CsPbBr3 nanocrystals encapsulated in silica molecular sieve as a stable green light emitting material for backlight display

Abstract

CsPbBr3 nanocrystals (NCs) with highly efficient narrow-band green emission are promising candidates in display applications. However, the poor stability of CsPbBr3 NCs is always a challenge for future development. Herein, CsPbBr3 NCs encapsulated into MCM-41 molecular sieve (MS) composite were designed and prepared via an optimized ultrasonic and stirring treatments, and the as-obtained green-emitters exhibited tunable green emission at the range of 508–523 nm via different concentrations adjustment in perovskite and heat-treatment conversion. In addition, a narrow full-width at half-maximum (FWHM) of 23 nm can be achieved when the PL emission was 523 nm. More excitingly, the optimal photoluminescence quantum yield (PLQY) was as high as 45%. Subsequently, the CsPbBr3@MS composites exhibit outstanding stabilities, showing no loss even after immersing in water for 10 days or irradiated by the 455 nm white light emitting device (WLED) for 2 days. Finally, based on such excellent properties, the WLED composed of green light-emitting CsPbBr3@MS composite, commercial blue chip and red K2SiF6:Mn4+ (KSF) phosphors realized an ultrawide color gamut, covering 125% National Television System Committee (NTSC). Moreover, the best coordinates of green light are (0.1622,0.7513), the composite film prepared with silica gel achieves white color coordinates of (0.3133, 0.2834) at the same time, of which were all meet the commercial standard coordinates. This work highlights the encapsulation process and feasible solid-state reaction methodology to fabricate CsPbBr3 NCs confined in a microporous molecular sieve with high luminescent stability and performance, significantly expanding its great potential in optoelectronic fields.