Simulation of High-Efficiency Crystalline Silicon Solar Cells With Homo–Hetero Junctions

A novel solar cell structure consisting of both homojunction and heterojunction (homo-hetero junctions), which possesses a potential to realize high photoelectric conversion efficiency, is investigated by the numerical simulation tool AFORS-HET. We demonstrate that the homo-hetero junctions solar cell has a higher fill factor than the solar cell with heterojunction with intrinsic thin layer (HIT), due to the reduced series resistance, which results in a better conversion efficiency, whereas their interfacial density of states (DOS) values are identical. Through a detailed study of the effect of inserting a homojunction, we find that the field-effect passivation can adequately explain the interesting behaviors that the open-circuit voltage increases and the emitter saturation current density declines when increasing the doping concentration in the P-type crystalline silicon layer. In addition, as compared with the HIT solar cell, the homo-hetero junctions solar cell is less sensitive to the DOS due to the field-effect passivation, leading to a comparable open-circuit voltage even if its total interfacial DOS is 10 times higher.