Preparation method of cadmium-free buffer layer in flexible CIGS thin film solar cell

Abstract

The invention discloses a preparation method of a cadmium-free buffer layer in a flexible CIGS thin film solar cell. The method is a chemical water-bath deposition method, and the prepared cadmium-free buffer layer is a zinc sulfide film. The method has the advantages of simple technology, large preparation area, low cost, simple equipment, no requirement of a vacuum system, low deposition temperature, and realization of growing polycrystalline or amorphous semiconductor films having a good stability and a high quality, . More importantly, there is no environmental pollution in the preparation process of zinc sulfide. The preparation method of the zinc sulfide film through chemical water-bath deposition comprises the following steps: 1, sequentially depositing a barrier layer, a back electrode layer and a CIGS absorption layer on a flexible substrate to form a sample; 2, preparing a reaction solution containing a zinc source, a sulfur source, a complexing agent and a buffer agent; 3, placing the sample in the reaction solution, and stirring and heating to prepare a film; and 4, drying a sample obtained in step 3 for later use.

Description

technical field [0001] The invention relates to a preparation method of a cadmium-free buffer layer in a flexible CIGS thin film solar cell. Background technique [0002] In flexible CIGS thin film solar cells, the buffer layer is located at a key position between the absorber layer and the window layer, which plays a very critical role in the cell efficiency. At present, the CIGS thin-film solar cell with the highest efficiency obtained in the laboratory uses cadmium sulfide as the buffer layer. However, since cadmium is a heavy metal, the environmental pollution of cadmium ions limits its further development and application. At the same time, the band gap of the cadmium sulfide film is only 2.4eV, which has a certain influence on the short-wave response of the battery absorbing layer. Therefore, the development of cadmium-free flexible CIGS solar cells has become a global hotspot. Zinc sulfide is currently the most promising buffer layer material to replace cadmium sulf...

AI Technical Summary

Problems solved by technology

In this way, many mature thin film preparation processes cannot be used for the preparation of buffer layers for CIGS solar cells.

Such as magnetron sputtering, physical vapor deposition, etc., due to the existence of high-energy ion flow or high temperature in the process, these processes will have a serious negative impact on the CIGS absorbing layer film

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