Formamidinium-Based Quasi-2D Perovskite Nanoplates With Dimensionally Tuned Optical Properties

We report for the first time the synthesis of quasitwo-dimensional (2D) perovskite nanoplates by incorporating 2D TMA(2) PbBr4 (C-4 H-9 NH3, TMA) into formamidinium (FA) based 3D perovskite nanocrystals via the facile solution-processed method. In this way, we achieve morphology evolved quasi-2D perovskite TMA(2)(FA)(n-1) PbnBr3n+1. The steady-state photoluminescence is blueshifted as the perovskite is dimensionally tuned from 3D to 2D, which is normally attributed to the structure relaxation. The optical properties of quasi-2D perovskite nanoplates can also be achieved by tuning the acidity of the reaction precursor. The proposed configuration and growth mechanism of quasi 2D TMA(2)(FA)(n-1) Pb(n )Br(3n+1 )perovskite with different n values has been further confirmed by Raman spectroscopy. This study opens up opportunities for fundamental research on the synthesis and characterization of quasi-2D perovskite nanoplates and introduces a new family of quasi-2D solution-processed perovskites for optoelectronic devices.