Efficient Luminescence from CsPbBr₃ Nanoparticles Embedded in Cs₄PbBr₆

Abstract

Cs₄PbBr₆ is regarded as an outstanding luminescent\nmaterial with good thermal stability and optical performance. However,\nthe mechanism of green emission from Cs₄PbBr₆ has been controversial. Here we show that isolated CsPbBr₃ nanoparticles embedded within a Cs₄PbBr₆ matrix\ngive rise to a “normal” green luminescence while superfluorescence\nat longer wavelengths is suppressed. High-resolution transmission\nelectron microscopy shows that the embedded CsPbBr₃ nanoparticles\nare around 3.8 nm in diameter and are well-separated from each other,\nperhaps by a strain-driven mechanism. This mechanism may enable other\nefficient luminescent composites to be developed by embedding optically\nactive nanoparticles epitaxially within inert host lattices.