Method for boron diffusion of crystalline silicon solar cell

Abstract

The application discloses a method for boron diffusion of a crystalline silicon solar cell. The method comprises: a crystalline silicon solar cell is heated, boron atom pre deposition is carried out on the surface of the crystalline silicon solar cell; boron atom deposition is carried out on the surface of the crystalline silicon solar cell; secondary thermal oxidation and propelling are carried out on the crystalline silicon solar cell; post deposition and post oxidation are carried out on the crystalline silicon solar cell; and blowing and cooling are carried out on the crystalline silicon solar cell. According to the method provided by the application, the minority carrier lifetime can be prolonged and the cell efficiency can be improved on the premise of low cost.

Description

Technical field [0001] The invention relates to the technical field of solar cell manufacturing, in particular to a method for diffusing boron in a crystalline silicon solar cell. Background technique [0002] At present, P-type cells are generally produced on the market, and the diffusion process of P-type cells generally uses phosphorus oxychloride source. In contrast, the diffusion of boron tribromide source of N-type cells The solar cell has better electrical performance and higher efficiency, but it has not been mass-produced, mainly due to the high cost of N-type silicon wafers. [0003] In the existing process of producing N-type solar cells, the boron diffusion process uses a common one-time heating oxidation process, which is directly advanced after deposition, and the boron atoms cannot be fully diffused into the interior, resulting in the deterioration of boron atoms on the surface of the produced cells. If the concentration is too high, a dead layer is produced, which ...

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Problems solved by technology

[0002] At present, P-type batteries are generally produced in the market, and phosphorus oxychloride source is generally used in the diffusion process of P-type batteries. In contrast, the boron tribromide source diffusion of N-type batteries is made The cell has better electrical performance and higher efficiency, but has not been mass-produced, mainly due to the high cost of N-type silicon wafers

[0003] In the existing process of producing N-type batteries, the boron diffusion process adopts a common one-time heating oxidation process, which is directly advanced after deposition, and the boron atoms cannot be fully diffused into the interior, resulting in the loss of boron atoms on the surface of the produced battery. If the concentration is too high, a layer of dead layer will be generated, which will increase the recombination of hole pairs, reduce the lifetime of minority carriers, and lead to a decrease in the efficiency of the cell.

One existing method is to increase the push time, but this method increases the production cost

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