Synthesis of ZnSe fluorescent quantum point

Abstract

The invention belongs to a method for synthesizing semiconductor nano materials, in particular to a method for synthesizing ZnSe fluorescence quantum dots. The method comprises the following steps: under the protection of inert gases, Se and a coordination solvent are heated and stirred to obtain a Se precursor; octadecylene, a zinc source body and long chain ethoxylated fatty amine are stirred and mixed to obtain a Zn precursor; after the Zn precursor is heated up to 300 to 350 DEG C, at the same time of stirring, the Se precursor is rapidly injected into the Zn precursor, the reaction system temperature rapidly drops, a nanocrystal begins to grow, and then the sampling immediately begins, so as to obtain a crude product of an original solution of the ZnSe quantum dots; the crude productis dissolved by a low-level organic solvent after separation and purification, so as to obtain a final product-a clear solution of the ZnSe quantum dots. The method has the advantages of simple reaction system, easy material preparation, simple operation, less environmental pollution, high fluorescence quantum yield of the quantum dots, and good crystallinity.

Description

technical field [0001] The invention relates to a method for synthesizing semiconductor nanomaterials. In the reaction system, long-chain alkylamines serve not only as activators for Zn precursors, but also as high-temperature solvents. ZnSe quantum dots are synthesized by using a single organic phosphine coordination solvent in the organic phase. Methods. Background technique [0002] Semiconductor quantum dots, also known as semiconductor nanocrystals, are atoms or atomic clusters composed of a very small number of atoms or molecules, and are usually compounds composed of IIB-VI or III-V atoms and silicon atoms. Because the diameter of semiconductor quantum dots is smaller than its Bohr radius, it exhibits very special physical and chemical properties, especially the size and structure of semiconductor nanocrystals lead to it having quantum size effects and dielectric confinement effects, and derived from this The superior luminescent properties of semiconductor nanocryst...

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Problems solved by technology

[0004] In a word, the deficiencies that exist in the synthesis technique of current ZnSe quantum dots are: 1. The quantum dot fluorescence quantum yield of the aqueous phase synthesis route gained is generally low (15-20%); 2. Chinese patent: the application number is 200510016794. In the synthetic route containing organic phosphine in the organic phase, long-chain alkylamine is used to activate the precursor of zinc, and ODE is added as a high-temperature non-coordinating solvent, and two organic phosphine reagents (TOPO and TOP) are used as the precursor of Zn respectively. The coordination solvent of the body and the Se precursor has high toxicity and cost, and the low reaction temperature (less than 300°C) is not conducive to obtaining quantum dots with good crystallinity; 3. The organic In the synthetic route containing organic phosphine, the reaction temperature can be higher than 300°C only when two kinds of mixed high-temperature non-coordinating solvents (ODE and tetradecane) are used to ensure that the obtained quantum dots have high crystallinity and high Fluorescent quantum yield, but the introduction of long-chain alkanes (such as tetradecane) makes the washing of quantum dots very difficult; 4. In the organic phase phosphine-free synthesis route adopted in Chinese patent 200710193410.2, due to the lower reaction temperature (270-300°C), the crystallinity and luminescent properties of the resulting quantum dots are not ideal

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