CN209880624U

CN209880624U - Solar cell antireflection film structure

Info

Publication number: CN209880624U
Application number: CN201920819048.3U
Authority: CN
Inventors: 苗凤秀; 连维飞; 李怡洁; 魏青竹; 倪志春
Original assignee: Suzhou Talesun Solar Technologies Co Ltd
Current assignee: Suzhou Talesun Solar Technologies Co Ltd
Priority date: 2019-06-02
Filing date: 2019-06-02
Publication date: 2019-12-31
Anticipated expiration: 2029-06-02

Abstract

The utility model provides a solar cell antireflection coating structure relates to solar cell technical field. The antireflection film structure comprises a first film layer and a second film layer which are sequentially formed on a silicon substrate of a solar cell, wherein the first film layer is a silicon nitride layer, the second film layer is a silicon oxycarbide layer, the thickness of the first film layer is within the range of 50nm to 70nm, and the thickness of the second film layer is within the range of 10nm to 30 nm. The utility model discloses a double-deck antireflection dielectric film that comprises silicon nitride layer and silicon oxycarbide layer through optimizing rete thickness, can reduce solar cell to the reflection of wavelength 500nm following incident light and promote the spectral response of long wave band more than 800nm to battery efficiency has been improved.

Description

Solar cell antireflection film structure

Technical Field

The utility model relates to a solar cell technical field, concretely relates to solar cell antireflection coating structure.

Background

PERC (Passivated Emitter and reader Cell) solar cells are the most mainstream products in the photovoltaic market at present, and the back alumina provides excellent passivation effect, so that the cells have high efficiency and high power, and have strong competitiveness in the market. The front side of the solar cell adopts a selective emitter structure, so that the spectral response of the cell in a short wave band can be improved, and meanwhile, the recombination of a non-doped region is reduced through high sheet resistance diffusion, the passivation effect of the cell is improved, and the open voltage is improved.

To further improve the spectral response of the PERC cell, an antireflective film may be used on the front side of the solar cell. Currently, silicon nitride (SiNx) films are mainly used as front antireflection films of industrialized solar cells, the SiNx films can be provided with multilayer structures to reduce reflection of incident light, and the reflectivity of the currently optimal SiNx film structure can be as low as 3-5%.

However, it is difficult to further reduce the reflectance of the surface of the solar cell by optimizing the multilayer structure of the SiNx film.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a solar cell antireflection coating structure to the not enough among the above-mentioned prior art to the solution is difficult to further reduce the problem of the reflectivity on solar cell surface.

In order to achieve the above object, the utility model adopts the following technical scheme:

the utility model provides a solar cell antireflection coating structure, this structure is including forming first rete and the second rete on solar cell's silicon substrate in proper order, and first rete is the silicon nitride layer, and the second rete is the silicon oxycarbide layer, and the thickness of first rete is in the within range of 50nm to 70nm, and the thickness of second rete is in the within range of 10nm to 30 nm.

Optionally, the first and second film layers are prepared by plasma enhanced chemical vapor deposition.

Optionally, the first film layer is formed by using SiH₄And NH₃The mixed gas of (3) is prepared as a reaction gas.

Optionally, the second film layer is formed by using SiH₄、CH₄And N₂The mixed gas of O is prepared as a reaction gas.

Optionally, the refractive index of the first film layer is in the range of 2.1 to 2.3.

Optionally, the refractive index of the second film layer is in the range of 1.7 to 1.9.

Optionally, a third membrane layer is further formed on the second membrane layer, and the third membrane layer is a porous silica layer.

Alternatively, the third membrane layer is prepared by using a sol-gel method.

Optionally, the thickness of the third film layer is in the range of 5nm to 20 nm.

Optionally, the refractive index of the third film layer is in the range of 1.1 to 1.38.

The beneficial effects of the utility model include:

the utility model provides a solar cell antireflection coating structure is including forming first rete and the second rete on solar cell's silicon substrate in proper order, and first rete is the silicon nitride layer, and the second rete is the silicon oxycarbide layer, and the thickness of first rete is in the within range of 50nm to 70nm, and the thickness of second rete is in the within range of 10nm to 30 nm. The utility model discloses a double-deck antireflection dielectric film that comprises silicon nitride layer and silicon oxycarbide layer through optimizing rete thickness, can reduce solar cell to the reflection of wavelength 500nm following incident light and promote the spectral response of long wave band more than 800nm to battery efficiency has been improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 shows a schematic structural view of an antireflection film of a conventional solar cell;

fig. 2 is a schematic structural diagram of an antireflection film for a solar cell according to an embodiment of the present invention;

fig. 3 is a graph showing the variation of external quantum efficiency with wavelength of a solar cell having a solar cell antireflection film provided by an embodiment of the present invention and a conventional solar cell antireflection film;

fig. 4 shows a schematic structural diagram of an antireflection film for a solar cell according to another embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

Currently, silicon nitride (SiNx) films are mainly used as front antireflection films of industrialized solar cells, and the SiNx films can be provided with a multilayer structure to reduce reflection of incident light. Fig. 1 shows a schematic structural diagram of an antireflection film of a conventional solar cell, and as shown in fig. 1, for example, two layers of SiNx films may be disposed on a silicon substrate to achieve the purpose of antireflection. However, by optimizing the multilayer structure of the SiNx film, the effect of reducing the reflectance is limited.

