The Impact of the Micro-Structure within Passivated Layers on the Performance of the a-Si:H/c-Si Heterojunction Solar Cells

Abstract

This study investigated the correlation between the degree of disorder of the post-hydrogen plasma treatment (HPT) of the intrinsic hydrogenated amorphous silicon (a-Si:H(i)) and the device characteristics of the a-Si:H/c-Si heterojunction (HJ) solar cells. The reduction in the degree of disorder helps to improve interface defects and to enhance the effective carrier lifetime of the a-Si:H/c-Si heterojunction. The highest effective minority carrier lifetime of 2.08 ms was observed in the film with the lowest degree of disorder of 2.03. The devices constructed with HPT a-Si:H(i) having a lower degree of disorder demonstrated higher device performance in terms of open-circuit voltage (Voc), fill factor (FF), and subsequent conversion efficiency. An a-Si:H(i) with a lower degree of disorder (2.03) resulted in a higher Voc of 728 mV and FF of 72.33% and achieved a conversion efficiency of up to 20.84% for the a-Si:H/c-Si HJ silicon solar cell.