Components And Structural Regulation Of CsPbX₃ Perovskite Quantum Dots And Study On Their Luminescence Properties

All inorganic metal halide perovskite quantum dots have excellent photoelectric properties,such as narrow emission spectrum and high fluorescence quantum yield etc.The photoluminescent wavelength can be adjusted from ultraviolet to visible and near infrared range by changing the component,shape or size of the all inorganic perovskite quantum dots.At present,researches on the all inorganic quantum dots are mainly focused on their synthesis methods and their application of photoelectric devices.However,the research on the precise control of optical properties of perovskite quantum dots remains elusive.Also,there is a lack of theoretical research of optical properties of perovskite quantum dots.In this thesis,the luminescence wavelength of all inorganic perovskite quantum dots was precisely regulated by adjusting the halogen components,core/shell structure and doped ions.The research contents are as follows:?1?The all inorganic perovskite quantum dots were synthesized by a hot-injection method,and the synthesis temperature and time of CsPbX₃?X=Cl,Br,I?quantum dots were optimized.The photoluminescent wavelength of the double/triple-halide CsPbX₃?X=Cl,Br,I?perovskite quantum dots was precisely adjusted in the visible by regulating the halogen components.The band gaps and formation energies of the double/triple-halide CsPbX₃?X=Cl,Br,I?quantum dots were evaluated using the projector augmented plane-wave?PAW?method within the framework of Density Functional Theory?DFT?and by means of molecular dynamics simulations.A group of down-converted CsPbX₃?X=Cl,Br,I?perovskite quantum dot LED devices were constructed to demonstrate the potential use of double/triple-halide CsPbX₃?X=Cl,Br,or I?PQDs with full spectrum luminescence. ?2?The core-shell structure CsPbCl₃@CsMnCl₃ quantum dots were synthesized for the first time by using CsPbCl₃ as the core and CsMnCl₃ as the shell.The fluorescence quantum yield and the stability were greatly enhanced comparing with the CsPbCl₃ quantum dots.The thickness of the shell was optimized by varying the molar ratio of MnCl₂ adding into the system.The white LED device based on the core-shell structure CsPbCl₃@CsMnCl₃ quantum dots was prepared and studied.?3?A series of different concentration of Cu²⁺doped CsPbCl₃ quantum dots(CsPbCl₃:Cu²⁺)were synthesized by using a hot-injection method.The effect of Cu²⁺doping concentration on the fluorescence intensity of quantum dots was studied.The CsCuCl₃ nanocrystal with Pb²⁺fully replaced by Cu²⁺ was synthesized,and the synthesis temperature influence on the morphology and fluorescence intensity of CsCuCl₃ nanocrystal was studied.Also,the luminescence mechanism of Cu²⁺doped CsPbCl₃ quantum dots was studied.