electrochemically grown ZnO nanotubes (NTs) is reported. The size distribution and areal density of the GNPs can be easily controlled by manipulating the concentration of AuCl3 electrolyte solution, and the deposition time, respectively. An excellent enhancement in the optical properties of ZnO NTs surface-decorated with GNPs (GNP/ZnO-NT), especially in the visible region, is attributed to their surface plasmon resonance. The plasmonic effects of GNPs, together with the large specific surface area of ZnO NTs, can be used to significantly enhance the dye-sensitized solar cell (DSSC) properties. Furthermore, the Schottky barrier at the Au/ZnO interface could prevent electron back transfer from the conduction band of ZnO to the redox electrolyte and thus could substantially increase electron injection in the ZnO conduction band, which would further improve the overall performance of the constructed DSSCs. The GNP/ZnO-NT photoanode has been found to increase the efficiency of the DSSC significantly to 6.0% from 4.7% of the pristine ZnO-NT photoanode, together with corresponding enhancements in short-circuit current density from 10.4 to 13.1 mA cm-2 and in fill factor from 0.60 to 0.75, while the open-circuit voltage remain effectively unchanged (from 0.60 to 0.61 V). Surface decoration with GNPs therefore provides an effective approach to creating not only a high specific surface area for superior loading of dye molecules, but also higher absorbance capability due to their plasmonic effect, all of which lead to excellent performance enhancement

Dye-sensitized solar cells fabricated with black raspberry, black carrot and rosella juice

NASA Astrophysics Data System (ADS)

Tekerek, S.; Kudret, A.; Alver, Ü.

2011-10-01

In this work, dye sensitized solar cells (DSSC's) were constructed from black raspberry ( Rubus Ideaus), black carrot ( Daucuscarota L.) and rosella juice ( Hibiscus Sabdariffa L.). In order to fabricate a DSSC the fluorine-doped tin (IV) oxide (FTO) thin films obtained by using spray pyrolysis technique were used as a substrate. TiO2 films on FTO layers were prepared by doctor-blading technique. Platinum-coated counter electrode and liquid Iodide/Iodine electrolyte solution were used to fabricate DSSC's. The efficiencies of solar cells produced with black carrot, rosella and black raspberry juice were calculated as 0.25%, 0.16% and 0.16% respectively, under a sunny day in Kahramanmaraş-Turkey.

Bifacial dye-sensitized solar cells: A strategy to enhance overall efficiency based on transparent polyaniline electrode

PubMed Central

Wu, Jihuai; Li, Yan; Tang, Qunwei; Yue, Gentian; Lin, Jianming; Huang, Miaoliang; Meng, Lijian

2014-01-01

Dye-sensitized solar cell (DSSC) is a promising solution to global energy and environmental problems because of its clean, low-cost, high efficiency, good durability, and easy fabrication. However, enhancing the efficiency of the DSSC still is an important issue. Here we devise a bifacial DSSC based on a transparent polyaniline (PANI) counter electrode (CE). Owing to the sunlight irradiation simultaneously from the front and the rear sides, more dye molecules are excited and more carriers are generated, which results in the enhancement of short-circuit current density and therefore overall conversion efficiency. The photoelectric properties of PANI can be improved by modifying with 4-aminothiophenol (4-ATP). The bifacial DSSC with 4-ATP/PANI CE achieves a light-to-electric energy conversion efficiency of 8.35%, which is increased by ~24.6% compared to the DSSC irradiated from the front only. This new concept along with promising results provides a new approach for enhancing the photovoltaic performances of solar cells. PMID:24504117

Photoactive layer based on T-shaped benzimidazole dyes used for solar cell: from photoelectric properties to molecular design

NASA Astrophysics Data System (ADS)

Xu, Beibei; Li, Yuanzuo; Song, Peng; Ma, Fengcai; Sun, Mengtao

2017-03-01

Three benzimidazole-based organic dyes, possessing the same triphenylamine donors and cyanoacrylic acid acceptors with the bithiophene π-bridges combined in different nuclear positions of benzimidazole, were investigated in the utility of dye-sensitizer solar cells. The structure, molecular orbital and energy, absorption spectra and some important parameters (such as light harvesting efficiency (LHE), electron injection driving force, the electron injection time, chemical reactivity parameters, vertical dipole moment as well as interaction models of dye-I2) were obtained according to Newns-Anderson model and DFT calculation. The process and strength of charge transfer and separation were visualized with charge different density and index of spatial extent (S, D and Δq). Current work paid attention to the new T-shaped dyes to reveal the relation between the structure and photoelectric performance. Furthermore, nine dyes (substitution of alkyl chains and π-bridges) have been designed and characterized to screen promising sensitizer candidates with excellent photo-electronic properties.

