Suppression of Thermal Quenching for CsPbX3 (X = Cl, Br, and I) Quantum Dots via the Hollow Structure of SrTiO3 and Light-Emitting Diode Applications.

Abstract

All-inorganic perovskite quantum dots (PQDs, CsPbX3, X = Cl, Br, and I) show outstanding application prospects in the field of photoelectric devices. In recent years, the development of PQDs has greatly improved their stability to water, oxygen, and light. However, thermal quenching of PQDs greatly limits their practical application. Herein, we embed PQDs into ATiO3 (A = Ca, Ba, and Sr) of three different mesoporous spherical structures to explore the effect on thermal quenching of PQDs. Because of the unique mesoporous hollow microsphere structure and low thermal conductivity of SrTiO3, it can effectively block the heat transfer and improve the thermal quenching of PQDs. The photoluminescence (PL) intensity of CsPbBr3@SrTiO3 composites is 72.6% of the initial intensity after heating to 120 °C. Moreover, the PL intensity of CsPbBr3@SrTiO3 composites remains about 80% of the initial value even when stored in air for 20 days or irradiated by 365 nm UV light for 48 h. A neutral white light-emitting diode is assembled by a blue chip, CsPbBr3@SrTiO3 composites, and red phosphor of K2SiF6:Mn4+, which has a color temperature of 5389 K and a color gamut covered 133% of National Television Standards Committee (NTSC).