Method for preparing CdTe quantum dots in aqueous phase and at low temperature

Abstract

The invention belongs to the field of preparation of nano materials and relates to a method for preparing CdTe quantum dots in an aqueous phase and at a low temperature. The method comprises the following steps of: preparing solution from dithioamino formate serving as a stabilizing agent, water serving as a solvent, cadmium salt and a ligand according to a certain ratio; injecting sodium hydrogen telluride or potassium hydrogen telluride aqueous solution; and reacting in water bath at the low temperature for a certain time to obtain the water dispersible CdTe quantum dots. The preparation method has the advantages of low reaction temperature, readily available raw materials, convenience of preparation, easiness in operation, low requirement on reaction equipment, low price, energy conservation, environmental friendliness, preparation on a large scale and suitability for industrialization because the CdTe quantum dots are prepared in the aqueous phase completely. The prepared CdTe quantum dots have uniform grain size and high dispersibility, and can serve as solar battery dye sensitive materials or photocatalytic materials.

Description

Technical field: [0001] The invention belongs to the field of nano material preparation and relates to a method for preparing CdTe quantum dots at low temperature in water phase. It specifically relates to the synthesis of dithiocarbamate and the method for large-scale preparation of CdTe quantum dots under low temperature conditions under the regulation of the ligand. Background technique: [0002] When the size of semiconductor nanocrystals reaches or is smaller than its Bohr excitonic radius, it exhibits size-dependent optoelectronic properties, which are called quantum dots. Studies have shown that due to the wide spectral absorption of II-VI quantum dots such as CdTe, the range is adjustable, and they have high carrier transport rates, they are a class of excellent photoelectric conversion materials, which can be used in light-emitting diodes, solar cells, Photodetectors and other fields. Alivisatos et al. reported in 2005 the use of quantum dots such as CdTe to prepa...

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Problems solved by technology

However, the reaction requires high-temperature devices, inert gas protection, high toxicity of reagents, high price, and low yield. The surface of the obtained quantum dots is a hydrophobic alkyl chain, which requires ligand exchange in many fields of applications, and will also reduce the quality of quantum dots. Fluorescence yield of

In short, although the organic phase method can obtain high-quality quantum dots, it is demanding on the entire preparation process, the price is high, and it is difficult to prepare on a large scale, which limits its application in actual production.

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