Low-pressure variable-temperature diffusion method of nanometer textured polycrystalline silicon solar cell

Abstract

The invention discloses a low-pressure variable-temperature diffusion method of a nanometer textured polycrystalline silicon solar cell, and relates to the technical field of solar cells. The low-pressure variable-temperature diffusion method comprises the steps of cleaning of silicon wafers, vacuumizing, temperature rising, power on, cooling and wafer discharging. The pressure of diffusion gas keeps 0.001-0.8 Pa, the diffusion temperature range is from 600 to 950 degrees, the silicon wafers used are p-type silicon wafers and n type silicon wafers. Low-pressure diffusion and variable-temperature diffusion are combined, the problem of uneven diffusion of the nanometer textured silicon wafers is resolved, molecular movement of a diffusion source is accelerated under a low-pressure condition, an impurity source in a diffusion cavity is distributed evenly, the partial concentration difference on the surfaces of the silicon wafers is small, and an even diffusion environment is created. Meanwhile, inside a nanometer textured structure, the diffusion length of a gas source is large, the response time is short, and it is represented that similar diffusion source atmosphere exists within a certain period of time.

Description

Technical field: [0001] The invention relates to the technical field of solar cells, in particular to a low-voltage variable-temperature diffusion method for nano-textured polycrystalline silicon solar cells. Background technique: [0002] Polycrystalline silicon solar cells with nano-texture structure can significantly improve the absorption of sunlight, thereby improving the conversion efficiency of the cell. For example, the front surface of polysilicon manufactured by plasma etching technology is a nano-velvet surface with high-efficiency light-trapping structure. [0003] Due to the inhomogeneity of the physical size distribution of the nano-velvet along the y-axis direction, the distribution of phosphorus in the process of phosphorus diffusion to form a pn junction is very uneven. For example, compared with the silicon wafer of ordinary strong acid etching technology, there is The problem of heavy doping on the top and light doping on the bottom reduces the collection...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a method for low-voltage variable temperature diffusion of nano-textured polycrystalline silicon solar cells, which uses low-pressure diffusion combined with variable temperature diffusion to solve the problem of uneven diffusion of nano-textured silicon wafers