Solar photocatalysis for treatment of Acid Yellow-17 (AY-17) dye contaminated water using Ag@TiO2 core-shell structured nanoparticles.

PubMed

Khanna, Ankita; Shetty K, Vidya

2013-08-01

Wastewater released from textile industries causes water pollution, and it needs to be treated before discharge to the environment by cost effective technologies. Solar photocatalysis is a promising technology for the treatment of dye wastewater. The Ag@TiO2 nanoparticles comprising of Ag core and TiO2 shell (Ag@TiO2) have unique photocatalytic property of inhibition of electron-hole recombination and visible light absorption, which makes it a promising photocatalyst for use in solar photocatalysis and with higher photocatalytic rate. Therefore, in the present work, the Ag@TiO2 nanoparticles synthesized by one pot method with postcalcination step has been used for the degradation of Acid Yellow-17 (AY-17) dye under solar light irradiation. The Ag@TiO2 nanoparticles were characterized using thermogravimetric-differential thermal analysis, X-ray diffraction, transmission electron microscopy, selected area electron diffraction, and energy dispersive X-ray analysis. The catalyst has been found to be very effective in solar photocatalysis of AY-17, as compared to other catalysts. The effects of pH, catalyst loading, initial dye concentration, and oxidants on photocatalysis were also studied. The optimized parameters for degradation of AY-17 using Ag@TiO2 were found to be pH 3, dye/catalyst ratio of 1:10 (g/g), and 2 g/L of (NH4)2S2O8 as oxidant. Efficient decolorization and mineralization of AY-17 was achieved. The kinetics of color, total organic carbon, and chemical oxygen demand removal followed the Langmuir-Hinshelwood model. Ag@TiO2 catalyst can be reused thrice without much decline in efficiency. The catalyst exhibited its potential as economic photocatalyst for treatment of dye wastewater.

TiO2 dye sensitized solar cell (DSSC): linear relationship of maximum power point and anthocyanin concentration

NASA Astrophysics Data System (ADS)

Ahmadian, Radin

2010-09-01

This study investigated the relationship of anthocyanin concentration from different organic fruit species and output voltage and current in a TiO2 dye-sensitized solar cell (DSSC) and hypothesized that fruits with greater anthocyanin concentration produce higher maximum power point (MPP) which would lead to higher current and voltage. Anthocyanin dye solution was made with crushing of a group of fresh fruits with different anthocyanin content in 2 mL of de-ionized water and filtration. Using these test fruit dyes, multiple DSSCs were assembled such that light enters through the TiO2 side of the cell. The full current-voltage (I-V) co-variations were measured using a 500 Ω potentiometer as a variable load. Point-by point current and voltage data pairs were measured at various incremental resistance values. The maximum power point (MPP) generated by the solar cell was defined as a dependent variable and the anthocyanin concentration in the fruit used in the DSSC as the independent variable. A regression model was used to investigate the linear relationship between study variables. Regression analysis showed a significant linear relationship between MPP and anthocyanin concentration with a p-value of 0.007. Fruits like blueberry and black raspberry with the highest anthocyanin content generated higher MPP. In a DSSC, a linear model may predict MPP based on the anthocyanin concentration. This model is the first step to find organic anthocyanin sources in the nature with the highest dye concentration to generate energy.

Rational Molecular Engineering of Indoline-Based D-A-π-A Organic Sensitizers for Long-Wavelength-Responsive Dye-Sensitized Solar Cells.

PubMed

Zhang, Weiwei; Wu, Yongzhen; Zhu, Haibo; Chai, Qipeng; Liu, Jingchuan; Li, Hui; Song, Xiongrong; Zhu, Wei-Hong

