CN212725326U

CN212725326U - Solar cell front surface multilayer antireflection film and cell

Info

Publication number: CN212725326U
Application number: CN202021012493.8U
Authority: CN
Inventors: 刘海泉; 杨二存; 赵小平; 刘浩东; 高丽丽; 时宝
Original assignee: Tianjin Aiko Solar Energy Technology Co Ltd
Current assignee: Tianjin Aiko Solar Energy Technology Co Ltd
Priority date: 2020-06-05
Filing date: 2020-06-05
Publication date: 2021-03-16
Anticipated expiration: 2030-06-05

Abstract

The utility model discloses a positive multilayer antireflection coating of solar cell and battery, include by supreme carborundum film, first silicon nitride film, second silicon nitride film, silicon oxynitride film and the silicon oxide film that sets gradually down, and the refracting index of each film reduces by supreme down in proper order. The utility model solves the problem that the optical mismatch and the optical loss are caused by the large difference of the refractive indexes between the existing silicon nitride films, can reduce the integral reflectivity of the front surface of the solar cell, reduce the optical loss, increase the optical absorption and improve the conversion efficiency of the solar cell; the utility model discloses because silicon carbonitride film refracting index is great, has excellent passivation ability simultaneously, improves the passivation effect, has further strengthened solar cell's short wave response, has promoted solar cell's anti PID performance. Compared with silicon carbide, the silicon carbonitride has certain chemical activity, and the defect that the silicon carbide cannot be burnt through by the front silver paste to form ohmic contact between silicon and silver is overcome.

Description

Solar cell front surface multilayer antireflection film and cell

Technical Field

The utility model relates to a positive multilayer antireflection coating of solar cell still relates to the battery that contains this positive multilayer antireflection coating of solar cell.

Background

The solar cell is a device which can effectively absorb solar radiation energy and convert the light energy into electric energy by utilizing the photovoltaic effect, and is an important component of a solar cell array power supply system. At present, the crystalline silicon solar cell occupies the market mainstream leading position, and the basic material of the crystalline silicon solar cell is P-type monocrystalline silicon with the purity of 99.9999%, and comprises parts such as a front textured surface, a front P-n junction, a front and back antireflection/passivation film, a front and back electrode and the like. The preparation of the front antireflection film is an important process in the manufacturing process of the solar cell, and can reduce the light reflection of the front side of the solar cell and enhance the passivation capability of the surface of the cell.

At the present stage, an ALD (atomic layer deposition) or PECVD (plasma enhanced chemical vapor deposition) method is mainly adopted to deposit a silicon nitride material on the front surface of the solar cell to prepare an antireflection film, and silicon nitride films with different refractive indexes can be prepared by changing the nitrogen/silicon ratio, and because the silicon nitride with high refractive index has a better surface passivation effect, the silicon nitride with high refractive index is used as a bottom layer; meanwhile, a layer of silicon nitride with low refractive index is required to be prepared to be used as an outer layer, so that the overall refractive index of the antireflection film is ensured to be low, and a good antireflection effect is achieved.

SUMMERY OF THE UTILITY MODEL

A first object of the utility model is to provide a reduce light loss, improve passivation effect, improve the positive multilayer antireflection coating of solar cell of battery conversion efficiency.

A second object of the present invention is to provide a solar cell including the above solar cell front multilayer antireflection film.

The first purpose of the utility model is realized through the following technical scheme: the solar cell front surface multilayer antireflection film is characterized by comprising a silicon carbonitride film, a first silicon nitride film, a second silicon nitride film, a silicon oxynitride film and a silicon oxide film which are sequentially arranged from bottom to top, wherein the refractive index of each film is sequentially reduced from bottom to top.

The utility model provides a great optical mismatch that leads to of refracting index difference between the current silicon nitride rete to cause the problem of light loss, can reduce the positive whole reflectivity of solar cell, reduce light loss, increase light absorption, improve solar cell's conversion efficiency, moreover, the utility model discloses because the silicon carbonitride film refracting index is great, have excellent passivation ability simultaneously, improve the passivation effect, further strengthened solar cell's short wave response, promoted solar cell's anti PID performance. In addition, silicon carbonitride has certain chemical activity compared with silicon carbide, and avoids the defect that silicon carbide cannot be burnt through by the front silver paste, so that ohmic contact cannot be formed between silicon and silver.

Preferably, the silicon carbonitride film of the present invention has a film thickness of 5 to 10nm and a refractive index of 2.3 to 2.6.

Preferably, the first silicon nitride film of the present invention has a film thickness of 25 to 45nm and a refractive index of 2.2 to 2.3.

Preferably, the second silicon nitride film of the present invention has a film thickness of 10 to 30nm and a refractive index of 2.03 to 2.1.

Preferably, the silicon oxynitride film of the present invention has a film thickness of 5 to 10nm and a refractive index of 1.6 to 1.9.

Preferably, the silicon oxide thin film of the present invention has a film thickness of 5 to 10nm and a refractive index of 1.3 to 1.5.

