Silicon wafer surface passivation technique

Abstract

The invention provides a silicon wafer surface passivation technique. By preparing a polystyrene sulfonic acid film on the surface of a silicon wafer, passivation of the surface of the silicon wafer is realized; the thickness of the polystyrene sulfonic acid film prepared on the silicon wafer is in a nanometer scale; after passivation of the surface of the silicon wafer through the polystyrene sulfonic acid film, a high-quality passivation effect can be obtained, and minority carrier lifetime can reach more than 20 ms; and besides, preparation of the polystyrene sulfonic acid film can be realized through a spin-coating method, a spraying coating method or a printing method and the like, and the passivation technique is simple in process, does not need vacuum or high temperature, and is safe and convenient to operate. The passivation technique has a very important application value for silicon material detection and silicon solar energy cell surface passivation.

Description

technical field [0001] The invention relates to the field of photovoltaic solar cells, in particular to a surface passivation technology for silicon wafers. Background technique [0002] The interior of the silicon material is a very neat and orderly arrangement of atoms, and the lattice is periodic. Carriers have good migration and transport capabilities inside it. But on the surface of the silicon wafer, due to the periodic interruption of the crystal lattice, a large number of dangling bonds are generated, and these dangling bonds become the recombination centers of carriers, that is, surface recombination. Surface recombination is fatal to solar cells, and strong surface recombination directly leads to extremely poor performance of silicon solar cells. The effect of surface recombination is also very important in the microelectronics industry, such as thin-film silicon transistors, and the interface defect states at the drain have a very important impact on device perf...

AI Technical Summary

Problems solved by technology

[0005] In addition, if only the minority carrier lifetime of silicon wafers is tested to provide data for the detection and screening of silicon materials, the above-mentioned high-temperature vacuum and other technologies are not applicable due to problems such as high cost and complicated operation.

Commonly used is passivation by soaking in hydrofluoric acid and iodine. The important disadvantage of this technology is that the passivation effect is poor. Minority lifetimes are typically below 1 millisecond

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