Method for preparing light thermal diffusion junction for silicon solar cell

Abstract

The invention provides a method for preparing a light thermal diffusion junction for a silicon solar cell. In the method, a layer of N-type slurry or P-type slurry is uniformly coated on the surface of a silicon chip and is irradiated through a heating light source, so that the temperature of the N-type slurry or P-type slurry rapidly rises under the irradiation of the heating light source, and doping agents in the N-type slurry or P-type slurry diffuse to the surface layer of the silicon chip at a high temperature so as to form a P-N junction or a high-low junction. The process of preparing the solar cell diffusion junction is realized in an illumination heating mode, and compared with the conventional high-temperature thermal diffusion process, the method has the advantages that: the process time is short, the diffusion layer parameters are controlled, and the thermal damage of the silicon chip due to the long-term high temperature can be avoided; moreover, the performance of the solar cell is greatly improved, and the production cost is reduced.

Description

technical field [0001] The invention relates to a solar cell, in particular to a junction method for light-induced thermal diffusion of a silicon solar cell sheet. Background technique [0002] The preparation of the P-N junction of crystalline silicon solar cells is the core process of solar cells. At present, the process route for the industrialization of crystalline silicon solar cells to prepare P-N junctions is to use the method of high-temperature thermal diffusion in a diffusion furnace. In an atmosphere containing dopants, the silicon wafer is heated to above 700 ° C, and after a high-temperature process of more than 15 to 30 minutes , so that the dopant diffuses to the surface of the silicon wafer to form a P-N junction with the required concentration and depth. [0003] The preparation method of the P-N junction of industrial crystalline silicon solar cells is a long-term high-temperature process. On the one hand, the process consumes a lot of energy and takes a l...

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Problems solved by technology

[0003] The preparation method of the P-N junction of industrial crystalline silicon solar cells is a long-term high-temperature process. On the one hand, the process consumes a lot of energy and takes a long time, which seriously affects production costs and production efficiency; on the other hand, high temperature will cause thermal damage to silicon wafers. , the huge temperature difference between the inside and outside of the silicon wafer when it comes out of the furnace produces thermal stress, which can easily cause hidden cracks in the silicon wafer, resulting in debris in the subsequent process.

In addition, the preparation process of high-efficiency crystalline silicon solar cells often requires two or more high-temperature processes, the process is complicated, the process is difficult to control, and the production cost is high.

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