CN-114203833-B - Manufacturing method of back contact heterojunction solar cell with low laser damage

CN114203833BCN 114203833 BCN114203833 BCN 114203833BCN-114203833-B

Abstract

The invention provides a method for manufacturing a back contact heterojunction solar cell with low laser damage, which comprises the following steps of A, setting a first conductive type film layer with a surface covered by an insulating film layer on one part of a first main surface of a semiconductor substrate to form a first conductive region with a first conductivity type, wherein a1, the first conductive type film layer, the first insulating layer and a laser absorption sacrificial layer are sequentially formed on the first main surface of the semiconductor substrate, a2, removing the laser absorption sacrificial layer in a region except the first conductive region in a laser etching mode, and a3, removing the first insulating layer and the first conductive type film layer which are not covered by the laser absorption sacrificial layer in a chemical etching mode to form the first conductive region with the surface attached with the insulating film layer. The invention aims to provide a method for manufacturing a back contact heterojunction solar cell with low laser damage, which can reduce the laser damage, reduce the thermal attenuation influence and improve the photoelectric conversion efficiency.

Inventors

XIE ZHIGANG
XIE YIFENG
HUANG WEIHUI
ZHANG CHAOHUA
LIN JINSHAN
LIN CHAOHUI

Assignees

福建金石能源有限公司

Dates

Publication Date: 20260512
Application Date: 20211130

Claims (8)

1. A method for manufacturing a back contact heterojunction solar cell with low laser damage is characterized by comprising the following steps of A, arranging a first conductive type film layer with a surface covered by an insulating film layer on a part of a first main surface of a semiconductor substrate to form a first conductive region of a first conductive type; the specific method of the step A is that, A1, sequentially forming a first conductive film layer, a first insulating layer and a laser absorption sacrificial layer on a first main surface of a semiconductor substrate; a2, removing the laser absorption sacrificial layer in the area except the first conductive area by adopting a laser etching mode; a3, removing the first insulating layer and the first conductive film layer which are not covered by the laser absorption sacrificial layer in a chemical etching mode so as to form a first conductive region with the insulating film layer attached to the surface; step B, forming a third passivation film layer and an optical antireflection layer on the second main surface of the semiconductor substrate processed in the step A in sequence, and forming a second conductive film layer on the first main surface of the semiconductor substrate; Step C, removing part of the second conductive type film layer covered on the inner area of the first conductive area by adopting a laser discontinuous etching mode; step D, removing the insulating film layer which is not covered by the second conductive type film layer in a chemical etching mode; The first conductive type film layer is an N-type conductive film layer, and the first conductive type film layer deposition process comprises the steps of forming an oxygen doped microcrystalline layer; the film forming of the oxygen doped microcrystalline layer comprises three process stages, namely, forming a non-oxygen-containing incubation layer with high H 2 /SiH 4 proportion, forming an oxygen-containing microcrystalline layer, controlling the film forming speed of the oxygen-containing microcrystalline N-muc-SiOx H to be 0.2-2 angstrom/s and the thickness of the film forming surface to be 40-200 angstrom, and forming a non-oxygen-containing contact layer; The specific method of the step C is that partial second conductive type film layer covered in the middle area of the first conductive area is removed by laser discontinuous etching, so that a hole array exposing the insulating film layer is formed by the second conductive type film layer covered in the first conductive area, adjacent holes are not contacted with each other, the hole array is formed by more than one row of holes, and the laser is flat-top laser subjected to space shaping.
2. The method of claim 1, wherein the laser absorbing sacrificial layer is deposited on the first insulating layer as a substrate to form an amorphous silicon film.
3. The method of claim 1, wherein the oxygen doped microcrystalline layer has an optical refractive index of 2.2-3.1.
4. The method for fabricating a back contact heterojunction solar cell according to any one of claims 1 to 3, further comprising the step of, E, after the treatment of the step D, arranging conductive layers on the surfaces of the first conductive area and the second conductive area; step F, setting an anti-deposition layer on the conductive layer in a printing mode to form an electrode pattern to be deposited; Step G, forming an electrode on the surface of the area of the conductive layer, which is not covered by the anti-deposition layer; And step H, grooving the anti-deposition layer and the conductive layer area covered by the anti-deposition layer in a laser etching mode or a combination mode of laser etching and chemical etching, wherein the grooving forms separation insulation between the first conductive area and the second conductive area.
5. The method of manufacturing a back contact heterojunction solar cell according to claim 4, wherein the step E is performed by sequentially forming a transparent conductive film and a metal conductive film on the first main surface of the semiconductor substrate processed in the step D to form a conductive layer.
6. The method of manufacturing a back contact heterojunction solar cell according to claim 4, wherein the specific method of the step F is to print plating-resistant ink on the conductive layer obtained by the treatment of the step E.
7. The method of claim 4, wherein the step G is performed by electroplating the first conductive region electrode and the second conductive region electrode on the first conductive region and the second conductive region processed in the step C.
8. The method of manufacturing a back contact heterojunction solar cell according to claim 4, wherein the step H is performed by grooving the deposition-resistant layer by laser etching after the step G, and then etching the conductive layer in the grooved region by chemical etching to form an insulating trench between the first conductive region and the second conductive region.

