Luminescence and Stability Enhancement of CsPbBr<sub>3</sub> Perovskite Quantum Dots through Surface Sacrificial Coating
Dong Huang, Jun Bo, Ronghong Zheng, Chengzhao Luo, Xiaojuan Sun, Qinyi Li, Dongyang Shen, Zhishuai Zheng, Mengyu Chen, Yixing Yang, Aiwei Tang, Song Chen, Yu Chen
Abstract
Abstract All‐inorganic perovskite quantum dots (QDs) have emerged as a new category of low‐cost semiconducting luminescent materials for optoelectronic applications. However, their poor stability has become the main challenge that impedes their potential applications. Herein, Ni‐doped CsPbBr 3 QDs with lead phosphate (Pb 3 (PO 4 ) 2 ) shell through surface sacrificial coating (c‐Ni‐CsPbBr 3 ) have been developed based on a modified thermal injection approach. The synergistic effect of Ni doping and Pb 3 (PO 4 ) 2 coating effectively improves the stability and optical performances of CsPbBr 3 QDs, including photoluminescence (PL) intensity, the average lifetime, and PL quantum yield (QY). Thus, the c‐Ni‐CsPbBr 3 QDs demonstrate the full width at half maxima (FWHM) and PLQY being 18.42 nm and 90.77%, respectively. The PL intensity of c‐Ni‐CsPbBr 3 can be maintained at 81% of its original value after being heated at 100 °C for 1 h. No phase transformation can be observed after being stored under ambient conditions (25 °C, 60% relative humidity (RH)) for 21 days. In addition, by combining green c‐Ni‐CsPbBr 3 QDs, red CdSe‐based QDs and the blue GaN chip, a QD enhancement film (QDEF) is fabricated to form a liquid crystal display (LCD) backlit with a wide color gamut covering cover 121% of the National Television System Committee (NTSC) standard.