Maneuvering investigation of theoretical and experimental parameters for Al-doped Cu (In, Ga) Se2 thin film solar cells with and without a back surface field layer

Abstract

Aluminum-doped copper indium gallium selenide/sulfide (CIGAS) is a favorable absorber material for solar cell applications; however, the number of reports on CIGAS solar cells currently remains limited. In this study, we therefore employed SCAPS-1D software for the theoretical modeling of CIGAS thin film solar cells and investigated the effect of material properties and device configurations on solar cell photovoltaic (PV) parameters. Initially, key parameters such as thickness and charge carrier concentrations of each layer used in CIGAS PV devices were studied and optimized to obtain suitable conditions for high device performance. The impact of the various buffer window layers (BWL)—such as CdS, In₂S₃, ZnS, ZnSe, In₂Se₃, V₂O₅, ZnO, and MgZnO—as well as the back surface field (BSF) layers, including Sb₂Se₃, AlSb, CuGaSe₂, SnS, BaSi₂, MoS₂, MoSe₂, p-Si, CuS, and WSe₂, was systematically tested to determine a CIGAS solar cell configuration with greater efficiency. After meticulous optimization, CdS and Sb₂Se₃ materials were selected as the best BWL and BSF layers for the CIGAS device configuration, respectively, demonstrating a maximum power conversion efficiency (PCE) of 32.2% compared to other chosen materials. Finally, an experimentally obtained CIGAS absorber and CdS buffer material properties were introduced into optimized conditions with and without a BSF layer to further analyze their influence on solar cell performance. This also confirmed that the BSF layer significantly boosts device efficiency compared to the conventional CIGAS device.