Novel CsPbBr1.5I1.5@SrHAp single-phase white-light emitting phosphors: Facile synthesis, formation process, enhanced stability, and color-tunable luminescence

Abstract

A variety of novel CsPbBr1.5I1.5@SrHAp nanocomposites have been fabricated by a facile one-pot hot injection method for the first time. An electrostatic interaction mechanism has been proposed to realize the in-situ growth of CsPbBr1.5I1.5 perovskite quantum dots (PQDs) on SrHAp [strontium hydroxyphosphate, Sr5(PO4)3OH] nanorods with negatively charged surfaces, which have been proved by the XRD, XPS, TEM, FT-IR, and density functional theory (DFT). The incorporation of SrHAp matrix for CsPbBr1.5I1.5 not only greatly enhances the thermal and spectral stability but also increases the emission intensity of the CsPbBr1.5I1.5 PQDs. More importantly, the fascinating color-tunable luminescence performance from blue through white and eventually toward yellow light can be realized in a single phase by simply changing the amounts of SrHAp matrix or excitation wavelengths. Thus, the CsPbBr1.5I1.5@SrHAp single-phase white light emitting phosphor can be obtained with excellent chromaticity coordinate (x, y) and CCT in the warm white region [(0.328, 0.340), 5698 K], which is close to the daily use of pure white light. The as-prepared LED device can exhibit dazzling white light emission by integrating CsPbBr1.5I1.5@SrHAp nanocomposite into a 365 nm UV LED chip, which indicates that the as-obtained CsPbBr1.5I1.5@SrHAp single-phase white emitting phosphor could be regarded as potential candidates for WLEDs.