Eco-friendly synthesis and stability analysis of CsPbBr3​ and poly(methyl methacrylate)-CsPbBr3​ films.

Abstract

This study presents an eco-friendly mechanochemical (MC) synthesis of cesium lead bromide (CsPbBr3), eliminating the need of organic solvents and high temperatures. The synthesized CsPbBr3 powder is used to fabricate poly(methyl methacrylate) (PMMA)-CsPbBr3 films and CsPbBr3 nanocrystals (NCs). The photoluminescence (PL) peaks of the emission light are centered at 541 nm, 538 nm, and 514 nm for the CsPbBr3 powder, PMMA-CsPbBr3 films, and CsPbBr3 NCs, respectively, correlating with crystal sizes of 0.96, 0.56, and 0.12 μm, respectively. The PL lifetime analysis reveals decay times (τ_1,τ_2) of (4.18, 20.08), (5.7, 46.99), and (5.81, 23.14) in the units (ns, ns) for the CsPbBr3 powder, PMMA-CsPbBr3 films, and CsPbBr3 NCs, respectively. The PLQY of the CsPbBr3 NCs in toluene is 61.3%. Thermal activation energies for thermal quenching are 217.48 meV (films) and 178.15 meV (powder), indicating improved thermal stability with the PMMA encapsulation. The analysis of the PL decay from water diffusion in the PMMA-CsPbBr3 films yields 1.70x10^-12 m2/s for the diffusion coefficient of water, comparable to that for water diffusion in pure PMMA. This work demonstrates a scalable, sustainable strategy for CsPbBr3 synthesis and stability enhancement for optoelectronic applications.