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Cell Devices (cell + device)

Distribution by Scientific Domains

Polymers and Materials Science	33%

Kinds of Cell Devices

solar cell device

Selected Abstracts

A 4,% Efficient Dye-Sensitized Solar Cell Fabricated from Cathodically Electrosynthesized Composite Titania Films,

ADVANCED MATERIALS, Issue 21 2003
J. Yamamoto
Cathodically electrosynthesized TiO2 films (see Figure) containing occluded Degussa P-25 titania particles can yield short-circuit current densities as high as 10.5 mA,cm,2, an open-circuit photovoltage of 690 mV, a fill factor of 57.3,%, and a photovoltaic efficiency of 4.13,% under simulated air mass 1.5 (100 mW,cm,2) sunlight in a dye-sensitized solar cell device. [source]

Two-dimensional simulation of GaInP/GaAs/Ge triple junction solar cell

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 5 2007
Z. Q. Li
Abstract In this work, two-dimensional simulation has been performed on the triple-junction (TJ) GaInP/GaAs/Ge solar cell devices based on the Crosslight APSYS with improved tunnel junction model. The APSYS simulator solves several interwoven equations including the basic Poisson's equation, and drift-diffusion current equations for electrons and holes. Basic physical quantities like band diagrams, optical absorption and generation are calculated. The simulated IV characteristics and offset voltage agree well with the published experimental results for TJ GaInP/GaAs/Ge solar cell device. The quantum efficiency spectra have also been computed. Possible design optimization issues to enhance the quantum efficiency have also been discussed with respect to some applicable features of Crosslight APSYS. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Very high efficiency solar cell modules

PROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 1 2009
Allen Barnett
Abstract The Very High Efficiency Solar Cell (VHESC) program is developing integrated optical system,PV modules for portable applications that operate at greater than 50% efficiency. We are integrating the optical design with the solar cell design, and have entered previously unoccupied design space. Our approach is driven by proven quantitative models for the solar cell design, the optical design, and the integration of these designs. Optical systems efficiency with an optical efficiency of 93% and solar cell device results under ideal dichroic splitting optics summing to 42·7,±,2·5% are described. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Influence of a pore-former and PTFE in the performance of the direct ethanol fuel cell

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 1 2009
S. K. Biswas
Abstract The direct ethanol fuel cell (DEFC) is a promising fuel cell device, which could provide power to portable and microelectronic equipment in the future. In the present investigation, the influence of a pore-former, polytetrafluoroethylene (PTFE) and catalyst loadings in the electrocatalyst of the anode on DEFC performance is studied. The decal transfer method is used to prepare the membrane electrode assembly (MEA) using PtRu/C (40:20% by wt) as the anode catalyst, and Pt/C (40% by wt) as the cathode catalyst, a pore-former, PTFE dispersion and Nafion ionomer. The pore-former used is 10% (by wt) NaHCO3 in the catalyst ink during the preparation of MEA. The voltage-current characteristics of DEFC were monitored at different loadings of the catalyst, PTFE and a pore-former in MEA. The DEFC performance improved with the use of a pore-former and higher loading of PTFE in MEA. Higher DEFC performance is obtained because PTFE, along with the network of pores in the anode side allowed easy removal of reaction species, thereby rendering the catalyst site available for ethanol oxidation. Further, the use of a pore-former and PTFE at the anode allowed higher loading of electrocatalyst resulting in an increase in the performance of DEFC. The DEFC, with 1 mg cm,2 of catalyst loading at the anode and cathode, 10% (by wt) NaHCO3 of a pore-former, 20% (by wt) PTFE loading in catalyst ink gives maximum power density of 8.5 mW cm,2 at a current density of 31.3 mA cm,2. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd. [source]

Positively Charged Iridium(III) Triazole Derivatives as Blue Emitters for Light-Emitting Electrochemical Cells

ADVANCED FUNCTIONAL MATERIALS, Issue 11 2010
Mathias Mydlak
Abstract Cationic blue-emitting complexes with (2,4-difluoro)phenylpyridine and different 1,2,3-triazole ligands are synthesized with different counterions. The influence of the substituents on the triazole ligand is investigated as well as the influence of the counterions. The substituents do not change the emission energy but, in some cases, slightly modify the excited-state lifetimes and the emission quantum yields. The excited-state lifetimes, in apolar solvents, are slightly dependent on the nature of the counterion. A crystal structure of one of the compounds confirms the geometry and symmetry postulated on the basis of the other spectroscopic data. Light-emitting electrochemical cell devices are prepared and the recorded emission is the bluest with the fastest response time ever reported for iridium complexes. [source]

