Computer simulation of a-Si/c-Si heterojunction solar cell with high conversion efficiency

The p-type amorphous/ n-type crystalline silicon (P+ a-Si/N+ c-Si) heterojunction was simulated for developing the solar cells with high conversion efficiency and low cost. The characteristic of such cells with different work function of transparent conductive oxide (TCO) were calculated. The energy band structure, quantum efficiency and electric field are analyzed in detail to understand the mechanism of the heterojunction cell. Our results show that the a-Si/c-Si heterojunction is hypersensitive to the TCO work function, and the TCO work function should be large enough in order to achieve high conversion efficiency for P+ a-Si:H/N+ c-Si solar cell. With the optimized parameters set, the P+ a-Si:H/N+ c-Si solar cell reaches a high efficiency ({\eta}) up to 21.849% (FF: 0.866, VOC: 0.861 V, JSC: 29.32 mA/cm2).