Facile Two‐Step Synthesis of All‐Inorganic Perovskite CsPbX 3 (X = Cl, Br, and I) Zeolite‐Y Composite Phosphors for Potential Backlight Display Application

Abstract Recently developed CsPbX 3 (X = Cl, Br, and I) perovskite quantum dots (QDs) hold great potential for various applications owing to their superior optical properties, such as tunable emissions, high quantum efficiency, and narrow linewidths. However, poor stability under ambient conditions and spontaneous ion exchange among QDs hinder their application, for example, as phosphors in white‐light‐emitting diodes (WLEDs). Here, a facile two‐step synthesis procedure is reported for luminescent and color‐tunable CsPbX 3 –zeolite‐Y composite phosphors, where perovskite QDs are encapsulated in the porous zeolite matrix. First zeolite‐Y is infused with Cs + ions by ion exchange from an aqueous solution and then forms CsPbX 3 QDs by diffusion and reaction with an organic solution of PbX 2 . The zeolite encapsulation reduces degradation and improves the stability of the QDs under strong illumination. A WLED is fabricated using the resulting microscale composites, with Commission Internationale de I'Eclairage (CIE) color coordinates (0.38, 0.37) and achieving 114% of National Television Standards Committee (NTSC) and 85% of the ITU‐R Recommendation BT.2020 (Rec.2020) coverage.