Alloy quantum dots as well as preparation method and application thereof

Abstract

The invention discloses alloy quantum dots and a preparation method and application thereof. The preparation method of the alloy quantum dots comprises the following steps: S1, providing a first solution containing CdSeS quantum dots, the average particle size of the CdSeS quantum dots being less than 2nm; and S2, mixing the first solution, a first zinc precursor, a first cadmium precursor, a first selenium-sulfur mixed precursor and a first solvent for reaction to obtain a solution containing CdZnSeS alloy quantum dots. By adopting the preparation method of the alloy quantum dots provided by the invention, the problems in the prior art that when the CdZnSeS alloy quantum dots are synthesized, the fluorescence quantum yield becomes high and then becomes low and the fluorescence half-peak width becomes narrow and then becomes wide as the reaction time goes on is solved, and the alloy quantum dots with high fluorescence quantum yield and narrow fluorescence half-peak width are prepared. When the prepared alloy quantum dots are used for preparing core-shell quantum dots, core-shell quantum dots with low cadmium content per unit absorbance and high fluorescence quantum yield can be obtained.

Description

technical field [0001] The present application relates to the technical field of quantum dot materials, in particular to alloy quantum dots, their preparation methods and applications. Background technique [0002] At present, solution semiconductor nanocrystals with sizes in the quantum confinement range have received extensive attention in the fields of biological imaging and labeling, display, solar cells, light-emitting diodes, and single-photon sources due to their unique optical properties. In the fields of biolabeling and imaging, light-emitting diodes, lasers, and quantum dot photovoltaic devices, quantum dot research has become one of the hotspots in their respective fields. In fields that affect people's daily life such as display (quantum dot backlight TV), lighting, etc., quantum dots have been initially applied in practice. [0003] Among various types of quantum dots, alloy quantum dots are one of the research hotspots in recent years. Unlike traditional bina...

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Problems solved by technology

In 2008, the research group of Professor Seonghoon Lee of Seoul National University in South Korea developed a one-step method to synthesize CdZnSeS alloy quantum dots. The selenium-sulfur precursor was injected into the cadmium-zinc precursor at high temperature for reaction, and the obtained alloy quantum dots had a fluorescence half-peak width The narrowest reaches 24nm, and the fluorescence quantum yield reaches 80%, but as the reaction time progresses, the fluorescence half-peak width gradually widens (greater than 30nm), and the fluorescence quantum yield decreases

But so far, cadmium-free quantum dots cannot compare with cadmium-containing quantum dots in terms of optical properties and synthesis. Therefore, it is necessary to reduce the cadmium in cadmium-containing quantum dots as much as possible without reducing the optical properties of quantum dots. content

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