Study On The Preparation Of High Stability All Inorganic Perovskite Quantum Dots And Its Performances

All inorganic perovskite CsPbX3 quantum dots(QDs)have potential applications in display and lighting fields due to its excellent performances.However,it is hard to be commercialized due to its poor stability.This study focuses on the construction of highly stable all-inorganic perovskite CsPbX3 perovskite QDs.The main works include:(1)Sodium titanosilicate(CST)matrix was synthesized by hydrothermal method,and CST:CS+ was prepared by ion exchange.The blue light QDs of CsPbBr3 were grown in situ by using reverse sequence heat injection process in the inherent nano channel of CST.The CsPbBr3 QDs has a size of around 3 nm,the excitation wavelength is 300 nm-400 nm,the peak emission wavelength is 463 nm with a half peak width of 19.7 nm,and the CIE coordinates are(0.135,0.062).The fluorescence quantum efficiency is 88.34%,and the average fluorescence lifetime achieves at 112 ns.After 15 days exposure to air,the luminescence intensity still remains above 80%,and the QDs show good thermal stability in a 20℃-100℃ testing cycle.(2)HAP&CsPbBr3 green QDs were prepared by room temperature recrystallization method based on the ion exchange adsorption of Pb2+on HAP.The size of the QDs was 6.32 nm,the excitation wavelength was 340 nm-370 nm,the optimal excitation peak was 361 nm,the emission peak was 525 nm with a half peak width of 18.9 nm.The CIE coordinates were(0.1257,0.7815),the fluorescence quantum efficiency was 79%,and the average fluorescence lifetime achieves 110.22 ns.As well as,the residual luminous intensity was 62%of the initial after 15 days exposure to air,and 70%was maintained in the thermal stability test at 20℃-100℃.(3)Based on the natural hydrolysis of 3-aminopropyltriethoxysilane(APTES)in air to form SiO2.SiO2@CsPb(Br/I)3 red QDs were prepared by thermal injection method.The optimal excitation wavelength was 503 nm,the emission wavelength was 603 nm and the CIE coordinates were(0.585,0.412).(4)The CST:CsPbBr3 blue light quantum dots,HAP&CsPbBr3 green light quantum dots,and SiO2@CsPb(Br/I)3 red quantum dots synthesized in this study were encapsulated to fabricated a pure perovskite quantum dots white LED,and it achieves at a color gamut value of 103.36%.