| All-inorganic perovskite CsPbX3(X=C1,Br,I)quantum dots have excellent photoelectric properties,such as high photoluminescence quantum efficiency of direct band gap,very narrow emission bandwidth,high charge carrier mobility,low energy disorder,solution processability,tunable full spectral visible luminescence and low material cost.Based on these advantages,CsPbX3 quantum dots have exciting potential application prospects in the fields of optoelectronic devices such as solar cells,light-emitting diodes(LEDs),photodetectors and lasers,thus have become a research hotspot.In recent years,although the research on perovskite quantum dots has made a series of important progress,it is limited by the inherent nature of the perovskite quantum dot material itself and the depth of the current research.There are still some urgent problems to be solved:CsPbX3 quantum dot preparation method is still in an immature stage,which is not conducive to commercial application;CsPbX3 quantum dots are sensitive to water,heat and light,and have poor stability;CsPbX3 quantum dots contain heavy metal lead,and the toxicity of lead hinders its practical application.Starting from material synthesis and design,this paper focuses on the following four aspects:First,doping metal ions partially replace lead ions,adjust the luminescence properties of CsPbX3 quantum dots,reduce the toxicity of quantum dots;second,innovate and optimize CsPbX3 quantum method of synthesis of dots reduces the preparation cost and makes it more commercial value.The third is to add Lewis base as catalyst and surfactant in the synthesis process of CsPbX3 quantum dots to reduce surface defects and improve its luminescence properties.The fourth is to combine CsPbX3 quantum dots with inorganic salts to prepare CsPbX3 quantum dot composites to improve their stability.The specific content and results are as follows:(1)CsPbX3 quantum dots were synthesized by hot injection method,and Mn2+,Cu2+,Zn2+,Al3+ plasmas were successfully doped into CsPbX3 quantum dots to partially replace Pb2+,Which reduced the toxicity of quantuu dots and adjusted their luminescence properties.The quantum dots synthesized by the heat injection method have a good size distribution and high luminous performance.The use of transition metal ions such as Mn2+ and Cu2+ regulates the quantum dot luminescence,which has a broader application prospect.By using the combination of Al3+ and CsPbCl3 quantum dots,a dense layer of Al2O3 is finally formed on the surface of the quantum dots,which provides a possible direction for solving the long-term stability problem of quantum dots.(2)The CsPbCl3:Mn quantum dots were successfully prepared by ultrasonic synthesis.The blue excitons(411 nm)and orange-yellow Mn(601 nm)exhibited luminescence,and they had uniform microstructure and good luminescence properties.This method is low in cost,easy to implement and suitable for large-scale production,making the application of CsPbCl3:Mn quantum dots possible.(3)Introducing triethylamine into the ultrasonic synthesis of CsPbCl3:Mn quantum dots,reducing the Mn2+ concentration on the surface of perovskite quantum dots,degrading the surface defects,significantly improving the luminescence performance,and increasing the quantum efficiency from 17.49%to 40.15%.(4)The CsPbBr3/NaNO3 quantum dot complex was prepared by recrystallizing CsPbBr3 quantum dots with NaNO3.The synthesized product has similar luminescence properties and phase structure to the CsPbBr3 perovskite quantum dots.By changing the content of oleic acid,CsOA and lead bromide in the synthesis system,the synthesis conditions of CsPbBr3/NaNO3 quantum dot composites were optimized to maintain good luminescence properties and to improve the stability of quantum dots. |
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