A comprehensive strategy for enhancing stability and luminescence of CsPbBr3 nanoparticles via low dose electron-beam treatment

Abstract

Lead-halide perovskite (LHP) nanoparticles (NPs), such as CsPbBr₃, exhibit exceptional luminescent properties, making them promising candidates for optoelectronic applications. However, maintaining their stability on solid substrates is challenging due to light and heat-induced degradation, even without water and oxygen. Although various post-processing methods aim to enhance stability, achieving this without compromising luminescence is difficult yet critical for practical devices. This study investigates the stability of monolayer CsPbBr₃ NPs under simulated light and thermal stress, identifying accelerated post-growth processes as the main instability source. To address this, we evaluated surface ligand post-treatments, including ultraviolet-ozone, plasma, and electron beam (e-beam) irradiation. Among these, low-dose e-beam irradiation proved most effective, significantly enhancing both luminescence and structural stability. Using correlative cathodoluminescence electron microscopy (CCLEM) and transmission electron microscopy (TEM), we established a dose-dependent relationship where optimal e-beam doses suppress nanoparticle growth and boost luminescence, while excessive doses degrade luminescence. Mechanistically, e-beam treatment forms a stable carbonaceous encapsulation layer on nanoparticle surfaces, preventing inter-particle contact and passivating surface impurities without causing significant structural damage. These findings demonstrate that low-dose e-beam irradiation is a versatile tool for tuning CsPbBr₃ NPs properties, offering new pathways to optimize the stability and performance of perovskite-based materials in advanced optoelectronic applications.