Indium phosphide quantum dot with core-shell structure as well as preparation method and application thereof

Abstract

The invention provides an indium phosphide quantum dot with a core-shell structure as well as a preparation method and application thereof. The surface of an indium phosphide quantum dot is coated with a zinc sulfide shell layer doped with heteroatoms to form the indium phosphide quantum dot with the core-shell structure with an indium phosphide quantum dot core and a shell layer comprising compounds such as ZnMnS, ZnMgS or ZnSeS, so that the lattice mismatch degree of the quantum dot at a core-shell interface is appropriate, a forbidden band width is wider; at an excitation state, excitons generated at the core of the quantum dot obtained by the method are completely limited to the core and are difficult to migrate to the surface of the quantum dot, and the non-radiation recombination occurs at the surface defect state, thereby remarkably improving the quantum yield of the quantum dots; and the quantum yield of the quantum dot obtained by the method reaches up to 93 percent, an emission peak position is adjustable in a visible light range, and the application potential as a substitute product of traditional semiconductor quantum dot is high.

Description

technical field [0001] The invention belongs to the field of fluorescent materials, and in particular relates to an indium phosphide quantum dot with a core-shell structure and a preparation method and application thereof. Background technique [0002] Quantum dots are inorganic semiconductor nanocrystals with a diameter of less than 10nm. When the particle size is smaller than or close to the exciton Bohr radius, quantum size effects will appear, that is, as the size of quantum dots gradually decreases, the spectrum of quantum dots will appear blue. The smaller the size of the quantum dot, the more significant the blue shift phenomenon. Therefore, by controlling the size of the quantum dot, the width of its energy gap can be easily adjusted, thereby controlling the color of the emitted light. [0003] According to existing research reports, for quantum dots with an alloy structure composed of group II and group VI elements, the current preparation technology is very mature,...

AI Technical Summary

Problems solved by technology

However, at this stage, the theoretical research on the formation mechanism of semiconductor quantum dots composed of group III and group V elements, such as InP quantum dots, is not perfect, so the quantum yield of the prepared InP quantum dots and other materials is low, and it is difficult to be used more widely

[0005] Since the relative electronic mass of the InP quantum dot material is only 0.067, which is much smaller than the relative electronic mass of 0.13 of the traditional CdSe quantum dot, the electronic wave function of the InP quantum dot is more likely to diffuse to the surface, resulting in the possibility of non-radiative recombination of excited state electrons. greatly increased, thereby making its quantum efficiency lower

In the prior art, ZnS shells are often used to coat the surface of InP quantum dots to reduce the occurrence of non-radiative recombination. However, the forbidden band width of ZnS is 3.7eV, which is wider than that of InP quantum dots (1.35eV). The lattice mismatch with InP quantum dots is relatively large, about 7.7%. The above coating structure is prone to defects at the interface, resulting in the low quantum yield of InP quantum dots coated with ZnS

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