Enhanced efficiency of thin-film solar cells using AgInSe₂ back surface field layer: a SCAPS-1D numerical study

Abstract

This study investigates the role of AgInSe₂ (AISe) as a back surface field (BSF) layer in enhancing thin-film photovoltaic (PV) devices with three absorber materials: Cu₂ZnSnS₄ (CZTS), Cu(In,Ga)Se₂ (CIGS), and CuInTe₂ (CIT). Device simulations using SCAPS-1D incorporated a CdS window layer and an AISe BSF layer. Baseline efficiencies without AISe were 17.43% (CZTS), 22.43% (CIGS), and 24.22% (CIT). Introducing AISe significantly boosted power conversion efficiency to 21.83%, 29.19%, and 31.40%, respectively. These improvements stem from enhanced built-in potential and reduced carrier recombination, resulting in higher open-circuit voltage (VOC), short-circuit current density (JSC), and fill factor (FF). Capacitance–voltage analysis and quantum efficiency (QE) profiles further validated the performance gains. Parametric investigations of absorber and BSF properties—thickness, doping, defect density, temperature, and resistance—highlighted their influence on device output. Overall, AISe emerges as a promising BSF material for next-generation thin-film solar cells.