MIS crystalline silicon solar cell and manufacturing method therefor

Abstract

The invention discloses an MIS crystalline silicon solar cell and a manufacturing method therefor. The manufacturing method comprises the following steps of: a), texturing the front surface of a silicon wafer; b), performing high-sheet-resistance diffusion on the front surface of the silicon wafer to make a p-n junction; c) removing phosphorosilicate glass from the diffused silicon wafer; d) preparing a tunneling layer on the front surface of the silicon wafer; e) preparing an Al positive electrode on the surface of the tunneling layer; f) preparing an Al back electric field and an Ag back electrode on the back surface of the silicon wafer; g) performing high-temperature sintering on the silicon wafer; and h) depositing an antireflection film in a region outside the Al positive electrode. Compared with the prior art, the method has the following beneficial effects that: the Al positive electrode, the tunneling layer and an N+ layer form an MIS structure, and electrons collected by silicon in the N+ layer can completely penetrate through the insulated tunneling layer to be in contact with the Al positive electrode by an MIS tunneling effect, so that the electrons are exported; the Al positive electrode is not in direct contact with the N+ layer due to the isolation of the tunneling layer, so that the p-n junction is not formed again and the conversion efficiency of the cell is not influenced; and the manufacturing cost can be greatly reduced and the conversion efficiency can be improved.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to an MIS crystalline silicon solar cell and a preparation method thereof. Background technique [0002] Solar cells are divided into thin-film solar cells and crystalline silicon solar cells. Regardless of the type of cell, the electrons on p-n need to be collected through metal electrodes, so metal electrodes play a pivotal role in the structure of solar cells. The electrons on the front of the crystalline silicon solar cell are collected through the Ag main grid line and the Ag sub grid line. Due to the high price of Ag and the limited earth reserves, the popularization of solar cells is greatly restricted. At present, many researchers and battery manufacturers focus on the alternative materials of Ag, and have done a lot of work in reducing the manufacturing cost of solar cells, and have achieved certain results. [0003] Alternative materials for Ag include Al and Cu, whos...

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Problems solved by technology

[0003] Alternative materials for Ag include Al and Cu, whose price is much lower than Ag, but there are many disadvantages in the preparation of solar cells: using Al, since Al is a P-type conductor, Al is in direct contact with the N+ layer of a P-type silicon solar cell, The p-n junction will be formed again, which will greatly reduce the conversion efficiency of solar cells; because Cu will destroy the p-n junction, there must be a metal layer between Cu and silicon for isolation, the process is complicated, and Cu is severely oxidized during sintering

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