Method for preparing copper antimony sulfide solar cell light-absorbing layer film

Abstract

The present invention discloses a method for preparing a copper antimony sulfide solar cell light-absorbing layer film. Light-absorbing layer copper antimony sulfide is prepared by stree-step multi-source co-evaporation deposition process, the anti-evaporation of antimony sulfide is effectively compensated, a film composition is precisely controlled, the crystallinity of the film is improved, film bottom is in antimony, the film adhesion is enhanced, a surface layer is rich in antimony, the generation of a surface layer rich copper phase is inhibited, and the leakage current of a solar cell is reduced. Compared with a chemical method, the method of the invention has the advantages that the crystallinity and component controllability of the copper antimony sulfide is improved, the miscellaneous phase formation is suppressed, the carrier recombination of a space charge region is reduced, and the improvement of cell efficiency is facilitated.

Description

1. Technical field [0001] The invention relates to a method for preparing a solar cell light-absorbing layer film, in particular to a method for preparing a copper-antimony-sulfur solar cell light-absorbing layer film. 2. Background technology [0002] Copper antimony sulfur (CuSbS 2 ) is similar to the traditional high-efficiency thin-film solar cell absorber copper indium gallium selenide, which also has the advantages of high light absorption coefficient and band gap matching with the solar spectrum. Compared with copper indium gallium selenide, its element antimony is cheaper than indium and gallium. In addition, its crystallization temperature is much lower than that of copper indium gallium selenide, so the cost of raw materials and production is greatly reduced, and it is considered to be the most promising new generation of solar cells. [0003] The copper antimony sulfur light absorbing layer is the core layer of the battery. At present, most reports in the litera...

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Problems solved by technology

At present, most reports in the literature use chemical methods to prepare copper-antimony-sulfur light-absorbing layers. Although this method reduces the manufacturing cost compared with vacuum methods, there are several main problems: First, chemical methods need to use organic solvents or water solvents, and the solutes are mostly various. It is a salt compound of constituent elements, so it is easy to introduce impurities, and semiconductor materials are extremely sensitive to the content of impurities, and a very small amount of impurities may greatly reduce its electrical properties

In copper antimony sulfur, the evaporation temperature of copper and antimony is very different, especially the evaporation temperature of antimony is only 500-600 °C, and the saturated vapor pressure of its element and sulfide is relatively high, which is very easy to reverse evaporation, resulting in the loss of antimony. If the one-step method is adopted, once the substrate temperature is high, a large amount of antimony elements will be lost, and the film is rich in copper, and the copper-rich copper antimony sulfur is Cu with low resistance. 12 Sb 4 S 13 Phase, this phase will cause battery leakage and cannot be used as a light absorbing layer

If the substrate temperature is lower, although the anti-evaporation of antimony sulfide can be reduced, the crystallinity of copper antimony sulfur generated at lower temperature is poor and there are more defects

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