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

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2018, Vol.6 (47), p.1323-1333
• Main Authors: Yoon, Hee Chang, Lee, Hyeongjin, Kang, Hyelim, Oh, Ji Hye, Do, Young Rag
• Format: Article
• Language: English
• Subjects: Color; Diodes; Efficiency; Emissivity; Filtration; LCDs; Light emitting diodes; Liquid crystal displays; Optical properties; Perovskites; Photoluminescence; Quantum dots; Shell stability; Size distribution; Thermal resistance; Thermal stability; Water resistance; White light
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/c8tc04537b

The development of highly efficient and stable red (R) CsPb(Br 0.35 I 0.65 ) 3 /CsPb 2 Br 5 and green (G) CsPbBr 3 /CsPb 2 Br 5 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. Highly stable and luminescent CsPbX 3 /CsPb2Br 5 core/shell-structure perovskite quantum dot (PeQD) films can be realized as a color-by-blue PeQD-emissive LCD.