Inverse Opal Structure of Nitrogen-Doped Titanium Oxide with Enhanced Visible-Light Photocatalytic Activity

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2008
Qi Li
Nitrogen-doped titanium oxide inverse opal structure was synthesized to combine both chemical and physical modifications on n -TiO2 by the polystyrene sphere self-assembly followed by a sol,gel process. Enhanced visible-light absorption and subsequently enhanced photodegradation efficiency were observed in this unique structure, which can be attributed to both nitrogen-doping effect and inverse opal structure effect. Our work suggests that the coupling of photonic band gap structure with photocatalytic materials is a promising approach to achieve maximum enhancement for various photocatalytic materials, especially for environmental applications and solar cell devices. [source]

A New Poly(2,7-Dibenzosilole) Derivative in Polymer Solar Cells

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 22 2007
Pierre-Luc T. Boudreault
Abstract A new soluble conjugated copolymer based on 2,7-dibenzosilole and 4,7-dithien-2-yl-2,1,3-benzothiadiazole units has been synthesized (PBSDTBT). Bulk heterojunction solar cell devices are fabricated using this material as the donor and [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) as the acceptor. The power conversion efficiency is 1.6% under AM1.5 illumination. This material also shows a good VOC (0.97 V). The results are quite promising considering the relatively large bandgap (1.9 eV) of this polymer. [source]

Two-dimensional simulation of GaInP/GaAs/Ge triple junction solar cell

Influence from front contact sheet resistance on extracted diode parameters in CIGS solar cells

PROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 2 2008
Ulf Malm
Abstract The extraction of one-diode model parameters from a current,voltage (J,V) curve is problematic, since the model is one-dimensional while real devices are indeed three-dimensional. The parameters obtained by fitting the model curve to experimental data depend on how the current is collected, and more specifically the geometry of the contact. This is due to the non-uniform lateral current flow in the window layers, which leads to different parts of the device experiencing different front contact voltage drop, and hence different operating points on the ideal J,V curve. In this work, finite element simulations of three-dimensional contact structures are performed and compared to experimental data on Cu(In,Ga)Se2 -based solar cell devices. It is concluded that the lateral current flow can influence the extracted parameters from the one-diode model significantly if the resistivity of the front contact material is high, or if there is no current collecting grid structure. These types of situations may appear in damp heat-treated cells and module type cells, respectively. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Screen-print selective diffusions for high-efficiency industrial silicon solar cells

PROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 1 2008
Matthew Edwards
Abstract Screen-print diffusion pastes present an industrially applicable alternative to conventional techniques of dopant deposition. Several commercially available screen-print dopant pastes are assessed for their suitability in forming heavy selective diffusions for use under metal contacts in silicon solar cells. Pastes are assessed in terms of their ease of application, their ability to form heavy diffusions with low sheet resistances, and their ability to maintain high post-diffusion wafer lifetimes. Potential for the use of dopant pastes in high-efficiency solar cell devices is investigated using photoconductance (PC) measurements and photoluminescence (PL) images. It is found that under certain conditions, screen-print dopant pastes, particularly phosphorus paste, have potential to form effective selective diffusions without significantly compromising performance in high-efficiency solar cells. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Atomic layer deposition of Zn1,xMgxO buffer layers for Cu(In,Ga)Se2 solar cells

PROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 3 2007
T. Törndahl
Abstract Fabrication of Zn1,xMgxO films by atomic layer deposition (ALD) has been studied for use as buffer layers in Cu(In,Ga)Se2 (CIGS)-based solar cell devices. The Zn1,xMgxO films were grown using diethyl zinc, bis-cyclopentadienyl magnesium and water as precursors in the temperature range from 105 to 180°C. Single-phase ZnO-like films were obtained for x,<,0·2, followed by a two phase region of ZnO- and MgO-like structures for higher Mg concentrations. Increasing optical band gaps of up to above 3·8,eV were obtained for Zn1,xMgxO with increasing x. It was found that the composition of the Zn1,xMgxO films varied as an effect of deposition temperature as well as by increasing the relative amount of magnesium precursor pulses during film growth. Completely Cd-free CIGS-based solar cells devices with ALD-Zn1,xMgxO buffer layers were fabricated and showed efficiencies of up to 14·1%, which was higher than that of the CdS references. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Highly-efficient Cd-free CuInS2 thin-film solar cells and mini-modules with Zn(S,O) buffer layers prepared by an alternative chemical bath process

PROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 6 2006
A. Ennaoui
Abstract Recent progress in fabricating Cd- and Se-free wide-gap chalcopyrite thin-film solar devices with Zn(S,O) buffer layers prepared by an alternative chemical bath process (CBD) using thiourea as complexing agent is discussed. Zn(S,O) has a larger band gap (Eg,=,3·6,3·8,eV) than the conventional buffer material CdS (Eg,=,2·4,eV) currently used in chalcopyrite-based thin films solar cells. Thus, Zn(S,O) is a potential alternative buffer material, which already results in Cd-free solar cell devices with increased spectral response in the blue wavelength region if low-gap chalcopyrites are used. Suitable conditions for reproducible deposition of good-quality Zn(S,O) thin films on wide-gap CuInS2 (,CIS') absorbers have been identified for an alternative, low-temperature chemical route. The thickness of the different Zn(S,O) buffers and the coverage of the CIS absorber by those layers as well as their surface composition were controlled by scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray excited Auger electron spectroscopy. The minimum thickness required for a complete coverage of the rough CIS absorber by a Zn(S,O) layer deposited by this CBD process was estimated to ,15,nm. The high transparency of this Zn(S,O) buffer layer in the short-wavelength region leads to an increase of ,1,mA/cm2 in the short-circuit current density of corresponding CIS-based solar cells. Active area efficiencies exceeding 11·0% (total area: 10·4%) have been achieved for the first time, with an open circuit voltage of 700·4,mV, a fill factor of 65·8% and a short-circuit current density of 24·5,mA/cm2 (total area: 22·5,mA/cm2). These results are comparable to the performance of CdS buffered reference cells. First integrated series interconnected mini-modules on 5,×,5,cm2 substrates have been prepared and already reach an efficiency (active area: 17·2,cm2) of above 8%. Copyright © 2006 John Wiley & Sons, Ltd. [source]

A comparative study of defect states in evaporated and selenized CIGS(S) solar cells

PROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 7 2005
P. K. Johnson
Abstract Current-voltage, admittance spectroscopy, and drive-level capacitance profiling measurements were taken on Cu(In1,xGax)(Se1,ySy)2 solar cell devices. The devices were made using two different types of absorbers. One set of absorbers was deposited via physical vapor deposition, while the other set of absorbers was made by selenization of metal precursors. Additionally, each type of absorber was completed with one of two different types of buffer treatments: a CdS layer or a cadmium partial electrolyte surface modification. The devices with the evaporated absorbers had larger values of VOC, higher carrier densities, lower densities of trapping defects, and likely shallower gap states. Results were qualitatively similar for the CdS and partial electrolyte buffers. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Solution Processable Fluorenyl Hexa- peri -hexabenzocoronenes in Organic Field-Effect Transistors and Solar Cells

ADVANCED FUNCTIONAL MATERIALS, Issue 6 2010
Wallace W. H. Wong
Abstract The organization of organic semiconductor molecules in the active layer of organic electronic devices has important consequences to overall device performance. This is due to the fact that molecular organization directly affects charge carrier mobility of the material. Organic field-effect transistor (OFET) performance is driven by high charge carrier mobility while bulk heterojunction (BHJ) solar cells require balanced hole and electron transport. By investigating the properties and device performance of three structural variations of the fluorenyl hexa- peri -hexabenzocoronene (FHBC) material, the importance of molecular organization to device performance was highlighted. It is clear from 1H NMR and 2D wide-angle X-ray scattering (2D WAXS) experiments that the sterically demanding 9,9-dioctylfluorene groups are preventing ,,, intermolecular contact in the hexakis-substituted FHBC 4. For bis-substituted FHBC compounds 5 and 6, ,,, intermolecular contact was observed in solution and hexagonal columnar ordering was observed in solid state. Furthermore, in atomic force microscopy (AFM) experiments, nanoscale phase separation was observed in thin films of FHBC and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) blends. The differences in molecular and bulk structural features were found to correlate with OFET and BHJ solar cell performance. Poor OFET and BHJ solar cells devices were obtained for FHBC compound 4 while compounds 5 and 6 gave excellent devices. In particular, the field-effect mobility of FHBC 6, deposited by spin-casting, reached 2.8,×,10,3,cm2 V,1 s and a power conversion efficiency of 1.5% was recorded for the BHJ solar cell containing FHBC 6 and PC61BM. [source]