Design and Growth of Band-GAP Graded a-SiGe:H Solar Cells

1995 ◽  
Vol 377 ◽  
Author(s):  
K. Vasanth ◽  
A. Payne ◽  
B. Crone ◽  
S. Sherman ◽  
M. Jakubowski ◽  
...  
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Band Gap ◽  
Triple Junction ◽  
Cell Parameter ◽  
Red Light ◽  
Experimental Results ◽  
Buffer Layers ◽  
Silicon Solar Cells ◽  
Device Design

ABSTRACTThe i-layers of the middle and bottom cells in stable triple-junction amorphous silicon solar cells are composed of a-SiGe:H alloys which are graded in composition to enhance performance. We compare modeling and experimental results for three i-layer band gap grading schemes to determine the optimal profile. We find a good correlation between model trends and measured device parameters for all grading schemes. This is encouraging for the use of the model in predictive device design. We find that the highest white and red light performance do not necessarily have the same cell parameter set. Modeling and experiment indicate that thin cells without band gap profile and with suitably designed p/i and n/i buffer layers, have the best red light performance.

Stable Solar Cells Prepared from Dichlorosilane

1998 ◽  
Vol 507 ◽  
Author(s):  
Y. Yamamoto ◽  
W. Futako ◽  
K. Fukutani ◽  
M. Hagino ◽  
T. Sugawara ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
Band Gap ◽  
Buffer Layers ◽  
Silicon Solar Cells ◽  
Hydrogen Dilution ◽  
Cell Structures ◽  
Reactive Plasma ◽  
Plasma Species

ABSTRACTAmorphous silicon films and solar cell i-layers were prepared from dichlorosilane(DCS) by ECR- and VHF-CVD. The hydrogen content, the chlorine content and the band gap could be controlled by varying argon and hydrogen dilution. The interaction of energetic and reactive plasma species with substrates and other previously deposited layers was studied. DCS, ECR-CVD causes darkening of TCO substrates even when buffer layers and/or doped layers were previously deposited by RF-CVD. Therefore n-i-p solar cell structures were prepared on NiCr and subsequent p-i-n solar cells were prepared with VHF-CVD which did not causeTCO reduction or other reactions in previously deposited amorphous layers. Preliminary results indicate that the VHF-CVD solar cells are at least as stable as standard amorphous silicon solar cells.

Optical and electrical modeling of thin-film silicon solar cells

2008 ◽  
Vol 23 (4) ◽  
pp. 889-898 ◽  
Author(s):  
M. Zeman ◽  
J. Krc
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
Triple Junction ◽  
Silicon Germanium ◽  
Buffer Layers ◽  
Silicon Solar Cells ◽  
Antireflective Coatings ◽  
Thin Film Silicon

This article focuses on the modeling and simulation of thin-film silicon solar cells to obtain increased efficiency. Computer simulations were used to study the performance limits of tandem and triple-junction, silicon-based solar cells. For the analysis, the optical simulator SunShine, which was developed at Ljubljana University, and the optoelectrical simulator ASA, which was developed at Delft University of Technology, were used. After calibration with realistic optical and electrical parameters, we used these simulators to study the scattering properties required, the absorption in nonactive layers, antireflective coatings, and the crucial role of the wavelength-selective intermediate reflector on the performance of the solar cells. Careful current matching was carried out to explore whether a high photocurrent [i.e., more than 15 mA/cm2 for a tandem hydrogenated amorphous silicon (a-Si:H)/hydrogenated microcrystalline silicon (μc-Si:H) solar cell and 11 mA/cm2 for a triple-junction a-Si:H/amorphous silicon germanium (a-SiGe:H)/μc-Si:H solar cell] could be obtained. In simulations, the extraction of the charge carriers, the open-circuit voltage, and the fill factor of these solar cells were improved by optimizing the electrical properties of the layers and the interfaces: a p-doped, a-SiC layer with a larger band gap (EG > 2 eV) and buffer layers at p/i interfaces were used. Simulations demonstrated that a-Si:H/μc-Si:H solar cells could be obtained with a conversion efficiency of 15% or higher, and triple-junction a-Si:H/a-SiGe:H/μc-Si:H solar cells with an efficiency of 17%.

