CN204497240U - A kind of passivated reflection reducing of crystalline silicon high-efficiency black appliances pond penetrates multilayer film - Google Patents

Abstract

The utility model relates to a passivation anti-reflection multilayer film for a crystalline silicon high-efficiency black battery. The bottom layer of the passivation anti-reflection multilayer film is a SiOx layer, the SiOx layer has a refractive index of 1.48-1.8 and a thickness of 2-20nm; The middle layer of the passivation anti-reflection film is a SiNx layer. The SiNx layer can be a single-layer SiN or a multi-layer SiN with different refractive indices. The range of the refractive index is 1.9-2.20 and the thickness is 30-70nm; The top layer of the layer film is a SiOxNy layer, the refractive index of the SiOxNy layer is 1.6-1.95, and the thickness is 20-60nm; the total film thickness of the passivation anti-reflection multilayer film is 80-140um, and the refractive index is 1.9-2.1. The multi-layer passivation anti-reflection film of the high-efficiency black solar cell can not only reduce the surface state of the battery sheet, improve the passivation effect, but also reduce the surface reflectivity of the battery sheet, increase the short-circuit current, and also have good anti-PID attenuation characteristics , and the color of the prepared black battery after lamination is darker, uniform and without color difference.

Description

A passivation anti-reflection multilayer film for crystalline silicon high-efficiency black battery

technical field

The utility model relates to the field of solar cells, in particular to a passivation anti-reflection multilayer film for crystalline silicon high-efficiency black cells.

Background technique

At present, with the environmental problems and energy problems getting more and more people's attention, the research and development of solar cells as a clean energy has entered a new stage.

Only part of the sunlight projected on the solar cell array is transmitted to the inside of the cell and converted into electrical energy, while the other part is reflected by its surface. For this reason, two methods are currently used to reduce the reflectivity to the greatest extent. One is to corrode the surface of the battery into a suede surface, forming multiple reflections on the surface, increasing the number of interactions between light and the surface of the silicon wafer, thereby improving The absorption of light by the battery; the second is to coat the surface of the battery with an optical anti-reflection film, usually with an optical thickness of 1/4 or 1/2 of the wavelength. For a single-layer anti-reflection coating, it only has a good anti-reflection effect on a single wavelength, while a multi-layer anti-reflection coating system can produce effective anti-reflection effects on sunlight in a wide spectral range. At present, most of the anti-reflection coatings commonly used in mass production are single-layer silicon nitride anti-reflection coatings, which have relatively high reflectivity and poor passivation effect. Anti-reflection coatings that can reduce reflectivity and improve passivation effect are hot spots in solar cell research.

On the other hand, the SiNx passivation anti-reflection coating on the surface of traditional solar monocrystalline silicon cells is almost always due to the low refractive index, which makes the PID attenuation more serious; or in order to pursue PID Free, the refraction of the SiNx passivation anti-reflection coating is increased. The conversion efficiency of crystalline silicon cells is reduced by 1-2% compared with conventional processes. , and in the current solar panel preparation process, the market pays more and more attention to the problem of chromatic aberration of laminated cells. A few companies or scientific research institutions have launched products to solve the problem of chromatic aberration: black batteries, but these black batteries are either cumbersome to prepare , complex, or reduce the conversion efficiency of the cell, although it is mass-produced in the production line, it reduces the economic benefits.

Utility model content

The technical problem to be solved by the utility model is: to provide a passivation anti-reflection multilayer film for crystalline silicon high-efficiency black batteries. This multilayer film can reduce reflectivity, improve passivation effect, and improve solar cell efficiency. Anti-PID attenuation characteristics, and the color of the cells after lamination is darker, uniform, and without color difference.

