CN218788380U

CN218788380U - Back contact heterojunction solar cell capable of reducing light absorption effect

Info

Publication number: CN218788380U
Application number: CN202223186386.9U
Authority: CN
Inventors: 林锦山; 谢志刚; 廖培灿; 黄晓狄; 黄天福; 张超华
Original assignee: Goldstone Fujian Energy Co Ltd
Current assignee: Goldstone Fujian Energy Co Ltd
Priority date: 2022-11-29
Filing date: 2022-11-29
Publication date: 2023-04-04
Anticipated expiration: 2032-11-29

Abstract

The utility model relates to a back contact heterojunction solar cell capable of reducing light absorption effect, which comprises a silicon wafer, a front passivation film layer arranged on the front surface of the silicon wafer and a front antireflection film layer arranged on the front passivation film layer; the front antireflection film layer is composed of more than two film layers with gradually reduced refractive indexes of the inner layer and the outer layer. An object of the utility model is to provide a can reduce back of body contact heterojunction solar cell of extinction effect has optimized positive membranous layer structure, can reduce the extinction effect of positive rete effectively.

Description

Back contact heterojunction solar cell capable of reducing light absorption effect

Technical Field

The utility model relates to a can reduce back of body contact heterojunction solar cell of extinction effect.

Background

The improvement of the conversion efficiency of the industrial production of the solar cell is a future trend of the development of the solar industry and the gradual replacement of the traditional energy. The front surface of the back contact heterojunction solar cell generally uses an amorphous silicon layer and a silicon nitride layer as a passivation layer and an antireflection layer respectively, however, the amorphous silicon layer and the silicon nitride layer have a certain light absorption effect to influence the improvement of short circuit current, and meanwhile, the amorphous silicon layer has a phenomenon of PID (potential induced degradation) or LID (light induced degradation) in the outdoor long-term working process.

Disclosure of Invention

An object of the utility model is to provide a can reduce back of body contact heterojunction solar cell of extinction effect has optimized positive membranous layer structure, can reduce the extinction effect of positive rete effectively.

The purpose of the utility model is realized through the following technical scheme:

a back contact heterojunction solar cell capable of reducing light absorption effect comprises a silicon wafer, a front passivation film layer arranged on the front surface of the silicon wafer and a front antireflection film layer arranged on the front passivation film layer; the front antireflection film layer is composed of more than two film layers with gradually reduced refractive indexes of the inner layer and the outer layer.

Compare prior art, the utility model has the advantages of:

(1) The refractive index of the front antireflection film layer is gradually reduced from the inside to the outside, so that the light absorption effect of the front side of the battery is effectively reduced, and the short-circuit current of the battery is increased.

(2) The refractive indexes of the front passivation film layer and the front antireflection film layer are gradually reduced from the inside to the outside, and the light absorption effect of the front side of the battery is further reduced.

(3) The front passivation film layer comprises a microcrystalline silicon layer, and the reduction amplitude of PID or LID can be reduced.

Drawings

Fig. 1 is a simplified structural diagram of an embodiment of the present invention of a back contact heterojunction solar cell with reduced absorption.

Detailed Description

A back contact heterojunction solar cell capable of reducing a light absorption effect comprises a silicon wafer, a front passivation film layer arranged on the front surface of the silicon wafer and a front antireflection film layer arranged on the front passivation film layer; the front antireflection film layer is composed of more than two film layers with gradually reduced refractive indexes from inside to outside.

The refractive index of the front antireflection film layer is 1.6-2.3.

The front antireflection film layer is formed by randomly laminating more than two silicon nitride layers or more than one silicon nitride layer and more than one silicon oxide layer.

The front antireflection film layer consists of four silicon nitride layers, and the refractive indexes of the silicon nitride layers on the inner surface and the surface are 2.2-2.3, 2.0-2.1, 1.8-1.9 and 1.6-1.7 in sequence.

The refractive indexes of the front passivation film layer and the front antireflection film layer are gradually reduced from the inside to the outside.

