Etching solution for selectively etching gallium arsenide solar cell cap layer and preparation method thereof

Abstract

The invention discloses an etching solution for selectively etching a gallium arsenide solar cell cap layer, which is composed of the following components in parts by mass: 5-150 parts of component A, 10-100 parts of component B, 1-20 parts of component C, 1-20 parts of component D and 100 parts of component E. The component A is solid citric acid; the component B is oxydol; the component C is amine compounds; the component D is amino acid compounds; and the component E is deionized water. Preferably, the purity of the component A is greater than 99.8%, and the mass concentration of the component B is 30%. The invention also discloses a preparation method of the etching solution. The etching solution can well control the etching rate, has higher etching uniformity, and thoroughly removes the residues, thereby obtaining the cell gate line structure with smooth side bench.

Description

technical field [0001] The invention relates to a chemical etching solution used in solar cell production, in particular to an etching solution for selectively etching the cap layer of a gallium arsenide solar cell and a preparation method thereof. Background technique [0002] attached figure 1 The epitaxial structure diagram of a concentrating triple-junction gallium arsenide solar cell is shown, which is a GaInP top cell, a GaAs middle cell, and a Ge bottom cell connected in series, and the GaInP top cell absorbs photon energy greater than 1.85eV Sunlight, GaAs cells absorb sunlight with photon energy greater than 1.42eV, and Ge bottom cells absorb sunlight with photon energy greater than 0.67eV. The absorption band is 380-1850nm, covering almost all sunlight bands. The battery with the highest conversion efficiency among solar cells. [0003] In the manufacturing process of the concentrating triple-junction GaAs solar cell chip, after evaporating the electrode grid lin...

AI Technical Summary

Problems solved by technology

But no matter what kind of system, there are corrosion unclean, such as attached figure 2 Shown is a schematic diagram of the grid lines of the concentrating gallium arsenide triple-junction solar cell chip etched by the existing citric acid-hydrogen peroxide system selective etching solution under a metallographic microscope, and there are still many residues beside the electrode grid lines , these residues will produce light absorption and affect the photoelectric conversion efficiency of solar cells

On the other hand, some existing corrosive liquids are accompanied by lateral and lateral corrosion effects during longitudinal corrosion, which can affect the current expansion in mild cases, resulting in a significant increase in the internal resistance of the battery chip, and in severe cases, it can cause grid lines to fall off; and the corrosion process The window is small and difficult to control

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