The technical scheme adopted by the utility model is: a passivation anti-reflection multilayer film for a crystalline silicon high-efficiency black battery, including a SiOx layer, a single-layer SiNx or a double-layer SiNx layer and a SiOxNy layer deposited sequentially on the surface of a silicon wafer; The total film thickness of the SiOx layer, single-layer or double-layer SiNx layer and SiOxNy layer is 80-140nm, and the refractive index is 1.9-2.1;

In the SiOx layer, single-layer or double-layer SiNx layer and SiOxNy layer, the SiOx layer is the bottom layer; the thickness of the bottom layer SiOx layer is 2-20nm, and the refractive index is 1.48-1.8;

In the SiOx layer, single-layer or double-layer SiNx layer and SiOxNy layer, the single-layer or multi-layer SiNx layer is an intermediate layer; the total film thickness of the intermediate layer is 30-70 nm, and the refractive index is 1.9-2.2;

Among the SiOx layer, single or double-layer SiNx layer and SiOxNy layer, the SiOxNy layer is the top layer; the film thickness of the top SiOxNy layer is 20-60 nm, and the refractive index is 1.6-1.95.

In the multi-layer film, the first thin film deposited directly on the silicon substrate is defined as the bottom layer, and the one away from the substrate is the opposite upper layer. The bottom layer of the passivation anti-reflection multilayer film of the high-efficiency black battery is an SiO _x layer, the middle layer of the multilayer film is a single or multilayer SiN _x layer; the top layer of the multilayer film is a SiO _x N _y layer.

At present, most of the anti-reflection coatings produced on a large scale are single-layer or double-layer silicon nitride anti-reflection coatings, and their anti-reflection effects and passivation effects are relatively poor. The inventor found after research that introducing the _SiOx layer into the bottom layer, because the _SiOx layer has excellent conductivity compared with the SiNx layer, can lead away a part of the enriched charge to prevent the passivation of the anti-reflection film due to charge accumulation. The SiO _x layer can also increase the open circuit voltage of the battery and reduce the overall refractive index of the passivation anti-reflection layer. The middle SiNx layer can further reduce PID attenuation, and the SiNx layer and Si O _x N _y layer stack can greatly reduce the reflectivity of the light-facing surface of the cell, and the Si O _x N _y layer can effectively reduce the reflectivity of the medium and short wavelength bands and improve The short-circuit current of the battery sheet, and the color of the battery sheet after lamination is darker, and the overall uniformity has no color difference.

The beneficial effects of the utility model are: the passivation anti-reflection multilayer film of the high-efficiency crystalline silicon black battery of the utility model can effectively reduce the surface interface state of the silicon chip due to the introduction of the SiO _x layer at the bottom layer, improve the surface passivation effect, and reduce the anti-reflection film simultaneously. The overall refractive index increases the anti-PID attenuation characteristics; the middle layer adopts single-layer or double-layer SiNx to effectively reduce PID attenuation; the top layer adopts Si O _x N _y layer, which forms a stack with the middle layer. Compared with the traditional anti-reflection film, it can Reduce the reflectivity of the medium and short wave bands, increase the short-circuit current of the battery sheet, and make the overall film color of the battery sheet black after lamination, and the overall film thickness ranges from 80nm to 140nm without color difference, all black. The passivation anti-reflection multilayer film of the high-efficiency crystalline silicon black battery of the utility model is based on the traditional monocrystalline silicon battery technology, only changes the film quality structure of the passivation anti-reflection film, is compatible with the traditional crystalline silicon battery technology, and has no effect on ordinary PECVD equipment Special requirements, easy to implement, suitable for large-scale production, and can also be used in some advanced battery technology, such as: back passivation battery, N-type double-sided battery, MWT battery, etc.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Fig. 1 is the structural representation of the preferred embodiment of the present utility model;

In the figure: 1. SiOx layer, 2. Single or double-layer SiNx layer, 3. SiOxNy layer.

Detailed ways

Now in conjunction with accompanying drawing and preferred embodiment the utility model is described in further detail. These accompanying drawings all are simplified schematic diagrams, only illustrate the basic structure of the utility model in a schematic way, so it only shows the formation relevant to the utility model.

