A kind of solar cell epitaxial wafer and its manufacturing method

Abstract

The invention discloses a solar cell epitaxial wafer and a manufacturing method thereof. The solar cell epitaxial wafer comprises a substrate, a buffer layer, a combined sacrificial layer and a solar cell layer which are arranged sequentially, wherein the combined sacrificial layer comprises a first sacrificial layer, a second sacrificial layer and a third sacrificial layer; the first sacrificial layer is closely adhered to the buffer layer; the third sacrificial layer is closely adhered to the solar cell layer; the second sacrificial layer is arranged between the first sacrificial layer and the third sacrificial layer; and the rate at which the second sacrificial layer is corroded is faster than the rate at which the first and third sacrificial layers are corroded. The solar cell epitaxial wafer and the manufacturing method thereof solve the technical problem that a substrate and a solar cell layer corresponding to a part, which is corroded earlier, of a sacrificial layer are slowly corroded due to direct contact with a corrosive liquid for a long time when an epitaxial stripping technology is adopted for manufacturing a solar cell in the prior art. The solar cell epitaxial wafer can reduce the damage of the corrosive liquid to the substrate and the solar cell layer, and ensures reutilization of the substrate and performance of the solar cell products.

Description

technical field [0001] The invention relates to the technical field of solar cells. Specifically, it relates to a solar cell epitaxial wafer and a manufacturing method thereof. Background technique [0002] GaAs solar cell technology is developing rapidly, and its application fields have gradually expanded from space applications to ground applications. It has broad market prospects in the fields of portable energy and consumer electronics. Using epitaxial lift-off technology (ELO technology) to make GaAs solar cells, on the one hand, the GaAs substrate can be reused after peeling off, which can significantly reduce product costs; on the other hand, flexible GaAs solar cells can be made, and the efficiency is not only improved compared to before stripping , and the product is lighter and flexible, which is more conducive to aerospace and portable applications, etc., and has a wide range of uses. [0003] In the prior art, the process of making GaAs solar cells using epitax...

AI Technical Summary

Problems solved by technology

Although the HF solution generally selected has a large corrosion selection ratio for AlGaAs (sacrificial layer) and GaAs (GaAs battery layer and substrate), in the production environment, it is inevitable that other acids (hydrochloric acid, sulfuric acid) will be introduced into the HF solution. , phosphoric acid, etc.) substances or impurities, plus dissolved oxygen molecules in the solution, can easily lead to the slow corrosion of the GaAs battery layer and substrate corresponding to the earlier corroded sacrificial layer

Because of its slow corrosion rate, this process is not easy to be monitored in real time, but after a few hours for the entire peeling process, several pinholes or similar defects will be formed on the surface of the substrate and the peeled surface of the GaAs battery layer

This will have a certain degree of negative impact on the repeated use of substrates and the performance of solar cell products, and even cause a decline in the overall yield of the production line.

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