Diffusion technology for crystalline silicon solar cell

Abstract

The invention discloses a diffusion technology for a crystalline silicon solar cell. The diffusion technology includes the step of furnace tube diffusion. Before furnace tube diffusion is carried out, a silicon wafer is oxidized through illumination rapid heat treatment, and an even oxidation film is generated on the surface of the silicon wafer. By means of the diffusion technology for the crystalline silicon solar cell, as the even oxidation layer is formed after the silicon wafer is etched and before phosphorus atoms or boron atoms are deposited, the uniformity of diffused p-n junctions is improved, the in-wafer uniformity and the inter-wafer uniformity of the sheet resistance of the silicon wafer are improved accordingly, and the efficiency of the cell is effectively improved; in addition, when the diffusion sheet resistance is increased to higher than 90 omega per sheet, the uniformity of the sheet resistance can also be effectively controlled; meanwhile, the etched surface is effectively protected through the even oxidation layer, and the silicon wafer is prevented from being polluted by particles in the air or man-made contact; in addition, residual organic matter generated by additives during etching can be pre-removed in the oxidation process.

Description

technical field

[0001] The invention relates to a diffusion process for crystalline silicon solar cells. Background technique

[0002] In the production process of crystalline silicon solar cells, diffusion is the core process. Forming a uniform high-quality p-n junction on the surface of the silicon wafer is the key to improving the efficiency of the cell, and it is also the goal pursued by the process. At present, the diffusion process in conventional production is to deposit phosphorus atoms (or boron atoms) on the surface of the silicon wafer through the volatilization of the liquid phosphorus source (or boron source) in a tubular diffusion furnace, and then diffuse into the silicon wafer. Into a p-n junction. Diffusion using this method is simple in process and low in cost. However, due to the influence of factors such as the surface texture of the silicon wafer, the diffusion boat, temperature difference, and air flow, it is difficult to achieve a uniform diffusion j...