In order to theoretically improve the conversion efficiency of amorphous silicon solar cells, this article uses AMPS (Analysis of Microelectronic and Photonic Structures) mode was used to module the a-Si solar cells with a structure of TCO/p-a-SiC∶H/i-a-Si∶H/n-a-Si∶H/metal. The intrinsic layer thickness, band gap, doping concentration, defect density of states and other factors were analyzed and compared on the performance of solar cells. The simulation results are as follows: when the work function equals to 5.2 eV, band gap is about 1.8 eV, the intrinsic layer thickness is 265 nm, and amorphous silicon solar cell′s conversion efficiency can be 9.855%, which is almost 2% more than the average conversion efficiency of amorphous silicon solar cells.