Synthesis And Properties Of CdSe Quantum Dots

The bandgap width of CdSe inorganic semiconductor nanocrystals can be adjusted by its own size,resulting in different emission wavelength of inorganic semiconductor nanocrystals.These inorganic semiconductor nanocrystals can be widely used in the fields of display,energy materials and biomarkers.The most studied semiconductor materials researched by researchers are CdSe nanocrystals.By adjusting the size of CdSe nanocrystals,we can obtain CdSe nanocrystals which cover almost the entire visible region.The main contents of this thesis are as follows: spherical CdSe,rodshaped CdSe and CdSe/CdS quantum dots with different shell thicknesses were synthesized by thermal injection.And the optical properties,morphology,structure,electrochemical properties of the CdSe nanocrystals were studied.The main contents of this thesis are as follows:1.Firstly,CdSe quantum dots of different sizes were synthesized by high temperature thermal injection method in the organic phase.During the reaction,we obtained CdSe quantum dots of different sizes and different luminescent colors by controlling the reaction time.And the various properties of CdSe quantum dots change with reaction time.With the extension of the reaction time,CdSe QDs become larger.2.Secondly,in the organic phase,CdSe quantum dots with different sizes were synthesized by high-temperature thermal injection method to investigate the effect of different reaction time on the products.The samples were characterized by ultravioletvisible spectrophotometer,fluorescence lifetime meter,fluorescence spectrophotometer,electrochemical workstation,X-ray diffraction and transmission electron microscopy.The UV absorption spectra,fluorescence emission spectra,Fluorescence lifetime,structure,morphology,electrochemical response and other aspects were explored.3.Finally,in the organic phase,spherical CdSe QDs were synthesized by hightemperature thermal injection method.CdSe/CdS QDs with different shell thicknesses were synthesized by coating CdS of different quantity on the surface of spherical CdSe QDs.The samples were characterized by ultraviolet-visible spectrophotometer,fluorescence lifetime meter,fluorescence spectrophotometer,electrochemical workstation,X-ray diffraction and transmission electron microscopy.UV absorption spectra,fluorescence emission spectra,fluorescence life,structure,morphology,electrochemical were explored.