Stability enhancement and pronounced three-photon absorption in SrCl2-doped FAPbBr3 nano crystals

Abstract

Size-dependent perovskite nanocrystals (PNCs) have manifested tremendous improvement in nonlinear optical (NLO) studies owing to their remarkable optical and electrical properties. However, the industrialization of these materials has been circumscribed by their toxicity and instability. Attractive candidates explored to date in the quest for frontline NLO properties include organic–inorganic hybrid perovskites (OIHPs). Given the remarkable stability of the formamidinium cation (HC(NH₂)₂⁺ = FA⁺)) over the methylammonium cation (MA⁺) in hybrid perovskites, FAPbBr₃ was chosen as a prototype to investigate its interactions with Sr²⁺ ions. Intriguingly, SrCl₂-doped FAPbBr₃ PNCs showed enhanced three-photon absorption (3PA) comparable/superior to some recently reported PNCs. This work paves the way for developing more stable, less toxic organic–inorganic hybrid perovskite (OIHP) PNCs for optoelectronic applications.