Metal-Doped perovskite oxide Ba(1-x)Sr(x)TiO3 as electron transport layer for enhanced photovoltaic performance: An FDTD study

•Novel Sr-doped BaTiO3 ETL enhances perovskite solar cell performance beyond traditional TiO2 layers.•BST-incorporated PSCs achieve 16.32% efficiency, with potential to reach 28.65% in optimized devices.•FDTD simulations reveal BST's superior optical and electrical properties compared to BTO-based cells.•Findings advance interfacial engineering in PSCs, promising significant improvements in photovoltaic technology. This work investigates the potential of BaTiO3 (BTO) and Sr-doped BaTiO3 (BST) as electron transport layers (ETL) in perovskite solar cells (PSCs) through Finite-Difference Time-Domain (FDTD) simulations. A comprehensive analysis was conducted to optimize the thickness of each layer in the PSC structure, with the aim of enhancing the photovoltaic performance and stability. Results indicate that BST-based PSCs exhibit superior optical and electronic properties compared to BTO-based PSCs, achieving higher ultimate efficiency (28.65 %) and power conversion efficiency (16.32 %). This improvement is attributed to better band alignment and higher electron mobility in BST, which enhances charge separation and reduces recombination losses. Optical analysis reveals that BST-based PSCs have a consistently higher spectral response across all wavelengths, indicating more effective light absorption and conversion into electrical current. The external quantum efficiency (EQE) of BST-based PSCs is consistently higher, resulting in an increase in Jsc of 16.87 mA/cm2 compared to 15.96 mA/cm2 for BTO-based cells. These findings highlight the potential of BST as a superior ETL material for high-performance PSCs, offering light management and charge-transport properties improved compared to those of conventional BTO-based ETLs.