Ultra‐Pure 531 nm Green‐Emitting CsPbBr 3 @Glass With a High Quantum Efficiency for Rec. 2020 Backlit Display

ABSTRACT CsPbBr 3 perovskite quantum dots (PeQDs) glass (CsPbBr 3 @glass) is regarded as an ideal color‐converter for high‐definition liquid crystal displays (LCDs). However, it is hard to tune green emission into Rec. 2020 required a 530∼540 nm spectral range with high photoluminescence quantum yield (PLQY) so far. This work demonstrates that a synergistic regulation strategy by combining F − doping with a melting water‐quenching can effectively regulate glass network polymerization to simultaneously optimize emissive wavelength and PLQY of the crystallized PeQDs in glass. As a result, the obtained CsPbBr 3 @glass exhibits 531 nm green luminescence with a high PLQY of 95%, whose brightness is twice of commercial β‐Sialon phosphor within the visually sensitive 525–535 nm spectral range. Importantly, this strategy does not compromise the protective role of a robust glass network, enabling CsPbBr 3 PeQDs to withstand 85°C/85% RH industrial aging tests and 1200 W/m 2 blue light irradiation over 1000 h. As a proof‐of‐concept, a monolithic yellow PeQDs enhanced film (PQDF) by dispersing green/red CsPbX 3 @glass (X 3 = Br 3 , Br 1 I 2 ) in polydimethylsiloxane (PDMS) is prepared to construct a 9‐inch LCD prototype device, showing superior color presentation and rendering compared to a conventional phosphors‐based LCD. This achievement establishes a foundation for advancing practical applications of CsPbX 3 @glass in QDs‐converted backlit LCDs.