Numerical simulation of CIGS, CISSe and CZTS-based solar cells with In2S3 as buffer layer and Au as back contact using SCAPS 1D

Abstract

A solar cell capacitance simulator named SCAPS 1D was used in the prediction study of Cu(In, Ga)Se2 (CIGS), CuIn(S, Se)2 (CISSe) and Cu2ZnSnS4 (CZTS) based solar cells where indium sulphide (In2S3), fluorine-doped tin oxide/FTO (SnO2:F) and gold (Au) were used as buffer layer, window layer and back contact respectively. We investigated the effect of thickness, defect density and carrier density of the different absorber layers, thickness of the buffer layer and at 300 K temperature and standard illumination, the optimum devices revealed highest efficiencies of 18.08%, 22.50%, 16.94% for CIGS, CISSe, CZTS-based cells respectively. Effect of operating temperature, wavelength of light and electron affinity of the buffer layer on the optimized solar cell performance was also observed. Moreover, simulations were run with tin (Sn) doped In2S3 buffer layer to see the change in electrical measurements in comparison with undoped condition and also, investigation was carried out by replacing In2S3 buffer layer with traditional cadmium sulphide (CdS) buffer layer with the aim of comparing their respective output parameters. All these simulation results will provide some vital guidelines for fabricating higher efficiency solar cells.