PN junction diffusion method

Abstract

The invention discloses a PN junction diffusion method, which comprises the following steps that: an oxidation layer is formed on the surface of a silicon chip, and phosphorus atoms are provided and pass through the oxidation layer to diffuse into the silicon chip. According to the PN junction diffusion method provided by the invention, firstly, the oxidation layer is formed on the surface of the silicon chip, then, the phosphorus atoms are provided, and in addition, the phosphorus atoms are diffused into the silicon chip through the oxidation layer. Therefore, through the diffusion method of diffusing the phosphorus atoms into the silicon chip through the oxidation layer, the impurity concentration on the surface of the silicon chip can be reduced, the crystal lattice damage to the surface of the silicon chip caused by high-concentration shallow junction phosphorus accumulation diffusion is reduced, and further, the conversion efficiency of battery cells is improved.

Description

technical field [0001] The invention relates to the technical field of production and processing of solar cells, and more specifically, relates to a diffusion method of a PN junction. Background technique [0002] In recent years, the production technology of solar cells has been continuously improved, the production cost has been continuously reduced, and the conversion efficiency has been continuously improved, making the application of photovoltaic power generation increasingly popular and developing rapidly, and gradually becoming an important source of power supply. Solar cells can convert light energy into electrical energy under sunlight irradiation to realize photovoltaic power generation. [0003] The production process of solar cells is relatively complicated. Simply put, the current production process of solar cells mainly includes: texturing, diffusion, etching, coating, printing and sintering. The PN junction is the heart of solar cells and one of the keys to t...

AI Technical Summary

Problems solved by technology

During diffusion, the concentration of phosphorus atoms inside the silicon wafer is distributed in steps, and the concentration on the surface of the silicon wafer is higher than the maximum solid solubility of phosphorus atoms on the silicon wafer, so some phosphorus atoms will be precipitated and cannot be provided as donor impurities. Electrons, on the contrary, will become recombination centers due to lattice mismatch and dislocation, and the minority carrier lifetime is extremely low

Too high surface impurity concentration will cause "dead layer", there are a large number of interstitial atoms, dislocations and defects in the "dead layer", the minority carrier lifetime is much lower than 1ns, and the photogenerated carriers emitted in the "dead layer" are needlessly compounded, resulting in a decrease in efficiency

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