Highly efficient wide-color-gamut QD-emissive LCDs using red and green perovskite core/shell QDs

Abstract

The development of highly efficient and stable red (R) CsPb(Br_0.35I_0.65)₃/CsPb₂Br₅ and green (G) CsPbBr₃/CsPb₂Br₅ core/shell perovskite quantum dots (PeQDs) can facilitate the realization of highly efficient and wide-color-gamut, PeQD-emissive liquid crystal displays (LCDs). The photoluminescence quantum yields (PLQYs) of red and green (RG) core/shell PeQDs reached ∼77.4% and ∼78.9%, respectively. The enhanced photo-stability, water-resistance, and thermal stability of RG core/shell PeQD films imply more opportunities to fabricate RG color-converting films with it to replace color filters (CFs) in conventional LCDs. The realization of color-by-blue PeQD-emissive LCDs can overcome technical challenges related to conventional CF-assisted LCDs, such as improved device efficiency and an enlarged color gamut. The relative conversion efficiency and color gamut of a color-by-blue PeQD-emissive LCD consisting of RG PeQD films sandwiched in the form of a RG-recycling bottom layer and a blue-filtering top dichroic filter are 1.94 times higher and 1.74 times wider than those of a conventional CF-LCD with a 2-phosphor-converted white-light-emitting diode (2pc-WLED). Therefore, the overall enhanced efficiency of PeQD-emissive LCDs was determined to be 4.28 times higher than that of a conventional 2pc-WLED-based CF-LCD. This color-by-blue core/shell PeQD-emissive LCD provides an excellent opportunity for the creation of new types of highly efficient LCDs.