Effect of Cu Deficiency on CuIn1-xGaxSe2 and High-efficiency Photovoltaic Solar Cells

2005 ◽  
Vol 865 ◽  
Author(s):  
Sung-Ho Han ◽  
Falah S. Hasoon ◽  
Joel W. Pankow ◽  
Allen M. Hermann ◽  
Dean H. Levi
Keyword(s):  
Thin Film ◽  
High Efficiency ◽  
Composition Range ◽  
Valence Band Maximum ◽  
Repulsive Interaction ◽  
Polycrystalline Thin Film ◽  
Band Maximum ◽  
Cu Deficiency ◽  
Wide Range ◽  
Photovoltaic Solar Cells

AbstractWe report the results of our studies on the optical and electronic structure of a wide range of polycrystalline thin-film CuIn1-xGaxSe2 (CIGS) alloys. The composition range includes CIS and nearly stoichiometric (slightly Cu-poor) (24.3±0.3 at.% Cu) CIGS with x values located around the value that has the best efficiency (x ∼ 0.28). Relative to nearly stoichiometric CIS and CIGS, we find a reduction in the absorption strength in the spectral range 1-3 eV. This reduction can be explained in terms of the predominance of Cu 3d and Se 4p states at the valence band maximum (VBM). In addition, Cu-poor CIS and CIGS materials show an increase in bandgap because the p-d repulsive interaction in Cu-poor CIGS is less than that in nearly stoichiometric CIGS. High efficiency is discussed in terms of optical properties.

Magnetron Sputtering for Low-temperature Deposition of CdTe-based Photovoltaics

2003 ◽  
Vol 763 ◽  
Author(s):  
Alvin D. Compaan
Keyword(s):  
Thin Film ◽  
Magnetron Sputtering ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
High Efficiency ◽  
Chemical Vapor ◽  
Rf Magnetron Sputtering ◽  
Polycrystalline Thin Film ◽  
Thin Film Semiconductors ◽  
Temperature Deposition

AbstractAlthough the deposition over large areas of polycrystalline thin-film semiconductors such as CdTe is possible by a variety of methods including close spaced sublimation, vapor transport deposition, physical vapor deposition, organometallic chemical vapor deposition, and electrodeposition, the use of a plasma-based method such as magnetron sputtering can have significant advantages. In this paper I review recent results from our group in the fabrication of CdS/CdTe cells using rf magnetron sputtering and discuss some of the advantages that appear possible from the use of sputtering methods in this class of materials. Some of these advantages are particularly relevant as the polycrystalline thin-film community address issues related to the challenges of fabricating high efficiency tandem cells with efficiencies over 25%. Recently we have achieved: improvements in sputtered cell performance with cells based on commercial SnO2:F as well as on substrates with our own sputtered ZnO:Al, progress in the use of reactive sputtering for the deposition of oxygen alloys of CdS and N-doped layers of ZnTe, and progress in the sputtering of wider and narrower bandgap alloys of CdTe with Zn, Mn, and Hg. Details of the sputtering process and some of the recent achievements are discussed below.

High-Efficiency CdTe Polycrystalline Thin-Film Solar Cells with an Ultra-Thin CuxTe Transparent Back-Contact

2005 ◽  
Vol 865 ◽  
Author(s):  
X. Wu ◽  
J. Zhou ◽  
A. Duda ◽  
J. C. Keane ◽  
T.A. Gessert ◽  
...  
Keyword(s):  
Thin Film ◽  
Near Infrared ◽  
High Efficiency ◽  
State Of The Art ◽  
Wavelength Region ◽  
Back Contact ◽  
Infrared Transmission ◽  
Polycrystalline Thin Film ◽  
Tandem Cell ◽  
Junction Device

AbstractTo fabricate a high-efficiency polycrystalline thin-film tandem cell, the most critical work is to make a high-efficiency top cell (>15%) with high bandgap (Eg=1.5-1.8 eV) and high transmission (T>70%) in the near-infrared (NIR) wavelength region. The CdTe cell is one of the candidates for the top cell, because CdTe state-of-the-art single-junction devices with efficiencies of more than 16% are available, although its bandgap (1.48 eV) is slightly lower for a top cell in a dual-junction device. In this paper, we focus on the development of an ultra-thin, low-bandgap CuxTe transparent back-contact to produce high-efficiency CdTe cells with high NIR transmission. We have achieved an NREL-confirmed 13.9%-efficient CdTe transparent solar cell with an infrared transmission of ~50% and a CdTe/CIS polycrystalline mechanically stacked thin-film tandem cell with an NREL-confirmed efficiency of 15.3%.

scholarly journals Surface Plasmon Enhanced Light Trapping in Metal/Silicon Nanobowl Arrays for Thin Film Photovoltaics

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Ruinan Sun ◽  
Haoxin Fu ◽  
Jiang Wang ◽  
Yachun Wang ◽  
Xingchen Du ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
High Efficiency ◽  
Light Trapping ◽  
Short Circuit ◽  
Silicon Solar Cells ◽  
Periodic Arrays ◽  
High Efficiency Solar Cells ◽  
Wide Range ◽  
Significant Cost Reduction

