Chemical bath deposition equipment and method for preparing ZnS thin film

Abstract

The invention relates to chemical bath deposition equipment. The chemical bath deposition equipment comprises a reaction vessel and a chemical bath pot, wherein the reaction vessel is arranged in the chemical bath pot; the reaction vessel is used for holding a substrate and reaction solution; during a reaction process, the reaction surface of the substrate is continuously, repeatedly, partially and gradually exposed out of the liquid level of the reaction solution, and is scoured by the reaction solution. According to the chemical bath deposition equipment, the reaction surface of the substrate during a chemical bath deposition process continuously, repeatedly, partially and gradually exposes the liquid level of the reaction solution, and is scoured by the reaction solution, thus benefiting to rapid preparation of a thin-film material; the chemical bath deposition equipment can be applied to preparation of thin-film solar cell buffer layers such as In2S3, In(OH)3, ZnS, CdS, Zn(1-x)MgxO, ZnSe and ZnO; the prepared thin film is controllable in thickness, few in defects, and uniform and compact, thus increasing the efficiency of thin-film solar cells and reducing the manufacturing cost of the thin-film solar cells. In addition, the invention further provides a method for preparing a ZnS thin film.

Description

technical field [0001] The invention relates to the technical field of thin-film solar cell preparation, in particular to a chemical bath deposition device and a method for preparing a ZnS thin film. Background technique [0002] Solar cells are playing a leading role in renewable energy, and their huge future demand is driving the development of photovoltaic technology. The current second-generation thin-film solar cells include three main types: amorphous silicon, copper indium gallium selenide (CIGS) and cadmium telluride (CdTe). Among them, CIGS thin-film solar cells, as the most promising thin-film solar cells, have attracted scholars from various countries to conduct a lot of research. [0003] CIGS thin-film solar cells are generally composed of: SLG glass (soda lime glass), Mo back electrode, CIGS absorber layer, buffer layer, aluminum-doped zinc oxide window layer, and metal gate electrode are stacked in sequence. Currently, CIGS thin-film solar cells mainly use C...

AI Technical Summary

Problems solved by technology

At present, CIGS thin-film solar cells mainly use CdS as the buffer layer, which has the following disadvantages: (1) CdS has a bandgap width of 2.4eV, which is not ideal for short-wave response; (2) Cd is toxic and easily produces waste liquid that is harmful to the environment

[0018] Although the traditional magnetic stirring equipment can disturb the solution through the rotation of magnetons, it has a slight effect on the large bubbles on the surface of the substrate, but it has a poor effect on the tiny bubbles

And affected by the length of the rotating magneton of the equipment, if the rotating magneton is too short, the area disturbed by the water wave is too small, and the solution is not stirred uniformly; no film deposition

In addition, limited by the length of the rotating magnet, it is difficult to increase the water bath volume of traditional magnetic stirring equipment, resulting in a small water bath volume. When the sample is first placed, the water temperature fluctuates greatly, the deposition time is long, the system is unstable, and the repeatability is poor.

[0019] Therefore, using magnetic stirring and vertically placing the substrate to process the chemical bath deposition, the film formation is uneven, there are many pinholes, and repeated depositions are required to achieve the target thickness, and the deposition time is long, which will accelerate the homogeneous nucleation , leading to the increase of ZnS micelles on the surface of the film and reducing the film performance

The system is unstable and the repetition rate is low, which is not conducive to industrial production, especially not suitable for the preparation of large-area solar cells

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