Highly flexible, green luminescent down converting and hydrophobic 0-D cesium lead bromide (Cs4PbBr6)/ poly (vinylidene difluoride) polymer nanocomposites for photonics and display applications

Abstract

Halide perovskite materials have emerged as a promising new research topic in recent years, with potential applications in solar cells and optoelectronic devices, among others. These materials have significant limitations, including instability to water, heat, UV radiation, and light, limiting their research to the lab scale only. Encapsulation of perovskite with polymers is a solution for addressing the shortcoming of stability. This study illustrates the synthesis of zero-dimensional cesium lead bromide (Cs4PbBr6), as well as its poly (vinylidene difluoride) (PVDF) nanocomposites, optical, morphological, cell properties and increased stability towards the environmental stress. Different concentrations of synthesized perovskite was encapsulated in PVDF, namely 0.0, 0.5, 1.0, 1.5 and 2.0 wt/wt%. The UV–Visible spectral result depicts that the strong absorbance band ranges from 280 to 320 nm confirms the formation of Cs4PbBr6. X- ray diffraction (XRD) reveals the existence Cs4PbBr6 and good interaction between the perovskite and polymer matrix. The size of prepared perovskite is in nano scale and with high phase purity with rhombohedral unit cell with are depicted by using high-resolution transmission electron microscope (HR-TEM), selected area electron diffraction (SAED). The nanocomposites exhibit emission from 490 to 520 nm, and 2 wt/wt% of perovskite in PVDF exhibits the highest emission intensity analyzed using photoluminescence (PL) spectral results which is excited at 370 nm. PL lifetime decay measurements of the fabricated PVDF perovskite nanocomposites shows 34.744 ns for 2 % Cs4PbBr6/PVDF nanocomposites due to delayed exciton radiative recombination which infers that the fabricated nanocomposites finds potential application in the arena of photonics, UV-radiations blockers, and LEDs.