Enhancing the light absorption in thin film silicon solar cells with nanophotonic and plasmonic structures is important for the realization of high efficiency solar cells with significant cost reduction. In this work, we investigate periodic arrays of conformal metal/silicon nanobowl arrays (MSNBs) for light trapping applications in silicon solar cells. They exhibited excellent light-harvesting ability across a wide range of wavelengths up to infrared regimes. The optimized structure (MSNBsH) covered by SiO2 passivation layer and hemisphere Ag back reflection layer has a maximal short-circuit density (Jsc) 25.5 mA/cm2, which is about 88.8% higher than flat structure counterpart, and the light-conversion efficiency (η) is increased two times from 6.3% to 12.6%. The double-side textures offer a promising approach to high efficiency ultrathin silicon solar cells.

scholarly journals Study and Analytical Modeling of the Influence of Technological and Geometric Parameters on the Performance of Ga0:67In0:33P=GaAs=Ga0:70In0:30As Tri-junction Photovoltaic Solar Cells

2020 ◽  
pp. 66-78
Author(s):  
N. Ndorere ◽  
B. Kounouhewa ◽  
M.B. Agbomahena
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
High Efficiency ◽  
Geometric Parameters ◽  
Cell Structures ◽  
In Doping ◽  
Wide Range ◽  
Proportional Increase ◽  
The One ◽  
Photovoltaic Solar Cells

In the context of global energy consumption, the production of photovoltaic solar energy remains very low. One solution to this problem is to use multi-junction solar cells with high efficiency. Efforts are being made to increase the efficiency of solar cells and reduce their cost of production. In order to optimize the performance of multi-junction solar cells, this paper presents an analytical model allowing to study and model the influence of technological and geometric parameters on the performance of tri-junction solar cells Ga0:67In0:33P=GaAs=Ga0:70In0:30As. These parameters are the thickness, doping and Gap energy of the three sub-cells making up the tri-junction solar structure. The thicknesses and doping of the emitters (bases) of the sub-cells are varied and chosen in order to optimize the efficiency of the Trijunction Solar Cell (TJSC) Ga0:67In0:33P=GaAs=Ga0:70In0:30As. The one hand, the base doping (emitter) is selected so as to minimize the dark current and the other hand,to reduce the resistive losses in this region. As for the thickness, it is chosen so as to minimize the recombination phenomena. The simulation results show that for a given thickness, the sub-cell efficiencies have maximums which evolve with the increase in doping. If the doping of the base (or emitter) of the sub-cells increases, there follows a proportional increase in the efficiency. In addition, when the optimal doping and thickness of the bases (or emitters) are reached, above these, they can vary over a wide range without considerably modifying the efficiency of the solar cell. This point about the tolerance ranges is very important for the practical realization of Photovoltaic solar cell structures. These results also show that the optimal performance of the Tri-junction Solar Cell are obtained for the relatively low thicknesses of the bases (or emitters) (100nm-700nm) with high doping values(Nb = 8e + 18cm

Zn(O,OH) layers in chalcopyrite thin-film solar cells: Valence-band maximum versus composition

2005 ◽  
Vol 98 (5) ◽  
pp. 053702 ◽  
Author(s):  
M. Bär ◽  
J. Reichardt ◽  
A. Grimm ◽  
I. Kötschau ◽  
I. Lauermann ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Valence Band ◽  
Valence Band Maximum ◽  
Thin Film Solar Cells ◽  
Band Maximum

High-Efficiency Polycrystalline Thin Film Tandem Solar Cells

2015 ◽  
Vol 6 (14) ◽  
pp. 2676-2681 ◽  
Author(s):  
Lukas Kranz ◽  
Antonio Abate ◽  
Thomas Feurer ◽  
Fan Fu ◽  
Enrico Avancini ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
High Efficiency ◽  
Polycrystalline Thin Film ◽  
Tandem Solar Cells

scholarly journals Photovoltaics with Emphasis on CdTe Solar Cells and Modules

2020 ◽  
Author(s):  
Alessio Bosio
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
High Efficiency ◽  
Inorganic Materials ◽  
Thin Film Solar Cells ◽  
Polycrystalline Thin Film ◽  
Photovoltaic Modules ◽  
Cdte Solar Cells ◽  
High Efficiency Solar Cells ◽  
Photovoltaic Technologies

A brief overview of the main photovoltaic technologies is chronologically presented. Single-crystal and multi-crystalline, epitaxial and thin film inorganic materials are widely used as absorbers in high efficiency solar cells and modules. A schematic representation of the principal devices developed in more then 70 years of research will be displayed and commented. Among thin-film technology, cadmium telluride (CdTe) has achieved a truly impressive development that can commercially compete with silicon, which is still the king of the market. Solar cells made on a laboratory scale have reached efficiencies close to 22%, while modules made with fully automated in-line machines show efficiencies above 18%. Based on the research developed in our laboratory, the fabrication processes of both CdTe polycrystalline thin-film solar cells and photovoltaic modules are critically discussed. The most common substrates, the constituent layers and their interaction, the interfaces and the different “tricks” commonly used for obtaining highly efficient devices will be analyzed. A realistic industrial production process will be analytically described.

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