Performance enhancement of Sb2Se3 solar cell with IGZO and n-ZnO as electron transport layers

A prototype of an antimony (III) selenide (Sb₂Se₃) solar cell with different electron transport layers (ETLs) was simulated using the Solar Cell Capacitance Simulator (SCAPS) software. The impact of two individual ETLs – namely, indium gallium zinc oxide (IGZO) and n-type zinc oxide (n-ZnO) – was analyzed, and it was found out that n-ZnO was best for the ETL. The n-ZnO, antimony (III) selenide and Indium gallium zinc oxide (IGZO) layers in the newly proposed structure have respective thicknesses of 50, 300 and 20 nm. To achieve the optimum performance of this prototype, the acceptor concentration of copper (II) oxide is taken as 10¹⁸ cm⁻² and the donor concentration of n-ZnO is taken as 10²⁰ cm⁻². The defect densities at antimony (III) selenide and antimony (III) selenide/n-ZnO are taken as 10¹³ and 10¹⁰ cm⁻², respectively. They play a crucial part in device performance. With the optimized structure, a maximum power conversion efficiency of up to 31.72% (V _OC = 1.148 V, J _SC = 48.30 mA/cm² and fill factor = 88.50%) is obtained with n-ZnO as the ETL. For effective results, the defect densities at both interfaces are taken as 10⁹ cm⁻², and maximum efficiency is achieved. Numerical analysis of the proposed structure and study of various parameters such as thickness variation at the absorber layer, series resistance and temperature variation, defect density, metal function and interface density variation were done.