Description

Manufacturing method of back contact heterojunction solar cell with low laser damage Technical Field The invention relates to a method for manufacturing a back contact heterojunction solar cell with low laser damage. Background The SunPower in the United states is firstly to internationally push out the production of back contact batteries and components, and based on the unique advantages of the back contact technology in terms of power generation efficiency and appearance, the Panasonic heterojunction department starts from 2014 and sequentially inputs the development of heterojunction low-temperature back contact technology, but so far, the back contact technology has a complex process route, frequent battery surface contact damages the surface passivation, which is unfavorable for reducing the production cost of the batteries and improving the mass production efficiency, and the absolute efficiency of the batteries is estimated to be lower by 0.2 percent when one printing technology is added, and the technology of opening a back electrode is mainly based on ink printing and chemical etching, so that the space for reducing the cost is limited. The key of the back contact technology in mass production popularization is to reduce production steps and efficiency damage caused by mechanical contact, and a large number of applications of laser openings can achieve the purpose. However, since the heterojunction based on amorphous silicon is a low temperature process (lower than 200 degrees), the grown film is more sensitive to the thermal effect of laser, and how to reduce the thermal attenuation effect caused by the laser opening is one of the important development problems of the back contact technology. Disclosure of Invention The invention aims to provide a method for manufacturing a back contact heterojunction solar cell with low laser damage, which can reduce the laser damage, reduce the thermal attenuation influence and improve the photoelectric conversion efficiency. The aim of the invention is realized by the following technical scheme: A method for manufacturing a back contact heterojunction solar cell with low laser damage comprises the following steps of A, arranging a first conductive type film layer with a surface covered by an insulating film layer on a part of a first main surface of a semiconductor substrate to form a first conductive region of a first conductive type; the specific method of the step A is that, A1, sequentially forming a first conductive film layer, a first insulating layer and a laser absorption sacrificial layer on a first main surface of a semiconductor substrate; a2, removing the laser absorption sacrificial layer in the area except the first conductive area by adopting a laser etching mode; and a3, removing the first insulating layer and the first conductive type film layer which are not covered by the laser absorption sacrificial layer in a chemical etching mode so as to form a first conductive area with the insulating film layer attached to the surface. Compared with the prior art, the invention has the advantages that: (1) Through setting up laser absorption sacrificial layer, not only can absorb laser, reduce the damage of laser to first conductive region rete, can regard as the etching mask moreover to get rid of the first conductive type rete beyond the first conductive region, and protect the first insulating layer of first conductive region. (2) The second conductive film layer covering the first conductive area is only subjected to laser opening as low as possible, so that the conductive contact between the first conductive area and the electrode is ensured, the working procedures can be reduced, the laser damage is controlled, and the photoelectric conversion efficiency is improved. (3) The N-type conductive film layer adopts an oxygen-doped or non-oxygen-doped microcrystalline layer, and the carrier mobility and the effective doping of the N-type conductive microcrystalline layer are obviously changed relative to those of the N-type amorphous film layer, so that the transverse collecting capability of electrons of the N-type collecting electrode can be greatly improved, and the aperture opening ratio of the N-type electrode can be greatly reduced. Drawings Fig. 1 is a schematic cross-sectional view of a process for manufacturing a solar cell unit according to the present invention. Fig. 2 is a schematic cross-sectional view of a process for manufacturing a solar cell according to the present invention. Fig. 3 is a schematic cross-sectional view of a process for manufacturing a solar cell unit according to the present invention. Fig. 4 is a schematic cross-sectional view of a process for manufacturing a solar cell unit according to the present invention. Fig. 5 is a schematic cross-sectional view of a process for manufacturing a solar cell unit according to the present invention. Fig. 6 is a schematic cross-sectional view of a process for manufacturing a solar c