Preparation method of all aluminum doped N-type solar cell

Abstract

The invention relates to a preparation method of an all aluminum doped N-type solar cell. The preparation method comprises the following steps: providing an N-type semiconductor substrate; forming an N+ layer on the front side of the N-type semiconductor substrate, and forming a silicon nitride thin film on the N+ layer; forming an all aluminum back field on the back side of the N-type semiconductor substrate; preparing a positive electrode on the silicon nitride thin film; sintering the N-type semiconductor substrate at high temperature to enable the positive electrode to be in contact with the N+ layer, and forming a P-type layer on the back side of the N-type semiconductor substrate; preparing a back electrode on the surface of the all aluminum back field; sintering the back electrode at low temperature. The preparation method has the advantages that a full back field screen printing plate is adopted to print, and a good PN node is formed through high-temperature sintering, thereby improving the photoelectricity performance on the solar cell; the back electrode is prepared by the low-temperature sintering, and the problem that the traditional silver and aluminum back electrode can only be sintered at high temperature is solved; as the sintering depth of the back electrode is small, the influence on the PN node is avoided, the subsequent assembly welding can be carried out, and the mechanical property index of the assembly processing is met.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a method for preparing an all-aluminum-doped N-type solar cell. Background technique [0002] In recent years, solar cells have developed rapidly, and traditional P-type silicon solar cells occupy a large market. However, P-type silicon is usually doped with boron, and there will be a large number of boron-oxygen pairs in the P-type silicon solar cell, which makes the performance of the P-type silicon solar cell decay quickly. In contrast, N-type silicon solar cells are doped with phosphorus. Since there is no boron-oxygen pair, it can overcome the light-induced attenuation effect of P-type silicon solar cells. At the same time, it also has the ability to resist most metal ions (except gold ions ) pollution insensitivity, longer minority carrier lifetime and diffusion length and other advantages, therefore, N-type silicon solar cells have gradually become a r...

AI Technical Summary

Problems solved by technology

However, at the same high temperature, the sintering depth of silver-aluminum paste is greater than that of pure aluminum, and the doping of silver cannot form a PN junction. The process steps of the electric field will lead to the incomplete formation of the PN junction at the back electrode, which will cause serious leakage problems in the entire device

Furthermore, if the full back field screen is used to print the back electric field first and then the back electrode, then after subsequent high-temperature sintering, it will not be able to be welded to form a battery module

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