Unraveling the effects of a GeSe BSF layer on the performance of a CuInSe2 thin film solar cell: a computational analysis

Abstract

In this work, a dual-heterojunction (DH) thin film solar cell of notable efficiency has been designed and simulated where p-type CuInSe2 (CIS) has been employed as the base layer in combination with an n-type CdS window and a p + -type GeSe back surface field (BSF) layer. The influences of each layer have been revealed using the SCAPS-1D simulator. While the n-CdS/p-CIS single heterojunction (SH) structure acting alone has been found to be resulted with 24.86% of photoconversion efficiency (PCE) with the JSC = 42.80 mA/cm2, VOC = 0.70 V, and FF = 83.44%, an enhancement to PCE of 30.52% is observed with the corresponding JSC of 44.10 mA/cm2, VOC of 0.86 V, and FF of 80.30% owing to the addition of GeSe as BSF layer in the proposed structure with optimized parameters. Because of the enormous built-in potential of the CIS/GeSe interface, increased VOC mostly contributes to the efficiency enhancement. These findings suggest that the CIS absorber layer with GeSe BSF layer is a promising choice for solar energy harvesting in the near future.