Strain-engineered Ba3SbBr3 perovskite for high-efficiency photovoltaic applications: Insights from DFT and SCAPS-1D

This study presents a comprehensive first-principles density functional theory (FP-DFT) and SCAPS-1D investigation of the lead-free inorganic halide perovskite Ba 3 SbBr 3 to assess its strain-tunable properties for photovoltaic performance and optoelectronic applications. The structural stability of the perovskite is confirmed by the enthalpy of formation energy under various strain conditions. The unstrained structure exhibits a direct bandgap of 1.1908 eV (PBE), 1.6093 eV (HSE06), and 1.05 eV (PBE+SOC) at the Γ point. Bandgap tuning via strain is observed: compressive strain results in narrowing of the bandgap, while tensile strain leads to widening. Dynamic stability is validated across all applied strain conditions through phonon dispersion calculation. Mechanical analysis reveals a notable transition from brittle to ductile behavior when the material is subjected to compression. Optical analyses reveal strong light absorption with low energy loss in the visible spectrum. Simulations of devices using Ba 3 SbBr 3 and SnS 2 as the electron transport layer (ETL) through the SCAPS-1D simulator demonstrate an impressive power conversion efficiency (PCE) of 31.54% under a strain of −4%. The research demonstrates that strain-engineered lead-free halide perovskite Ba 3 SbBr 3 is a promising material for efficient solar cells and advanced optoelectronic devices.