Study On The Preparation And Photoelectric Properties Of Three Element CdZnSe Quantum Dots

Semiconductor quantum dots are nanomaterials with three-dimensional dimensions within tens of nanometers.Because of their unique characteristics,such as quantum size effect,surface effect,and good fluorescence properties,for example,its narrow and symmetrical fluorescence emission peak spectrum,the absorption spectrum of quantum dots is relatively wide,and is widely used in many fields,including the solar cells,biological sciences,optoelectronic devices and displays.In this paper,a band tunable CdZnSe/ZnSe ternary quantum dot and a self-emitting white light CdS quantum dot are prepared by using the method of oil phase synthesis.In this paper,we introduced a one-pot method,using Cadmium Oxide?CdO?,Zinc Acetate?Zn?Ac?₂?as raw materials,oleic acid?OA?as ligand,and 1-octadecene?ODE?as solvent,the core-shell CdZnSe/ZnSe quantum dots were prepared by twice injection of Se.By changing the experimental conditions and improving technology,we can gain quantum dots with a series of wavelength,especially in 620-690 nm,which is the prolongation of the material,this material with deep red emitting have not been reported in the previous literature.In order to expand the application of the quantum dot material prepared by the experiment,the QLED was prepared by using high yield of 635 nm and672 nm for light emitting layer,and the efficiency of the external quantum dot of the device run up to 6.8%.On the basis of the above experiments,green yellow and red quantum dots were prepared by dispersed Se in ODE instead of toxic and expensive TBP,under the same conditions such as temperature and injection rate,three different color quantum dots have been applied to white light diodes with excellent performance.Then,the different light-emitting quantum dots prepared in the laboratory are applied to solar cells,and the performance of quantum dots perovskite battery were also investigated,finally obtained an efficient photovoltaic performance solar cells.In addition,the synthesis of CdS quantum dots was investigated,because of that CdS quantum dot quantum size is so small,and usually accompanied with defect peak.It is proved that that the defects of quantum dots are not worthless,rationally utilize and adjust the position and intensity of defect peak,may achieve unexpected result.Through the reasonable optimization of the process in the experiment,When the temperature is250?,with a Cd:S precursor ratio of 1:1,in a short reaction time,the CdS quantum dots with white light-emitting can be prepared.The perfect combination of the main peak and the defect peak is important.The white light CdS quantum dots were used as the light-emitting layer in the photoluminescence device.The CRI of the device was87.9,and suitable CCT was 4619 K.This is an important innovation for the fabrication of white light devices.