Design And Behavioral Simulation Of A-Si:H/c-Si Heterojunction Solar Cells

Under the current situation of energy crises and environment pollution issues, the solar cell has obvious advantages. However, the higher cost and lower energy conversion efficiency of solar cell block its development. Due to the high energy conversion efficiency and low cost properties, the amorphous silicon/silicon heterojunction has been widely studied in recent years. A heterojunction solar cell with gradient band gap used in the a-Si:H(n) window layer is designed in this thesis in order to improve the performances of the cell. Some parameters that affect the properties of cell have been simulated by AFORS-HET software. The main contents of the thesis is as follows:Firstly, a-Si:H(n)/a-Si:H(i)/c-Si(p) heterojunction solar cell with a intrinsic layer has been designed. The influence of the thickness of the window layer, the intrinsic layer, and the absorption layer, the doping concentration and the band gap to the property of the solar cell were simulated by AFORS-HET software. The optimal parameter values were found.And it focused on the influence of the density of the density of interfacial state, the conduction band and the valence band tail; it also be used to analyse the influence mechanism.Secondly, a-Si:H(n)/a-Si:H(i)/c-Si(p)/a-Si:H(p+) heterojunction with a-Si:H(p+) as back surface field has been designed, the optimal parameter values of the thickness and doping concentration of back surface field were found, and back surface field has a antinomy effect to carriers.Finally, it designed the solar cell with the window layer of gradient band gap. Then the AFORS-HET software was used to simulate how the doping gradient affect cell performance. When the doping contene in emission layer was constant; and the influence of different doping content to the cell performance when doping gradient unchanged. It found that the constant one is good for the improvement of spectral response. At last, the gradient doping cell with back surface field was designed.The simulation results of this thesis have provided a certain basis to other cell research, has a certain theoretical and practical significance.