N-type MWT solar cell and preparation method thereof

Abstract

The invention discloses an N-type MWT solar cell and a preparation method thereof, and relates to the technical field of solar cells. The N-type MWT solar cell comprises an N-type silicon substrate, wherein the N-type silicon substrate is provided with through holes; a P-type emitter junction region is arranged on the front surface of the N-type silicon substrate; metal contact electrodes are guided to the back surface of the N-type silicon substrate through the through holes; a non-back field N-type silicon substrate region is arranged on the periphery of each through hole on the back surface of the N-type silicon substrate; the surface of a phosphorus back field and the surfaces of the non-back field N-type silicon substrate regions are basically on the same plane; an antireflection film layer is arranged on the front surface of the N-type silicon substrate, the surfaces of the non-back field N-type silicon substrate regions, the surface of the phosphorus back field and the inner walls of the through holes; and the ends, on the back surface of the N-type silicon substrate, of the metal contact electrodes and the surface of the antireflection film layer are in contact. By the preparation method of the solar cell, damages and impurities due to the fact that the MWT solar cell is prepared by a laser ablation process are omitted; the photoelectric conversion efficiency of the solar cell is improved; the preparation technology of the method is simple; and cost control is facilitated.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to an N-type MWT solar cell and a preparation method thereof. Background technique [0002] The metal-through battery is referred to as MWT battery, which is a battery in which both the emitter contact electrode and the base contact electrode are located on the back of the battery, that is, both the positive and negative electrodes are located on the back of the battery. In the N-type MWT battery structure, the contact electrode of the emitter on the light-receiving surface of the battery is guided to the back of the battery by the silicon matrix body, so that the current collected by the surface emitter flows out from the back of the battery, and the electrodes of the emitter and the base are in a circle. Point form (Pad point), the electrodes of the emitter and the base area are asymmetrical and alternately distributed in the form of dots. Generally, the positive electrode con...

AI Technical Summary

Problems solved by technology

However, when using laser ablation, the high temperature radiation of the laser will damage the silicon material, and there are a large number of recombination centers in the damaged layer, which reduces the life of photogenerated carriers, leads to increased leakage current, and affects the photoelectric conversion efficiency of the cell.

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