Formation of a photoactive quasi-2D formamidinium lead iodide perovskite in water

Abstract

There has been no report on the synthesis of fluorescent α-phase stabilized quasi-2D FAPbI3 [FA = CH(NH2)2] perovskite nanocrystals (NCs) in water. We report the top–down synthesis of fluorescent quasi-two dimensional (2D) α-FAPbI3 NCs in aqueous media by controlling the electronic states of lead and the NCs size of FAPbI3. The product was stable in ambient conditions for more than six months. We explored a detailed synthetic study, their emissive properties and phase stabilization mechanism corroborated by density functional theory (DFT) calculations. Single particle imaging and photoluminescence (PL) study of α-FAPbI3 NCs bear the signature of dual emission, which indicates the formation of self-trapped excited states. Our findings will pave the way to develop phase-stabilized hybrid perovskite NCs in water, beneficial for optoelectronic devices.