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

This study presents an eco-friendly mechanochemical 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 PL quantum yield 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 intensity decay from water diffusion in the PMMA-CsPbBr₃ films yields 1.70 × 10⁻¹² m² s⁻¹ 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.