Theoretical exploration of high VOC in Cu2SnS3 thin film solar cells towards high efficiency

This article manifests the outstanding performance of copper-tin-sulphide (Cu2SnS3)-based doubleheterojunction (DH) photovoltaic cell. The n-type ZnSe as window and the p+-type CGS (CuGaSe2) as back surface field (BSF) layer have been used for the p-type Cu2SnS3 base layer. The SCAPS-1D simulator is used for the simulation of this photovoltaic cell and demonstrating the effects of each layer. The n-ZnSe/p-Cu2SnS3 heterojunction has displayed a power conversion efficiency (PCE) of 17.69 % with JSC = 32.39 mA/cm2, VOC = 0.60 V, and FF = 80.58 %, when functioning alone. An enrichment of PCE to 38.14 % has been observed, owing to the addition of CGS as a BSF layer in the proposed structure. The VOC also develops enormously to 1.22 V in dual-heterojunctions, which boosts the PCE. The effective band alignment between ZnSe/Cu2SnS3 and Cu2SnS3/CuGaSe2 interfaces produces greater built-in potential that is liable to generate high VOC. The built-in potential of the device is 1.54 V according to the C-V study. These outcomes imply that the n-ZnSe/p-Cu2SnS3/ p+-CGS device would be a viable alternative for harvesting solar energy in the era of thin film solar cells.