Preparation And Research On Photoelectric Properties Of Environmentally Stable Composite Materials Based On CsPbBr₃ Perovskite Nanocrystals

All-inorganic lead cesium halide perovskite(CsPbX3,X=Cl,Br,I)nanocrystals(NCs)have received widespread attention due to their excellent photoelectric properties,such as tunable emission in the entire visible spectrum,narrow emission spectrum,high photoluminescence quantum yield(PLQY)and wide color gamut.These outstanding characteristics make perovskite NCs have considerable potential in various applications,such as LEDs,lasers,solar cells,photocatalysis,plant lighting and photodetectors.However,the stability of CsPbX3 perovskite NCs is poor,and it is easy to decompose and lose its proper performance under humid environment,thermal environment and light irradiation,which limits its further application in practice.Therefore,it is necessary to prepare a composite material that can not only maintain the excellent photoelectric properties of perovskite NCs but also ensure its stability.For this reason,we prepared a series of Cd2+ion-doped perovskite nanocrystalline glasses by high-temperature sintering with a subsequent heat-treatment method,and prepared blue luminescent CsPbBr3 nanocrystals composited with natural mineral halloysite nanotubes(HNTs)by hot-injection method.We analyzed its microscopic morphology,stability,and photoelectric properties and the results are shown as follows:1.We successfully synthesized Cd2+ion-doped CsPbBr3 nanocrystals in borosilicate glass by traditional high-temperature sintering with a subsequent heat-treatment method,which improved its PLQY.At the same time,because of the encapsulation of the glass network,the chemical stability and light,heat and water stability are improved,resulting in a reduction in the release of heavy metal lead.On this basis,CsPb0.7Cd0.3Br3 NCs glass,commercial red phosphor(CaAlSiN3:Eu2+)and blue light chips were coupled to produce white LED devices with excellent optical parameters.2.CsPbBr3@HNTs composite materials were prepared by hot-injection method.By controlling the reaction temperature,blue luminescence CsPbBr3 NCs with adjustable photoluminescence(489-519 nm)were prepared and successfully recombined with HNTs.Due to the large specific surface area and porous structure of HNTs,the CsPbBr3@HNTs composite material has a high loading capacity,which enhances the chemical stability of perovskite NCs and reduces the escape of lead ions.Under the excitation of 395 nm InGaN blue-violet chip,CsPbBr3@HNTs powder and commercial red CaAlSiN3:Eu2+phosphor were compounded to obtain a white light-emitting LED device.This work provides a new way for the synthesis and application of blue-emitting CsPbBr3 perovskite materials in white LEDs and display devices.