Study Of The Spectral Regulation Of Inorganic Perovskites Quantum Dots

Based on the re-deposition system to prepare all-inorganic perovskite quantum dots,the properties of the CsPbBr₃ and its device applications,as well as the factors having influence on the spectra of perovskite quantum dots have been explored in this paper.The author have realized the spectral regulation in a certain wavelength range.It provides a new idea for surface manipulation and device application of perovskite quantum dots.At first,the authors focused on the preparation of perovskite quantum dots which were based on the re-deposition system.Compared with the hot-injection method,the feasibility of the re-deposition system was demonstrated.In this system,the relative parameters have been further optimized by comparing the experimental group.The study found that when the volume ratio of acid amine was 2:1,and the dispersion volume ratio of the precursor was 1:50,the perovskite QDs showed the high yield and good stability.Then,the fluorescence properties of the CsPbBr₃ material prepared by the redeposition system were studied.It was found that the photoluminescence peak appeared at 520 nm,and the absorption peak was at 514 nm.At the same time,by dispersing the CsPbBr₃ in the mixed solent which was composed of DMSO,the CsPbBr₃ has demonstrated the property of aggregation-induced emission.When the concentration of n-hexane reaches 70%,a distinct luminescence peak was observed.Finally,the device application of Cs PbBr₃ was explored.The CsPbBr₃ material was used as the light-emitting layer in the structure of light-emitting devices.Through the incorporation of the auxiliary PEO,the higher quality of the Cs PbBr₃ film was obtained and further the efficiency of the devices have been improved.When the PEO doping mass ratio reached 0.08:1,the best efficiency of the devices was obtained:luminance of13,394 cd/m²,current efficiency of 10.42 cd/A and power efficiency of 6.69 lm/W.On the other hand,the authors concentrated on the effect of the perovskite QDs spectrum which was based on the re-deposition system,in order to achieveSpectral regulation.First of all,the spectral effects of different material compositions on perovskite QDs were investigated.By doping the halogen?Cl,Br,I?,the spectrum of perovskite QDs was observed between 425-660 nm.The spectral peaks showed blue-shifted when doped with Cl^-,and the higher the doping ratio,the farther the blue shift wavelength distance was;when doped with I^-,the spectrum demonstrated red-shifted,and the higher the doping ratio,the more dramatic the phenomenon of red shift was.Then,we have studied the effect of reaction temperature on the QDs spectrum.By changing the temperature of the DMF solvent,it was found that the QDs spectrum showed a red shift with the increase of the reaction temperature.It helped us to realize the spectral regulation of CsPbBr₃ QDs in the range of 515-545 nm.Finally,the effect of different acid-amine combinations on the spectra of QDs was studied.When the organic acid carbon chains were longer,the result in QDs spectrum exhibited a blue shift tendency;when the long-chain organic amines were used,the emission spectra of the QDs showed the red-shifted phenomenon.Combining the experimental results,it can be shown that during the process of preparing the perovskite QDs by re-deposition system,there were many factors acting on the perovskite QDs spectrum,such as composition of the materials,reaction temperature,different combination of acid and amine.By taking advantage of them,the spectral regulation has been achieved.