| Fully inorganic perovskites cesium lead halide?CsPbX3,X=Cl,Br,I?nanocrystals?NCs?,representing bright and tunable photoluminescence,which expected to replace organic-inorganic composite perovskite and II-VI group quantum dot materials in the field of luminescence.The all-inorganic perovskite CsPbX3 QDs can be easily dispersed in various nonpolar solvents?such as hexane and acetone?for solution-based optoelectronic device,but the instability of CsPbX3 QDs impedes the development of CsPbX3 perovskites in devices for the QDs decomposed with time.In this paper,a series of luminescent and adjustable cubic CsPbX3 quantum dots have been successfully prepared by thermal implantation and ion exchange.Dispersing CsPbX3 quantum dots in polymer films and glass substrates can improved the stability of perovskite quantum dots.The morphology,microstructure,optical properties and optoelectronic properties of quantum dots,thin films and glass have been systematically studied by a series of modern analytical and testing methods.The main contents are as the following:1.We have investigated the fluorescent characteristic and the nonlinear optical response of the all-inorganic CsPbX3 NCs.Colloidal CsPbX3?X=Cl,Br,I,and mixed Cl/Br and Br/I systems?NCs present highly luminescent with bright?QY is above 69%?,stable,spectrally narrow,and broadly tunable photoluminescence?425-710 nm with a narrowing of FWHM to 13 nm-30 nm?.CsPbX3 nanocrystals exhibit the regular shift of the peak in XRD and lattice distance differences in TEM,which exhibited the same crystal structure of CsPbCl3,CsPbBr3,CsPbI3 and the mixed compounds.In addition,the nonlinear optical properties of the colloidal CsPbX3 NCs were determined using Z-scan and the results indicated that the NCs had excellent third-order optical nonlinearities.The??3?of the CsPbCl3,CsPbBr3,CsPbI3 were measured to be 2.85×10-11,3.78×10-11,and 3.55×10-11 esu,and figure of merit reaching 4.95,1.85,5.59,respectively.2.Ce-PiG&CsPbX3-ER composite has been successfully fabricated via tape-casting technique.The as-prepared CsPbX3-ER possess excellent PL properties of narrow line-width and bright luminescent emission as CsPbX3 NCs.Remarkably,the air stability of CsPbX3 perovskite is evidently improved by the coating of perovskite.More importantly,we prepare a red film stacking on the Ce-PiG substrate by tape-casting to improve the poor CRI of Ce-PiG based WLED.Impressively,Ce-PiG&CsPbI2Br-ER composite WLED exhibits an excellent chromaticity by simple adjusting the relative red phosphor content?4 wt%?,and easily obtains an optimized white light with a CRI of 90.5,a CCT of 4067 K,a LE of 42.12 lm/W.These results indicate that this composite consisting of YAG:Ce3+PiG and CsPbI2Br-ER red composite can be a promising candidate for applications in warm lighting source.3.Tunable emission CsPbX3 QDs glass has been prepared by melt-quenching method,and the CsPbX3 glass showed better thermal and chemical stability than perovskite QDs solution.The results show that the CsPbX3 quantum dot glass with good crystallization and excellent luminescence can be obtained by annealing at 450?at 1200?.The results emphasized that CsPbX3 QDs glass will be promising for long-lifetime solid-state lighting with tunable emission. |
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