2015-12-09

Indoline-based D-A-π-A organic sensitizers are promising candidates for highly efficient and long-term stable dye-sensitized solar cells (DSSCs). In order to further broaden the spectral response of the known indoline dye WS-2, we rationally engineer the molecular structure through enhancing the electron donor and extending the π-bridge, resulting in two novel indoline-based D-A-π-A organic sensitizers WS-92 and WS-95. By replacing the 4-methylphenyl group on the indoline donor of WS-2 with a more electron-rich carbazole unit, the intramolecular charge transfer (ICT) absorption band of dye WS-92 is slightly red-shifted from 550 nm (WS-2) to 554 nm (WS-92). In comparison, the incorporation of a larger π-bridge of cyclopentadithiophene (CPDT) unit in dye WS-95 not only greatly bathochromatically tunes the absorption band to 574 nm but also largely enhances the molar extinction coefficients (ε), thus dramatically improving the light-harvesting capability. Under the standard global AM 1.5 solar light condition, the photovoltaic performances of both organic dyes have been evaluated in DSSCs on the basis of the iodide/triiodide electrolyte without any coadsorbent or cosensitizer. The DSSCs based on WS-95 display better device performance with power conversion efficiency (η) of 7.69%. The additional coadsorbent in the dye bath of WS-95 does not improve the photovoltaic performance, indicative of its negligible dye aggregation, which can be rationalized by the grafted dioctyl chains on the CPDT unit. The cosensitization of WS-95 with a short absorption wavelength dye S2 enhances the IPCE and improves the η to 9.18%. Our results indicate that extending the π-spacer is more rational than enhancing the electron donor in terms of broadening the spectral response of indoline-based D-A-π-A organic sensitizers.

Present status of solid state photoelectrochemical solar cells and dye sensitized solar cells using PEO-based polymer electrolytes

NASA Astrophysics Data System (ADS)

Singh, Pramod Kumar; Nagarale, R. K.; Pandey, S. P.; Rhee, H. W.; Bhattacharya, Bhaskar

2011-06-01

Due to energy crises in the future, much effort is being directed towards alternate sources. Solar energy is accepted as a novel substitute for conventional sources of energy. Out of the long list of various types of solar cells available on the market, solid state photoelectrochemical solar cells (SSPECs) and dye sensitized solar cells (DSSCs) are proposed as an alternative to costly crystalline solar cell. This review provides a common platform for SSPECs and DSSCs using polymer electrolyte, particularly on polyethylene oxide (PEO)-based polymer electrolytes. Due to numerous advantageous properties of PEO, it is frequently used as an electrolyte in both SSPECs as well as DSSCs. In DSSCs, so far high efficiency (more than 11%) has been obtained only by using volatile liquid electrolyte, which suffers many disadvantages, such as corrosion, leakage and evaporation. The PEO-based solid polymer proves its importance and could be used to solve the problems stated above. The recent developments in SSPECs and DSSCs using modified PEO electrolytes by adding nano size inorganic fillers, blending with low molecular weight polymers and ionic liquid (IL) are discussed in detail. The role of ionic liquid in modifying the electrical, structural and photoelectrochemical properties of PEO polymer electrolytes is also described.

Multiscale Modeling of Plasmon-Enhanced Power Conversion Efficiency in Nanostructured Solar Cells.

PubMed

Meng, Lingyi; Yam, ChiYung; Zhang, Yu; Wang, Rulin; Chen, GuanHua

2015-11-05

The unique optical properties of nanometallic structures can be exploited to confine light at subwavelength scales. This excellent light trapping is critical to improve light absorption efficiency in nanoscale photovoltaic devices. Here, we apply a multiscale quantum mechanics/electromagnetics (QM/EM) method to model the current-voltage characteristics and optical properties of plasmonic nanowire-based solar cells. The QM/EM method features a combination of first-principles quantum mechanical treatment of the photoactive component and classical description of electromagnetic environment. The coupled optical-electrical QM/EM simulations demonstrate a dramatic enhancement for power conversion efficiency of nanowire solar cells due to the surface plasmon effect of nanometallic structures. The improvement is attributed to the enhanced scattering of light into the photoactive layer. We further investigate the optimal configuration of the nanostructured solar cell. Our QM/EM simulation result demonstrates that a further increase of internal quantum efficiency can be achieved by scattering light into the n-doped region of the device.