The second objective of the present invention is achieved by the following technical solutions: a solar cell comprises the solar cell front-side multilayer antireflection film.

Compared with the prior art, the utility model discloses the effect that is showing as follows has:

the utility model provides a great optical mismatch that leads to of refractive index difference between the current silicon nitride rete to cause the problem of light loss, can reduce the positive whole reflectivity of solar cell, reduce light loss, increase light absorption, improve solar cell's conversion efficiency.

Compared with the prior art, the utility model discloses because silicon carbonitride film refracting index is great, has excellent passivation ability simultaneously, improves the passivation effect, has further strengthened solar cell's short wave response, has promoted solar cell's anti PID performance.

The utility model discloses a silicon carbonitride, compare with silicon carbide, silicon carbonitride has certain chemical activity, has avoided silicon carbide can not be burnt by the positive silver thick liquids to can't form ohmic contact's shortcoming between silicon and silver.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of the present invention for depositing a front multilayer antireflection film on a silicon wafer.

Detailed Description

As shown in fig. 1, the utility model relates to a solar cell front multilayer antireflection coating, it includes by lower supreme silicon carbonitride film 1, first silicon nitride film 2, second silicon nitride film 3, silicon oxynitride film 4 and the silicon oxide film 5 that sets gradually on silicon chip 6, and the refracting index of each film reduces by lower supreme in proper order. The silicon carbonitride film has a thickness of 5-10nm and a refractive index of 2.3-2.6. The first silicon nitride film has a film thickness of 25-45nm and a refractive index of 2.2-2.3. The second silicon nitride film has a film thickness of 10-30nm and a refractive index of 2.03-2.1. The silicon oxynitride film has a thickness of 5-10nm and a refractive index of 1.6-1.9. The silicon oxide film has a film thickness of 5 to 10nm and a refractive index of 1.3 to 1.5.

The preparation method of the solar cell front surface multilayer antireflection film specifically comprises the following steps:

s1, depositing a silicon carbonitride film 1 on the front surface of the monocrystalline silicon wafer 6 subjected to texturing treatment by using tubular plasma deposition equipment, wherein the deposition temperature is 410-.

S2, depositing the first silicon nitride film 2 on the silicon carbonitride film 1, wherein the deposition temperature is 410-;

s3, depositing a second silicon nitride film 3 on the first silicon nitride film 2, wherein the deposition temperature is 410-;

s4, depositing the silicon oxynitride film 4 on the second silicon nitride film 3, wherein the deposition temperature is 410-;

s5, depositing a silicon oxide film 5 on the silicon oxynitride film 4, wherein the deposition temperature is 410-.

A solar cell comprises the solar cell front-side multilayer antireflection film.

The utility model discloses the mechanism: the antireflection film structure consists of a layer of silicon carbonitride, two layers of silicon nitride, a layer of silicon oxynitride and a layer of silicon oxide from inside to outside, each film layer is coated by deposition of tubular plasma coating equipment, the silicon nitride layer realizes gradual change of the refractive index by controlling the ammonia/silane airflow ratio, and the silicon carbonitride, the two layers of silicon nitride, the silicon oxynitride and the silicon oxide are matched with five different refractions, so that the gradual reduction of the refractive index of the antireflection film from inside to outside is realized, incident light is refracted for multiple times in the film layers, the phenomenon that the incident light directly enters the silicon nitride with high refractive index to cause large-angle refraction and light loss is avoided, and the absorption of the solar cell on short-wave light is enhanced.

The embodiments of the present invention are not limited to the above, according to the above-mentioned contents of the present invention, according to the common technical knowledge and the conventional means in the field, without departing from the basic technical idea of the present invention, the present invention can also make other modifications, replacements or changes in various forms, all falling within the scope of the present invention.

Claims

1. A solar cell front multilayer antireflection film is characterized in that: the silicon carbide nitride film comprises a silicon carbide nitride film, a first silicon nitride film, a second silicon nitride film, a silicon oxynitride film and a silicon oxide film which are sequentially arranged from bottom to top, and the refractive index of each film is sequentially reduced from bottom to top.

2. The solar cell front side multilayer antireflection film according to claim 1, wherein: the thickness of the silicon carbonitride film is 5-10nm, and the refractive index is 2.3-2.6.

3. The solar cell front side multilayer antireflection film according to claim 2, wherein: the first silicon nitride film has a film thickness of 25-45nm and a refractive index of 2.2-2.3.

4. The solar cell front side multilayer antireflection film according to claim 3, wherein: the second silicon nitride film has a thickness of 10-30nm and a refractive index of 2.03-2.1.

5. The solar cell front side multilayer antireflection film according to claim 4, wherein: the silicon oxynitride film has a thickness of 5-10nm and a refractive index of 1.6-1.9.

6. The solar cell front side multilayer antireflection film according to claim 5, wherein: the thickness of the silicon oxide film is 5-10nm, and the refractive index is 1.3-1.5.

7. A solar cell comprising the solar cell front surface multilayer antireflection film according to any one of claims 1 to 6.