Performance enhancement of Sb2Se3 solar cell using a back surface field layer: A numerical simulation approach

Abstract

In the present work, antimony selenide (Sb2Se3)-based solar cell with a back surface field (BSF) layer has been designed and studied. The purpose of this research is to improve the performance of the Sb2Se3-based solar cell by introducing low-cost and widely available barium silicide (BaSi2) material as the BSF layer into the basic Sb2Se3-based heterojunction solar structure. A comparative study on the performance of the conventional Sb2Se3 solar cell structure consisting of Al/FTO/CdS/Sb2Se3/Mo and the proposed structure of Al/FTO/CdS/Sb2Se3/BaSi2/Mo is made. The photovoltaic parameters such as open circuit voltage, short-circuit current density, fill-factor, power conversion efficiency, and quantum efficiency of heterojunction structures are analyzed intensively by using the Solar Cell Capacitance Simulator in One Dimension (SCAPS-1D) program. To optimize the device, the thickness of Sb2Se3 absorber layer is varied from 0.1 to 2 μm. In addition, the effects of acceptor ion and bulk defect densities in Sb2Se3 absorber layer, interface defect density of buffer/absorber and absorber/BSF, back surface recombination velocity, operating temperature, and cell resistances on the overall performances are investigated. The thicknesses of BaSi2 BSF and Sb2Se3 absorber layers are optimized to be 0.3 μm and 1 μm, respectively. The efficiency of the proposed solar structure with a thin 1 μm Sb2Se3 absorber layer is obtained to be 29.35%. The simulation results lead to suggest that the BaSi2 material as a BSF layer would be effective to fabricate low cost and high-efficient Sb2Se3-based thin-film solar cells.