Halide perovskite and polymer composite film for bright light emitting devices

Abstract

Stability is the primary hindrance for the application of halide perovskite material in light emitting device, solar cell and other devices. In this work, halide perovskite and polymer composite film has been prepared for stable and bright light emitting devices. Pure-phase Cs₄PbBr₆ crystals have been synthesized, their photoluminescence (PL) properties and fluorescence lifetimes were investigated. The Cs₄PbBr₆ crystals exhibited high uniformity but underwent rapid photodegradation under light irradiation. To address this issue, we prepared bright light emitting devices using Cs₄PbBr₆ crystals and polyethylene oxide (PEO) as the emission layer. The aim was to improve the optical and physical properties of halide perovskites, such as photodegradation and stability. PEO, with its excellent film-forming ability, created a uniform and dense film on the halide perovskite surface, filling microscopic defects and providing a protective barrier. FTIR, morphology, and PL analyses confirmed the protective role of the halide perovskite and polymer composite film. The composite film light emitting devices demonstrated improved stability and higher PL brightness, with a peak brightness approaching 3×10⁸ cd/m², which was approximately 75% higher than the pure halide perovskite devices.