Synthesis And Surface Photovoltage Characteristics Research Of CdSe Nanocrystals

The preparation of nanocrystalline CdSe by aqueous phase synthesis method areadopted respectively, ligand thioglycolic acid (TGA), mercaptopropionic acid (MPA) andL-cysteine (L-Cys), prepared by the outermost package by the ligand, the middle layer isthe core part of cadmium sulfide, core-shell structure nano cadmium selenide crystal.Firstly the surface photo voltage device independent packed with vacuum system,detection of the atmospheric environment, TGA, MPA and L-Cys were respectively usedas the ligand surface photovoltaic properties of CdSe quantum dots. The results foundusing different ligands for preparing surface photovoltaic properties of cadmium selenidequantum dots have obvious difference. Secondly, with the surface photovoltaic propertiescomparison of atmospheric environment samples, vacuum environment (10-6Pa) obviouslychanged the surface photovoltaic properties of cadmium selenide quantum dots cleansurface. Finally, experiments testing a variety of small atmosphere (e.g. nitrogen, oxygen,water vapor and ethanol steam) surface photovoltaic properties of cadmium selenidequantum dots in the experimental environment, experimental results show that the oxygenmolecule CdSe nanocrystalline surface adsorption photovoltaic response after differentwavelength peak has been improved to a certain extent; all of the response peak innitrogen in the environment are reduced, this shows that nitrogen environment has certaininhibition effect on all of the response peak; similar in nitrogen environment, water vaporenvironment response peaks all decreased significantly, indicating that surfacephotovoltaic water vapor on the response of the sample has the obvious inhibitory action;in ethanol steam environment, surface photovoltage the response of the sample increasedsignificantly, this shows that the diffusion adsorption of ethanol molecules on the surfaceof the photogenerated carriers had obvious promoting effect.In addition, different ligand for the samples prepared in a variety of small atmosphereenvironment field induced surface photovoltage spectrum detection, results show that theexistence of more than two different mechanisms of charge transfer in CdSenanocrystalline samples.