Femtosecond laser annealing of fluorine-doped tin oxide films towards high-performance perovskite photovoltaics

Abstract

Transparent conductive electrodes are important components of perovskite solar cells (PSCs), and their carrier transport capabilities directly affect the power conversion efficiency (PCE) of PSCs. Despite the excellent optical and electrical properties of commercialized fluorine-doped tin oxide (FTO), its poor wettability reduces the quality of the electron transporting layer (ETL) thin film, thereby affecting the charge carrier transfer efficiency in PSCs. To further optimize the performance of FTO films, we propose a femtosecond laser annealing (fs-LA) technique to successfully allow OH⁻ ions to replace F⁻ ions on the surface, thereby improving optoelectronic performance and enhancing surface hydrophilicity. These enhancements effectively decrease non-radiative recombination at the interface and enhance carrier transport capabilities. PSCs based on FTO films treated by the fs-LA technique achieve a PCE of 22.33%. This result provides a reference for the performance optimization of transparent conductive oxide (TCO) films.