Solution-processed lead-free cesium titanium halide perovskites and their structural and optical characteristics

Abstract

Abstract Two primary challenges impede the extensive utilization of organic-inorganic lead halide perovskites: instability and potential risk of lead contamination. This paper describes an easy and effective solution-phase method for synthesizing lead-free Cs2TiI6 perovskites using inverse temperature crystallization. The perovskite precursor was deposited on glass substrates using various methods. The Cs2TiI6 films exhibit a cubic structure with a lattice parameter of 11.57 Å. The drop-cast thin film exhibited strong and broad absorption in the visible spectrum, indicating that Cs2TiI6 possesses notable optical properties. The optical energy gap calculated for both direct and indirect is 1.68 eV and 1.65 eV, respectively). The refractive index and optical conductivity demonstrate that Cs2TiI6 is an excellent optical absorber for photodevices. This study offers valuable perspectives for the advancement of lead-free double perovskites.