CsPbX₃@Glass (X = Cl, Br, I) Nanocomposites with Whole‐Family High Absorption Efficiency above 75% for Backlit Display

Abstract In situ growth of CsPbX 3 (X = Cl, Br, I) perovskite quantum dots (PeQDs) in inorganic glass can address their stability issue for wide‐color‐gamut full‐color backlit displays. However, most of the reported CsPbX 3 precipitated in glass are limited by low absorption and low external quantum efficiency (EQE). This work demonstrates that CaO additive can adjust the polymerization of borosilicate glass network, and promote the precipitation of whole‐family CsPbX 3 PeQDs in glass with a record absorption efficiency above 75%. As a result, the as‐prepared green and red CsPbX 3 @glass (X 3 = Br 3 , Br 1 I 2 ) exhibit high EQEs of 75% and 67%, and can pass harsh stability tests after immersing water, irradiating by intensive blue light and experiencing 85 °C/85%RH aging over 1000 h owing to effective protection of PeQDs from external environment with the help of robust glass matrix. As a proof of concept, a white backlit module is fabricated by coupling a single‐layer yellow PeQDs enhanced film (PQDF) with blue light guide panel, and the designed prototype display device with wide color gamut of 115% of the NTSC 1953 exhibits a more realistic and vivid color images. This work will pave the way for the realization of commercial application of ultra‐stable CsPbX 3 @glass in QD‐backlight displays.