One‐Pot Synthesis of CsPbX3 (X = Cl, Br, I)@Zeolite: A Potential Material for Wide‐Color‐Gamut Backlit Displays and Upconversion Emission

Abstract All‐inorganic perovskite (CsPbX3, X = Cl, Br, I) nanocrystals (NCs) with promising optical properties are recognized as a rising star among photoelectric materials, but their inevitable instabilities limit extensive application. Herein, a new one‐step strategy for encapsulating CsPbX3 NCs with porous zeolite via the hot injection method is explored. By altering the mole ratio of PbX2, the emission wavelength of CsPbX3@zeolite is found to be regularly modulated from blue‐emission (CsPbCl2Br@zeolite, 436 nm) to red‐emission (CsPbBrI2@zeolite, 648 nm), thus enabling full spectrum adjustment. Due to the surface passivation of zeolite to CsPbX3 NCs, CsPbX3@zeolite possess an outstanding quantum yield and display excellent thermal/photo/air stability. Subsequently, white light‐emitting diodes based on green‐CsPbBr3@zeolite and red‐CsPbBrI2@zeolite are constructed and applied to the backlit display, achieving a wide color gamut of 134.2% for NTSC 1953 and 99.8% for Rec. 2020. The CsPbX3@zeolite implanted with a polymethyl methacrylate film is used to realize upconversion emission under an 800 nm laser at room temperature. Furthermore, amplified spontaneous radiation based on CsPbBr3@zeolite films is achieved. These results convincingly indicate broad application prospects for CsPbX3@zeolite prepared via this simple method.