The layer boundary effect on multi-layer mesoporous TiO 2 film based dye sensitized solar cells

DOE PAGES

Xu, Feng; Zhu, Kai; Zhao, Yixin

2016-10-10

Multi-layer mesoporous TiO 2 prepared by screen printing is widely used for fabrication of high-efficiency dye-sensitized solar cells (DSSCs). Here, we compare the three types of ~10 um thick mesoporous TiO 2 films, which were screen printed as 1-, 2- and 4-layers using the same TiO 2 nanocrystal paste. The layer boundary of the multi-layer mesoporous TiO 2 films was observed in the cross-section SEM. The existence of a layer boundary could reduce the photoelectron diffusion length with the increase of layer number. However, the photoelectron diffusion lengths of the Z907 dye sensitized solar cells based on these different layeredmore » mesoporous TiO 2 films are all longer than the film thickness. Consequently, the photovoltaic performance seems to have little dependence on the layer number of the multi-layer TiO 2 based DSSCs.« less

The layer boundary effect on multi-layer mesoporous TiO 2 film based dye sensitized solar cells

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

Xu, Feng; Zhu, Kai; Zhao, Yixin

Multi-layer mesoporous TiO 2 prepared by screen printing is widely used for fabrication of high-efficiency dye-sensitized solar cells (DSSCs). Here, we compare the three types of ~10 um thick mesoporous TiO 2 films, which were screen printed as 1-, 2- and 4-layers using the same TiO 2 nanocrystal paste. The layer boundary of the multi-layer mesoporous TiO 2 films was observed in the cross-section SEM. The existence of a layer boundary could reduce the photoelectron diffusion length with the increase of layer number. However, the photoelectron diffusion lengths of the Z907 dye sensitized solar cells based on these different layeredmore » mesoporous TiO 2 films are all longer than the film thickness. Consequently, the photovoltaic performance seems to have little dependence on the layer number of the multi-layer TiO 2 based DSSCs.« less

Theoretical studies on a new pattern of laser-driven systems: towards elucidation of direct photo-injection in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Mishima, Kenji; Yamashita, Koichi

2011-03-01

We theoretically and numerically investigated a new type of analytically solvable laser-driven systems inspired by electron-injection dynamics in dye-sensitized solar cells. The simple analytical expressions were found to be useful for understanding the difference between dye excitation and direct photo-injection occurring between dye molecule and semiconductor nanoparticles. More importantly, we propose a method for discriminating experimentally dye excitation and direct photo-injection by using time-dependent fluorescence. We found that dye excitation shows no significant quantum beat whereas the direct photo-injection shows a significant quantum beat. This work was supported by Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST) ``Development of Organic Photovoltaics toward a Low-Carbon Society,'' Cabinet Office, Japan.

Modulated charge injection in p-type dye-sensitized solar cells using fluorene-based light absorbers.

PubMed

Liu, Zonghao; Xiong, Dehua; Xu, Xiaobao; Arooj, Qudsia; Wang, Huan; Yin, Liyuan; Li, Wenhui; Wu, Huaizhi; Zhao, Zhixin; Chen, Wei; Wang, Mingkui; Wang, Feng; Cheng, Yi-Bing; He, Hongshan

2014-03-12

In this study, new pull-push arylamine-fluorene based organic dyes zzx-op1, zzx-op2, and zzx-op3 have been designed and synthesized for p-type dye-sensitized solar cells (p-DSCs). In zzx-op1, a di(p-carboxyphenyl)amine (DCPA) was used as an electron donor, a perylenemonoimide (PMID) as an electron acceptor, and a fluorene (FLU) unit with two aliphatic hexyl chains as a π-conjugated linker. In zzx-op2 and zzx-op3, a 3,4-ethylenedioxythiophene (EDOT) and a thiophene were inserted consecutively between PMID and FLU to tune the energy levels of the frontier molecular orbitals of the dyes. The structural modification broadened the spectral coverage from an onset of 700 nm for zzx-op1 to 750 nm for zzx-op3. The electron-rich EDOT and thiophene lifted up the HOMO (highest occupied molecular orbital) levels of zzx-op2 and zzx-op3, making their potential more negative than zzx-op1. When three dyes were employed in p-type DSCs with I(-)/I3(-) as a redox couple and NiO nanoparticles as hole materials, zzx-op1 exhibited impressive energy conversion efficiency of 0.184% with the open-circuit voltage (VOC) of 112 mV and the short-circuit current density (JSC) of 4.36 mA cm(-2) under AM 1.5G condition. Density functional theory calculations, transient photovoltage decay measurements, and electrochemical impedance spectroscopic studies revealed that zzx-op1 sensitized solar cell exhibited much higher charge injection efficiency (90.3%) than zzx-op2 (53.9%) and zzx-op3 (39.0%), indicating a trade-off between spectral broadening and electron injection driving force in p-type DSCs.

Improved performance of anodic titanium oxide nanotube arrays synthesized by sonoelectrochemical anodization method for dye-sensitized solar cells