Amorphous Silicon Solar Cells Techniques for Reactive Conditions

1999 ◽  
Vol 557 ◽  
Author(s):  
Satoshi Shimizu ◽  
Kojiro Okawa ◽  
Toshio Kamiya ◽  
C.M. Fortmann ◽  
Isamu Shimizu
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Vapor Deposition ◽  
Cyclotron Resonance ◽  
Electron Cyclotron Resonance ◽  
Chemical Vapor ◽  
Buffer Layers ◽  
Silicon Solar Cells ◽  
Doped Zno ◽  
Defect Densities

AbstractThe preparation of amorphous silicon films and solar cells using SiH2Cl2 source gas and electron cyclotron resonance assisted chemical vapor deposition (ECR-CVD) was investigated. By using buffer layers to protect previously deposited layers improved a-Si:H(Cl) solar cells were prepared and studied. The high quality a-Si:H(Cl) films used in this study exhibited low defect densities (~1015cm-3) and high stability under illumination even when the deposition rate was increased to ~15A/s. The solar cells were deposited in the n-i-p sequence. These solar cells achieved VOC values of ~ 0.89V and ~ 3.9% efficiency on Ga doped ZnO (GZO) coated specular substrate. The a-Si:H(C1) electron and hole μτ products were ~10-8cm2/V.

High Efficiency Thin Film Silicon Solar Cells

2013 ◽  
Vol 750-752 ◽  
pp. 970-973
Author(s):  
Chun Rong Xue ◽  
Xia Yun Sun
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Amorphous Silicon ◽  
Triple Junction ◽  
High Efficiency ◽  
Silicon Solar Cells ◽  
Cell Efficiency ◽  
High Efficiency Solar Cells ◽  
Alternative Material ◽  
Staebler Wronski Effect

High-efficiency solar cells based on amorphous silicon technology are designed. Multi-junction amorphous silicon solar cells are discussed, how these are made and how their performance can be understood and optimized. Although significant amount of work has been carried out in the last twenty-five years, the Staebler-Wronski effect has limited the development of a-Si:H solar cells. As an alternative material, nc-Si:H has attracted remarkable attention. Taking advantage of a lower degradation in nc-Si:H than a-Si:H and a-SiGe:H alloys, the light induced degradation in triple junction structures has been minimized by designing a bottom-cell-limited current mismatching, and obtained a stable active-area cell efficiency. All this has been investigated in this paper.

Converting sunlight into red light in fluorosilicate glass for amorphous silicon solar cells

2017 ◽  
Vol 183 ◽  
pp. 433-436 ◽  
Author(s):  
Chengguo Ming ◽  
Feng Song ◽  
Xiaobin Ren ◽  
Fengying Yuan ◽  
Yueting Qin ◽  
...  
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Red Light ◽  
Silicon Solar Cells

Amorphous Silicon-Germanium Alloy Solar Cells with Profiled Band Gaps

1989 ◽  
Vol 149 ◽  
Author(s):  
J. Yang ◽  
R. Ross ◽  
T. Glatfelter ◽  
R. Mohr ◽  
S. Guha
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Band Gap ◽  
Silicon Germanium ◽  
Collection Efficiency ◽  
Red Light ◽  
Light Illumination ◽  
Multiple Band ◽  
Amorphous Silicon Germanium ◽  
Conversion Efficiencies

ABSTRACTWe have studied the spectral dependence of various types of amorphous silicon-germanium (a-Si:Ge) alloy p-i-n solar cells in which the band gap of the intrinsic (i) layer is profiled between 1.4 and 1.7 eV. It is observed that the cell performance depends critically on the shape of the profile, especially for red-light illumination where the device output is found to vary by more than a factor of two. We have correlated the experimental data with optical absorption and dynamic internal collection efficiency (DICE) measurements. We have also fabricated two-cell tandem and three-cell triple devices by incorporating a-Si:Ge alloy with multiple band-gap profiles in the bottom cell and achieved 13.0% and 13.7% conversion efficiencies, respectively. These are the highest efficiency amorphous silicon-based alloy solar cells reported to date.

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