High-efficiency GaInP solar cells: DFT and SCAPS-1D guided design and optimization

Abstract In the pursuit of more efficient and thermally stable solar cells, this study takes a targeted approach to optimizing GaInP-based architectures. Five electron transport layers (ETLs) and twelve-hole transport layers (HTLs) were systematically evaluated using SCAPS-1D simulations to fine-tune device parameters and Density Functional Theory (DFT) calculations to probe the electronic and optical behaviour of the materials involved. Among sixty unique configurations, a device employing TiO 2 as the ETL, Cu 2 O as the HTL, and GaInP as the light-absorbing material is chosen. This combination demonstrated optimum performance, achieving a power conversion efficiency (PCE) of 28.4%, a fill factor (FF) of 88.2%, short-circuit current density (J sc ) of 17.6 mA cm −2 , and an open-circuit voltage (V oc ) of 1.8 V. More importantly, by advancing a lead-free, thermally stable architecture, the study delivers a groundbreaking pathway for environmentally safe, high-efficiency photovoltaics. Through its dual-framework of theoretical modelling and simulation, these results highlight GaInP solar cells as promising candidates for tandem photovoltaics, emerging indoor IoT energy-harvesting applications and space-based power systems.