CN201655813U - Passive film for crystalline silicon solar battery - Google Patents

Abstract

The utility model relates to a passivation film of a crystalline silicon solar cell, which has a layer of ultra-thin passivation silicon dioxide film grown in hot nitric acid liquid on the upper surface of the silicon chip, and the upper surface of the silicon dioxide film is The surface has a layer of silicon nitride film. The structure of the utility model can make the crystalline silicon solar battery not easy to be corroded and moisture-proof, thereby prolonging the service life of the solar battery and further improving the photoelectric conversion efficiency of the solar battery.

Description

Passivation film for crystalline silicon solar cells

technical field

The utility model relates to the technical field of crystalline silicon solar cells, in particular to a passivation film for crystalline silicon solar cells.

Background technique

At present, the main process of silicon solar cells is composed of high-quality crystalline silicon raw materials, good physical PN junction diffusion, high-quality passivation and current collection. After decades of development of crystalline silicon, it is now believed that the breakthrough to further improve the efficiency of production line cells lies in surface passivation, especially the passivation of the back electrode.

Utility model content

The technical problem to be solved by the utility model is to provide a passivation film for a crystalline silicon solar cell in order to solve the above-mentioned shortcomings and deficiencies.

The technical solution adopted by the utility model to solve the technical problem is: a passivation film for a crystalline silicon solar cell, which has a silicon wafer, and on the upper surface of the silicon wafer, there is a layer of ultra-thin passivation formed by growing in hot nitric acid liquid. An oxidized silicon dioxide film with a layer of silicon nitride film on the upper surface of the silicon dioxide film.

The beneficial effect of the utility model is that the structure of the utility model can make the crystalline silicon solar cell not easy to be corroded and moisture-proof, thereby improving the service life of the solar cell, further improving the photoelectric conversion efficiency of the solar cell, saving time and reducing the cost .

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 utility model.

In the figure: 1. Silicon wafer, 2. Silicon dioxide film, 3. Silicon nitride film.

Detailed ways

Now in conjunction with accompanying drawing, the utility model is described in further detail. These drawings are all simplified schematic diagrams, and only schematically illustrate the basic structure of the utility model, so they only show the configurations related to the utility model.

The passivation film of crystalline silicon solar cell as shown in Figure 1 has a silicon chip 1, and on the upper surface of the silicon chip 1, there is an ultra-thin silicon dioxide film 2 that acts as a passivation and grows in hot nitric acid liquid. , the upper surface of the silicon dioxide film 2 has a layer of silicon nitride film 3 .

After the silicon wafer 1 is dephosphorous silicon glass, the silicon wafer 1 is edged, the silicon wafer 1 is put into the hydrogen fluoride liquid dephosphoric silicon glass, the silicon wafer is soaked in the thermal oxidation liquid to grow the silicon dioxide film 2, and then A layer of silicon nitride film 3 is coated on the silicon film 2 to form a passivation film of the crystalline silicon solar cell.

The utility model implements the low-temperature liquid oxidation process developed at present and integrates with the current liquid E-etched process to realize edge engraving between silicon wafer diffusion and silicon nitride coating, dephosphorous silicon glass and ultra-thin dioxide Silicon ultra-thin film preparation, as a method to improve the performance of solar cells at low cost.

On the basis of the normal crystalline silicon cell technology, between the junction diffusion of the silicon wafer and the preparation of the ARC anti-reflection film, the passivation enhancement film on the upper surface of the liquid silicon dioxide ultra-thin film is realized on the basis of the original edge cutting and phosphorus-removed silicon glass Preparation, the thermal oxidation liquid used in it, in which hot concentrated nitric acid has been proven effective, other reference liquids include hydrogen peroxide, hypochlorous acid, concentrated sulfuric acid, etc.

The preparation method of the present utility model:

Example 1:

Put the silicon wafer into the equipment with an integrated liquid environment, clean and diffuse the silicon wafer, dephosphorize silicon glass and cut edges on the back of the silicon wafer in nitric acid or hydrogen fluoride, then soak in hydrogen fluoride, put the silicon wafer into An ultra-thin silicon dioxide film is grown by immersing in a thermal oxidation liquid, and a layer of silicon nitride is coated on the silicon dioxide film to form a silicon nitride film.

Example 2:

Perform plasma dry etching and liquid wet etching on the silicon wafer, clean and diffuse the silicon wafer, and then perform plasma edge cutting on the silicon wafer, soak the silicon wafer with hydrogen fluoride and remove phosphorus silicon glass, put the silicon wafer into the thermal oxidation liquid and soak An ultra-thin silicon dioxide film is grown, and a layer of silicon nitride is plated on the silicon dioxide film to form a silicon nitride film.

Example 3:

Put the silicon wafer into the equipment with an integrated liquid environment or perform plasma dry etching and liquid wet etching, process, diffuse the silicon wafer, soak the silicon wafer in hydrogen fluoride, put the silicon wafer into the thermal oxidation liquid to grow ultra-thin A silicon dioxide film is coated with a layer of silicon nitride on the silicon dioxide film to form a silicon nitride film.

The final effect of silicon dioxide film and silicon nitride film passivation needs to be reflected through heat treatment processes such as sintering.

Claims (1)

1. crystalline silicon solar cell inactivating film, has silicon chip (1), it is characterized in that: described upper surface at silicon chip (1) has the ultra-thin silica membrane (2) that plays passivation that one deck is grown and formed in hot nitric acid liquid, the upper surface of silica membrane (2) has one deck silicon nitride film (3).

Images