Example 1

A method for preparing a high-efficiency solar passivation anti-reflection multilayer film black battery provided in this embodiment includes the following steps:

1). Pretreatment of the original silicon wafer, the pretreatment includes the processes of texturing, diffusion and etching in the battery process;

2). Use PECVD equipment to coat the passivation anti-reflection multilayer film on the diffusion surface. The bottom layer is SiOx layer 1 with a refractive index of 1.50 and a film thickness of 2nm; the middle layer is a single layer of _SiNx layer with a refractive index of 2.05 , the film thickness is 60nm; the top layer is Si O _x N _y layer 3, the refractive index is 1.75, and the film thickness is 25nm;

3).Use the traditional battery printing process to print the back electrode, aluminum back field, positive grid line and positive electrode, and sinter them;

After testing, it is found that the photoelectric conversion efficiency and PID resistance of the solar cells obtained in this embodiment are improved, and the overall color of the solar cell is darker, uniform and free of color difference after being prepared with a black backplane. The specific data are shown in Table 1 below:

The photoelectric conversion efficiency and PID of the solar cell that the present embodiment of table 1 obtains

As can be seen from Table 1: the process efficiency gain of the laminated anti-reflection film prepared by this method is 0.2%, mainly due to the short-circuit current gain of 70 milliamps; while the PID (potential-induced decay) power attenuation is only 3.5%, and the color of the black battery prepared is Uniform and no color difference.

Example 2

A method for preparing a high-efficiency solar passivation anti-reflection multilayer film black battery provided in this embodiment includes the following steps:

1). Pretreatment of the original silicon wafer, the pretreatment includes the processes of texturing, diffusion and etching in the battery process;

2). Use PECVD equipment to coat the passivation anti-reflection multilayer film on the diffusion surface. The bottom layer is SiOx layer 1, the refractive index is 1.65, and the thickness of the film layer is 20nm; the middle layer is a double-layer SiNx layer, and the bottom layer SiN has a refractive index. 2.15, the film thickness is 10nm, the upper SiN refractive index is 2.0, and the film thickness is 50nm; the top layer is SiOxNy layer 3, the refractive index is 1.8, and the film thickness is 50nm;

3).Use the traditional battery printing process to print the back electrode, aluminum back field, positive grid line and positive electrode, and sinter them;

After testing, it is found that the photoelectric conversion efficiency and PID resistance of the solar cells obtained in this embodiment are improved, and the overall color of the solar cell is darker, uniform and free of color difference after being prepared with a black backplane. The specific data are shown in Table 1 below:

The photoelectric conversion efficiency and PID of the solar cell that the present embodiment of table 1 obtains

As can be seen from Table 1: the process efficiency gain of the laminated anti-reflection film prepared by this method is 0.3%, mainly due to the short-circuit current gain of 120 milliamps; while the PID (potential-induced decay) power attenuation is only 3.5%, and the color of the black battery prepared is Uniform and no color difference.

What is described in the above description is only the specific implementation of the present utility model, and various illustrations do not limit the essential content of the present utility model, and those of ordinary skill in the art can make the specific implementation described before after reading the description modification or deformation without departing from the essence and scope of the utility model.

Claims (1)

1. a passivation anti-reflection multilayer film for crystalline silicon high-efficiency black battery, characterized in that: comprise SiOx layer, single-layer SiNx or double-layer SiNx layer and SiOxNy layer deposited successively on the silicon chip surface; Described SiOx layer 1. The total film thickness of the single or double layer SiNx layer and SiOxNy layer is 80-140nm, and the refractive index is 1.9-2.1; Among the SiOx layer, single-layer or double-layer SiNx layer and SiOxNy layer, the SiOx layer is the bottom layer; the thickness of the bottom layer SiOx layer is 2-20nm, and the refractive index is 1.48-1.8; Among the SiOx layer, single-layer or double-layer SiNx layer and SiOxNy layer, the single-layer or multi-layer SiNx layer is an intermediate layer; the total film thickness of the intermediate layer is 30-70 nm, and the refractive index is 1.9-2.2; Among the SiOx layer, single or double-layer SiNx layer and SiOxNy layer, the SiOxNy layer is the top layer; the film thickness of the top SiOxNy layer is 20-60 nm, and the refractive index is 1.6-1.95.