Color-tunable stable quasi-2D hybrid metal halide perovskites: synthesis, characterization, and optical analysis

Metal halide perovskites show remarkable optical properties and useful applications in optoelectronic devices. However, the instability of three-dimensional (3D) metal halide perovskites limits their applications, leading to the emergence of more stable two-dimensional (2D) metal halide perovskites. Herein, we present a facile synthesis of the 2D hybrid metal halide perovskite (EDA)(MA)(n-1)PbnBr3n+1 (EDA: ethylene diammonium, MA: methylammonium), where n = 1-6, and MAPbBr(3) perovskite layers using an anti-solvent co-precipitation technique. The synthesized materials exhibited tunable optical properties, and the color emissions of pure EDAPbBr4 and (EDA)(MA)(2)Pb3Br(10) perovskites were successfully tailored by altering halide anion layers. The band gap decreases as the value of n in the (EDA)(MA)(n-1)PbnBr3n+1 compound increases from 1 to 6. The as-prepared materials were characterized using X-ray diffraction (XRD) technique, Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), photoluminescence spectroscopy (PL), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDX). Finally, the stability of the 2D hybrid metal halide perovskite structures was evaluated under ambient conditions over different periods. Their tunable color emission was investigated and robust fluorescence was observed after 55 days. Thus, this study provides valuable insights into the synthesis and characterization of 2D hybrid metal halide perovskites for tunable color emission, highlighting their potential for use in various optoelectronic applications.