| Thin film silicon solar cells have a lot of advantage than the crystalline silicon solar cells, such as simple fabrication, less consumption. Meanwhile, they can be deposited on cheap substrates for large-scale production. Furthermore, it's easy to combine thin film silicon solar cells with the building materials to compose the Building Integrated Photo- voltaic (BIPV) system. So, the thin film silicon solar cell has drawn great attention of the governments and research institutes both at home and abroad.This paper reports the performances of thin film silicon solar cells were simulated by Microelectronics and Photonic Structures (AMPS) computer model developed at Penn State University. We studied the influence of window materials for amorphous silicon film solar cells, also the optimal design of the intrinsic layer thickness is obtained. Then developed a mathematical physical modeling for graded band-gap microcrystalline silicon solar cells, and simulated graded band-gap microcrystalline silicon solar cells. Finally, a-Si/μc-Si tandem solar cells optimized design of cell structure and fabrication parameter are studyed. The major research can be briefed as follows:(1) The influences of the window materials on the performance of p-i-n amorphouss silicon solar cells are simulated. First, the p-type hydrogenated microcrystalline silicon (p-μc-Si:H) window layer are simulated. When the thickness ofμc-Si:H p layer is 10nm, the mobility band gap (Eμ) is 1.6eV, the performances of solar cells were optimum, 13.096% of a conversion efficiency has been achieved. The performances of solar cells improve markedly as inserting an i-a-SiC:H buffer layer, 13.232% of a conversion efficiency has been achieved. Then, the p-type hydrogenated amorphous silicon carbide (p-a-SiC:H) window layer are simulated. When the thickness of a-SiC:H p layer is 10nm, the doping concentration is 1019cm2 , the better performances of solar cells were obtained, and 11.233% of a conversion efficiency has been achieved. Finally, The influences of the thickness of i-layer on the performance of p-i-n amorphous silicon solar cells with p-μc-Si:H window layer are simulated. That is, the thickness of i-layer is about 400nm, and the conversion efficiency of cells is 13.251%.(2) Related to the use of experimental data, using the relationship between mobility gap and crystalline volume fraction of microcrystalline silicon, on total photo-generated carriers generation rate and photo-generated carriers recombination of intrinsic layer graded band-gap microcrystalline silicon solar cells, and comparison for general solar cells are carried out. On the one hand, the structure of graded band-gap increase of microcrystalline silicon i-layer into the active layer as a light absorption; On the other hand, there are defects and recombination centers between all graded layers, and collection of carriers are influenced. For the increasing band gap-typeμc-Si: H thin-film solar cells, when i-layer the total thickness of 1.2μm, 14.843% of conversion efficiency has been achieved.(3) The structure of a-Si:H/μc-Si:H tandem solar cells was designed, and the thickness of i-layer of top and bottom cell are optimized. When the thickness of the intrinsic layer of top and bottom cells are 90nm and 1.5μm, optimal current-matching was obtained. Tunneling recombination junctions adopt microcrystalline silicon. We studied the influence of the thickness of tunneling recombination junctions with n/p and n/i/p structure, the band gap , the defect densities and the doping concentration etc. on the optoelectric characteristics of the solar cells. When the thickness of n/p tunneling recombination junctions is 25nm, the mobility band gap (Eμ) is 1.4eV, the doping concentration is 5×1018cm-3, the defect densities is 3×1018cm-3, and the conversion efficiency of cells is 10.870%. When the i-μc-Si:H layer thickness of n/i/p tunneling recombination junctions is 5nm, the defect densities is 3×1019cm-3, 12.086% of a conversion efficiency has been achieved.
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