The front passivation film layer is composed of more than two film layers with gradually reduced refractive indexes from inside to outside.

The refractive index of the front passivation film layer is between 2.4 and 3.2.

The front passivation film layer is formed by more than two amorphous silicon layers or microcrystalline silicon layers or by randomly laminating more than one amorphous silicon layer and more than one microcrystalline silicon layer.

The front passivation film layer comprises a low-oxygen-doped microcrystalline silicon layer and a high-oxygen-doped microcrystalline silicon layer from the inside to the outside; the refractive index of the low-oxygen-doped microcrystalline silicon layer is 2.8-3.2, and the refractive index of the high-oxygen-doped microcrystalline silicon layer is 2.4-2.7.

A back passivation layer is arranged on the back of the silicon wafer; the back passivation layer is divided into a first semiconductor region, a second semiconductor region and an isolation region located between the first semiconductor region and the second semiconductor region; an insulating film layer is arranged on the back passivation layer positioned on the isolation region; the insulating film layer and the back passivation layer positioned in the first semiconductor region are provided with a first semiconductor film layer; the first semiconductor film layer and the passivation layer positioned on the back surface of the second semiconductor region film layer are sequentially provided with a second semiconductor film layer and a conductive film layer from inside to outside; the conductive film layer positioned in the isolation region is provided with an isolation groove for insulating and isolating the first semiconductor region and the second semiconductor region.

And correspondingly arranging a first electrode and a second electrode on the conductive film layers of the first semiconductor region and the second semiconductor region.

And a pyramid suede is arranged between the silicon wafer and the back passivation layer.

The insulating film layer comprises a first insulating layer arranged on the back passivation layer and a laser absorption sacrificial layer arranged on the first insulating layer.

The thickness of the insulating film layer is 80nm-1.5um.

The first semiconductor film layer comprises an N-type amorphous silicon layer, and the second semiconductor film layer comprises a P-type microcrystalline silicon layer.

The silicon wafer is an N-type monocrystalline silicon wafer or a P-type monocrystalline silicon wafer.

And an anti-reflection wear-resistant layer is arranged on the front anti-reflection film layer.

The invention is described in detail below with reference to the drawings and examples of the specification:

fig. 1 is a schematic diagram of an embodiment of a back contact heterojunction solar cell capable of reducing light absorption according to the present invention.

A back contact heterojunction solar cell capable of reducing light absorption effect comprises a silicon substrate, a back contact heterojunction solar cell and a solar cell, wherein the silicon substrate can be an N-type single crystal or single casting silicon substrate, can also be a P-type single crystal or single casting silicon substrate, and is preferably an N-type single crystal silicon substrate; in the present embodiment, the structure and production of the N-type single crystal silicon substrate will be mainly described by way of example.

The novel back contact heterojunction solar cell designed by the utility model takes an N-type single crystal silicon substrate as an example, and the structure of the solar cell comprises an N-type single crystal silicon substrate 0, a front passivation layer 1, a front antireflection layer 2, a back intrinsic amorphous silicon layer 3, a back insulating layer 4, a first semiconductor region and a second semiconductor region which are arranged in an interdigitated manner as shown in fig. 1, wherein the first semiconductor region consists of a back N-type amorphous silicon layer 5, a tunneling layer superposed with a P-type microcrystalline silicon layer 6, a transparent conductive layer 7 and an electrode 8; the second semiconductor region is composed of a back P-type microcrystalline silicon layer 6, a transparent conductive layer 7 and an electrode 8.

The passivation layer 1 on the front side consists of intrinsic microcrystalline silicon layers with different oxygen doping: the oxygen-doped microcrystalline silicon layer 11 is mainly characterized by low oxygen content, high refractive index and high passivation effect, and the refractive index is controlled to be 2.8-3.2; the highly oxygen-doped microcrystalline silicon layer 12 is mainly characterized by being doped with higher oxygen content than the microcrystalline silicon layer 11, and having a low refractive index, specifically, the refractive index is controlled to be between 2.4 and 2.7.

