Method for preparing cadmium telluride thin-film solar cell

Abstract

A method for preparing a cadmium telluride thin-film solar cell comprises forming a cadmium telluride layer, and arranging the cadmium telluride layer towards a container which contains a mixture of copper chloride powder and ammonium salt powder, or copper chloride powder only; and then heating the container, so that after the compound in the container gasifies, a back contact layer is formed via condensation on the cadmium telluride layer. According to the invention, the process is simplified, a two-step process of conventional back contact preparation and heat treatment is avoided, and a battery of high conversion efficiency can be obtained through only one-time heat treatment. The battery obtained by the method provided by the invention can have a cell area of 0.49cm<2> and an average conversion efficiency of 11% which is higher than that of batteries of the same batch which use doping graphite paste for back contact preparation.

Description

Technical field [0001] The invention relates to a method for preparing a cadmium telluride (CdTe) thin film solar cell, and belongs to the technical field of thin film solar cells. Background technique [0002] With the growth of population and economy in the world today, the increasing scarcity of energy resources, the deteriorating environment and the increasing demand for electric energy, the development and utilization of solar energy has set off a global upsurge. This is very conducive to the sustainable development of the ecological environment and benefit future generations, so countries around the world are competing to invest in research and development of solar cells. A solar cell is a device that uses the photovoltaic effect to directly convert sunlight energy into electrical energy. There are many types of solar cells, and one of the important ones is thin-film solar cells. [0003] The cadmium telluride thin film solar cell is a compound semiconductor thin film solar...

AI Technical Summary

Problems solved by technology

[0006] At present, there are many materials and structures of the back contact layer, but they all have certain limitations. For example, the back contact with the structure of ZnTe / ZnTe: Cu can effectively improve the performance of the battery and has certain stability, but it is not suitable for large-scale industrial applications. In chemical applications, it is difficult to form a uniform large-area film when it is prepared by the evaporation method. Although a uniform film can be obtained by sputtering deposition, the cost of the target material is high, and there is no advantage for large-area industrialization.

At present, the method of doping graphite paste with the highest conversion efficiency is bulky, and it is not conducive to module production, and the stability of the battery needs to be further explored; for HgTe, a semi-metal, its work function is as high as 5.9eV, which is comparable to that of CdTe. The lattice mismatch is very small, which is very suitable for the back contact material of CdTe, but the deposition temperature of HgTe is as high as 550 ° C, which easily causes the structural change of polycrystalline CdTe, thus hindering its application as a back contact

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