高空气及热稳定性CsPbBr3@SiO2复合量子点的制备

Synthesis of CsPbBr3@SiO2 composite quantum dots with high air and temperature stability

三溴铅酸铯量子点(CsPbBr3 QDs)由于具有高的荧光量子产率与窄的半高峰宽,其荧光波长可以覆盖整个可见光区。然而,目前大多数有机无机卤素钙钛矿量子点的水氧及热稳定性较差,通过改进的St?ber法直接在预先合成的13 nm CsPbBr3 QDs表面包覆了一层无定型SiO2层,成功制备了SiO2包覆的CsPbBr3 QDs(CsPbBr3@SiO2)。SiO2包膜后形成了颗粒较大的聚集体,量子点在颗粒内被保护且均匀分散,其形状类似火龙果且量子产率高达80. 9%。CsPbBr3@SiO2在升温至80℃后还能保持90. 7%的PL强度,在紫外灯下持续照射120 h后,保持了95. 1%的PL强度。CsPbBr3@SiO2复合量子点在水和乙醇气氛下均稳定,有利于制造白光发光二极管器件。

Due to high fluorescence quantum yield and narrow half-peak width,cesium lead tribromide(CsPbBr3)perovskites quantum dots(QDs)has the fluorescence wavelengths covering the entire visible region.However,most of the organic-inorganic halide perovskite quantum dots have poor stabilities to water,oxygen and heat,which is an urgent problem to be solved.Thus,SiO2-coated CsPbBr3 QDs(CsPbBr3@SiO2)is prepared by modifying the surface of presynthesized 13 nm CsPbBr3 QDs with an amorphous SiO2 layer through the modified St?ber method.After being coated by SiO2,a large aggregate of particles is formed,and the quantum dots are protected and uniformly dispersed inside the particles.The structure of CsPbBr3@SiO2 composite quantum dots is similar with a pitahaya and the final quantum yield is as high as 80.9%.CsPbBr3@SiO2 can maintain 90.7%of PL strength after heating to 80℃,and even maintains95.1%of PL strength after 120 hours of continuous exposure to UV light.In addition,CsPbBr3@SiO2 composite quantum dots are stable in water and ethanol atmospheres,which facilitates the fabrication of white light-emitting diode devices.