Abstract:The performance of TCO/a-SiH(n)/a-SiH(i)/c-Si(p)/aSiH(p+)/Ag heterojunction solar cells on p-type Silicon substrates was simulated by Afors-het software. Optimal structural parameters of thickness, band gap, doping concentration and interface states density were obtained by the results of software optimization and theoretical analysis. The results indicate that well-performed heterojunction solar cells can be designed by using thin and high doping window layer, passivating the defect states of heterojunction interface with intrinsic layer, and making full use of the mirror effect of back surface field. The optimum performance parameters are Voc=678.9mV,Jsc=38.33mA/cm2,FF=84.05%,η=21.87%.