Fig. 2 shows a schematic structural diagram of an antireflection film for a solar cell provided in an embodiment of the present invention, as shown in fig. 2, the structure includes a first film layer and a second film layer sequentially formed on a silicon substrate of the solar cell, the first film layer is a silicon nitride (SiNx) layer, the second film layer is a silicon oxycarbide (siox (c)) layer, a thickness of the first film layer is in a range of 50nm to 70nm, and a thickness of the second film layer is in a range of 10nm to 30 nm.

Fig. 3 shows a graph of External Quantum Efficiency (EQE) as a function of wavelength for a solar cell having a solar cell antireflection film provided by an embodiment of the present invention and a conventional solar cell antireflection film. In fig. 3, the solid line is the EQE along with the wavelength variation curve of the solar cell having the SiNx/siox (c) dual-layer antireflection film provided by the embodiment of the present invention, and the dotted line is the EQE along with the wavelength variation curve of the solar cell having the conventional two-layer SiNx antireflection film, it can be seen that the EQE of the solar cell having the SiNx/siox (c) dual-layer antireflection film provided by the embodiment of the present invention is obviously higher than the conventional structure in the short wavelength band below 500nm and the long wavelength band above 800nm, that is, the SiNx/siox (c) dual-layer antireflection film can improve the cell efficiency.

By adopting the double-layer antireflection dielectric film consisting of the silicon nitride layer and the silicon oxycarbide layer, the reflection of the solar cell on incident light with the wavelength of below 500nm can be reduced and the spectral response of a long wave band above 800nm can be improved by optimizing the thickness of the film layer, so that the cell efficiency is improved.

In an embodiment of the present invention, the first film layer and the second film layer may be prepared by Plasma Enhanced Chemical Vapor Deposition (PECVD). Specifically, the first film layer (i.e., SiNx layer) is formed by using SiH₄And NH₃The mixed gas of (2) is prepared as a reaction gas for PECVD. The second film layer (i.e. SiOx (C)) is formed by using SiH₄、CH₄And N₂The mixed gas of O is prepared as a reaction gas for PECVD. The refractive index of the first film layer is in the range of 2.1 to 2.3. The refractive index of the second film layer is in the range of 1.7 to 1.9.

The utility model discloses a SiOx (C)/SiNx double-layer antireflection coating prepared by the PECVD method can reduce the reflectivity of the front dielectric film to 1%, and can promote the passivation effect on the surface and promote the opening pressure. The utility model discloses an adopt the PECVD method to prepare SiNx/SiOx (C) double-deck antireflection coating and reduce the reflection of battery at the short wave band, promote battery current, and then promote battery efficiency. In addition, adopt the solar Cell of the double-deck antireflection coating of SiNx/siox (c) that the utility model provides, the battery piece that uses the same conversion efficiency has better encapsulation CTM (Cell module, the percentage of subassembly output and battery piece power sum) than conventional SiNx antireflection coating battery at the subassembly end, promotes subassembly output 1.0W. Adopt the utility model provides a battery that double-deck antireflection coating of SiNx SiOx (C) was prepared, it is darker than conventional SiNx antireflection coating battery in the outward appearance, also show that the antireflection effect of the double-deck antireflection coating of SiNx SiOx (C) is more excellent than conventional SiNx antireflection coating. In addition, the method for preparing the SiOx (C) layer provided by the utility model is easy to integrate into the current production line without adding additional equipment.

Optionally, as shown in fig. 4, a third membrane layer may be further formed on the second membrane layer, where the third membrane layer is a porous silica layer. The porous silica layer generally has a low refractive index, and the reflectance can be further reduced by further providing a low refractive index porous silica layer on the siox (c) layer. The third membrane layer (i.e., the porous silica layer) may be prepared by using a sol-gel method. The thickness of the third film layer is in the range of 5nm to 20 nm. The refractive index of the third film layer is in the range of 1.1 to 1.38.

The above embodiments are only for illustrating the technical conception and the features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and the protection scope of the present invention can not be limited thereby, and all equivalent changes or modifications made according to the spirit of the present invention should be covered in the protection scope of the present invention.

Claims

1. The utility model provides a solar cell antireflection coating structure which characterized in that, includes first rete and the second rete of forming in proper order on solar cell's silicon substrate, first rete is the silicon nitride layer, the second rete is the silicon oxycarbide layer, the thickness of first rete is in the scope of 50nm to 70nm, the thickness of second rete is in the scope of 10nm to 30 nm.

2. The solar cell antireflection film structure of claim 1 wherein the first film layer and the second film layer are prepared by plasma enhanced chemical vapor deposition.

3. The solar cell antireflection film structure of claim 2, wherein the first film layer is formed by using SiH₄And NH₃The mixed gas of (3) is prepared as a reaction gas.

4. The solar cell antireflection film structure of claim 2, wherein the second film layer is formed by using SiH₄、CH₄And N₂The mixed gas of O is prepared as a reaction gas.

5. The solar cell antireflection film structure of claim 3 wherein the refractive index of the first film layer is in the range of 2.1 to 2.3.

6. The solar cell antireflection film structure of claim 4 wherein the refractive index of the second film layer is in the range of 1.7 to 1.9.

7. The solar cell antireflection film structure of any one of claims 1 to 6, wherein a third film layer is further formed on the second film layer, and the third film layer is a porous silicon dioxide layer.

8. The solar cell antireflection film structure of claim 7, wherein the third film layer is prepared by using a sol-gel method.

9. The solar cell antireflection film structure of claim 7 wherein the thickness of the third film layer is in the range of 5nm to 20 nm.

10. The solar cell antireflection film structure of claim 8 wherein the refractive index of the third film layer is in the range of 1.1 to 1.38.