The Preparation And Properties Of Perovskite Quantum Dots Confined In Zeolites

CsPbX₃?X=Cl,Br,I?perovskite quantum dots?QDs?hold great potential for various photoelectric applications owing to their superior optical properties,such as tunable emissions,high quantum efficiency,and narrow linewidths.However,the major drawback of poor stability 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 CsPbX₃–zeolite-Y composite phosphors,where perovskite QDs are encapsulated in the porous zeolite matrix.The zeolite encapsulation reduces degradation and improves the stability of the QDs under elevated temperature and irradiation of light.A WLED is fabricated using the CsPbX₃–zeolite-Y composites without ion exchange effects,with CIE color coordinates of?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.In consideration of the inferior stability of CsPb?Br,I?₃ QDs,we synthesized Mn²⁺-doped-CsPbCl₃–zeolite-Y as a new red composite phosphor.The composites have much stable emission in orange-red region under elevated temperature,water and long-time light irradiation than the bare Mn²⁺-doped QDs.The LED using CsPb_0.75Mn_0.25Cl₃–zeolite-Y as color converted material exhibit no apparent degradation of luminous efficiency after working for 10 h.A WLED with a 365 nm UV chip coated by a CsPb(Cl_0.5,Br_0.5)₃–zeolite-Y blue phosphor and a CsPb_0.75Mn_0.25Cl₃–zeolite-Y orange phosphor is also achieved.The device possesses the CIE coordinates of?0.34,0.36?,correlated color temperature?CCT?of 5336 K and color rendering index?CRI?of 81.All above proved that CsPbX₃–zeolite-Y composites achieved better stability in color converted LED devices,and can be a competitive candidate luminescent materials for back-light display.