An innovative strategy: ultra-stable alkaline earth modified CsPbBr3 quantum dots glass was prepared by washing-heat cycle for high definition backlight display

Abstract

All-inorganic perovskite quantum dots (QDs) as high-quality materials for backlight display are still limited by their own low stability. Herein, the crystallization of CsPbBr3 (CPB) QDs in a glass matrix was promoted by modifying the glass network structure with alkaline earth metals (Mg, Ca, Sr, Ba). What's more, a washing-heat treatment cycle strategy was used to optimize the best-modified sample (CPB–Mg). Among them, CPB-12Mg (add 12% MgO) showed a high photoluminescence quantum yield (PLQY = 62%) after the cycling process. More surprisingly, the six-step washing-heat treated-sample (CPB–12Mg-6) showed excellent stability. When CPB-12Mg-6 was irradiated for 240 h at 60°C, 90% relative humidity (RH), and 880 W/m2 blue light power (60°C, 90% RH, 880 W/m2), the original 90% fluorescence emission could still be maintained. Subsequently, a series of CPB-12Mg-6/CsPbBr1.5I1.5@PS light conversion films were prepared by the master batch blending method. The backlight conversion film for liquid crystal display (LCD) achieves a wide color gamut that covers 126% of the NTSC 1953 and 93.6% of the Rec.2020 standard. This innovative washing-heat treatment cycle strategy provides a new idea for improving the stability of perovskite quantum dots.