Preparing method for CdSe@CdS core-shell structure quantum dots

Abstract

The invention belongs to the technical field of preparation, and particularly relates to a preparing method for CdSe@CdS core-shell structure quantum dots. The preparing method includes the steps that CdSe quantum dots are synthesized in a microemulsion system containing thiourea, a selenium source and excessive Cd2+ ions, then hydro-thermal treatment is conducted on the reaction system, a CdS layer is formed on the surface of CdSe with S2- generated by thiourea decomposition through epitaxial growth, and then the CdSe@CdS core-shell structure quantum dots are formed. A microemulsion and a hydro-thermal treatment method are combined, one-step charging and two-stage reacting are adopted to prepare the CdSe@CdS core-shell structure quantum dots which are small and uniform in size, high in crystallization degree and good in monodispersity, the particle size is easy to control, technological operation is simple, and the requirement for equipment is low.

Description

technical field [0001] The invention belongs to the field of preparation of quantum dots, in particular to a preparation method of CdSeCdS core-shell structure quantum dots. Background technique [0002] The performance of quantum dot materials is not only related to its chemical composition, but also related to its particle size, uniformity of distribution, and crystallinity of particles. At present, the preparation methods of quantum dots mainly include microemulsion method, hydrothermal method, precipitation method, etc., among which the microemulsion method is the most commonly used method. The device is simple, easy to operate, and the product particle size is uniform. By adjusting the composition of the microemulsion, The size of the product can be easily and effectively controlled. However, the nanoparticles prepared by the simple microemulsion method have poor crystallinity and many defects, which become non-radiative recombination centers and affect the optoelectro...

AI Technical Summary

Problems solved by technology

However, the nanoparticles prepared by the simple microemulsion method have poor crystallinity and many defects, which become non-radiative recombination centers and affect the optoelectronic properties of nano-semiconductors.

The hydrothermal method is a common method for preparing nanomaterials. It has the advantages of high particle purity and high crystallinity, but the size of the product particles is not easy to control and the uniformity is poor.

In addition, the current preparation of quantum dot materials with core-shell structure, whether it is the microemulsion method or other methods, generally prepares the core particles first, and then adds the reactants that form the shell layer to carry out the deposition and growth of the shell layer. This method is unavoidable. Agglomeration of core particles, resulting in poor product monodispersity and poor crystallinity

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