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.