The antireflection layer 2 is composed of four layers of silicon nitride with different refractive indexes, wherein the refractive index of the silicon nitride layer 21 is 2.2-2.3, the refractive index of the silicon nitride layer 22 is 2.0-2.1, the refractive index of the silicon nitride layer 23 is 1.8-1.9, and the refractive index of the silicon nitride layer 24 is 1.6-1.7.

The passivation layer on the front surface is formed by introducing silane, carbon dioxide and hydrogen in different proportions into PECVD equipment for deposition.

The antireflection layers with different refractive indexes on the front surface are formed by introducing silane, ammonia gas and nitrogen gas in different proportions into PECVD equipment for deposition.

The first semiconductor area with the back arranged in an interdigital shape is formed by overlapping an N-type amorphous silicon layer and a P-type microcrystalline silicon layer, so that the mask and the contraposition corrosion for many times are reduced, and the manufacturing process is simplified.

The transparent conductive layer 7 is an oxide mainly composed of ITO, and covers the first semiconductor region and the second semiconductor region arranged in an interdigitated manner, and the two adjacent semiconductor regions are insulated and isolated from each other.

The electrode 8 is disposed on the transparent conductive layer 8. Which is a screen printed silver electrode or an electroplated copper electrode.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.

It will be apparent to those skilled in the art that various changes and modifications may be made to the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A back contact heterojunction solar cell capable of reducing the effects of light absorption, comprising: the silicon wafer comprises a silicon wafer, a front passivation film layer arranged on the front surface of the silicon wafer and a front antireflection film layer arranged on the front passivation film layer; the front antireflection film layer is composed of more than two film layers with gradually reduced refractive indexes of the inner layer and the outer layer.

2. The back contact heterojunction solar cell with reduced absorption effect of claim 1, wherein: the refractive index of the front antireflection film layer is between 1.6 and 2.3.

3. The back contact heterojunction solar cell of claim 2, wherein said back contact heterojunction solar cell is capable of reducing absorption effects, and comprises: the front antireflection film layer is formed by randomly laminating more than two silicon nitride layers or more than one silicon nitride layer and more than one silicon oxide layer.

4. The back contact heterojunction solar cell with reduced absorption effect of claim 3, wherein: the front antireflection film layer consists of four silicon nitride layers, and the refractive indexes of the silicon nitride layers on the inner surface and the surface are 2.2-2.3, 2.0-2.1, 1.8-1.9 and 1.6-1.7 in sequence.

5. The back contact heterojunction solar cell with reduced absorption effect of claim 1, wherein: and an anti-reflection and anti-reflection wear-resistant layer is arranged on the front anti-reflection film layer.

6. The back contact heterojunction solar cell with reduced absorption effect according to any of claims 1 to 5, wherein: the refractive indexes of the front passivation film layer and the front antireflection film layer are gradually reduced from the inside to the outside.

7. The back contact heterojunction solar cell of claim 6, wherein said solar cell is characterized in that: the front passivation film layer is composed of more than two film layers with gradually reduced refractive indexes from inside to outside.

8. The back contact heterojunction solar cell of claim 6, wherein said solar cell is characterized in that: the refractive index of the front passivation film layer is between 2.4 and 3.2.

9. The back contact heterojunction solar cell of claim 6, wherein said solar cell is characterized in that: the front passivation film layer is formed by more than two amorphous silicon layers or microcrystalline silicon layers or by randomly laminating more than one amorphous silicon layer and more than one microcrystalline silicon layer.

10. The back contact heterojunction solar cell with reduced absorption effect of claim 9, wherein: the front passivation film layer comprises a low-oxygen-doped microcrystalline silicon layer and a high-oxygen-doped microcrystalline silicon layer from the inside to the outside; the refractive index of the low-oxygen-doped microcrystalline silicon layer is 2.8-3.2, and the refractive index of the high-oxygen-doped microcrystalline silicon layer is 2.4-2.7.