Boron-doped selective emitter and preparation method thereof, and boron-doped selective emitter battery

Abstract

The invention discloses a preparation method of a boron-doped selective emitter, which comprises the following steps of preparing a heavily doped region and a lightly doped region on the surface of a textured silicon wafer, covering a layer of boron dopant on the surface of the silicon wafer, and enabling the coverage area of the boron dopant to be not smaller than the area of the heavily doped region, carrying out laser doping on the boron dopant in the heavily doped region to form silicon boride, then carrying out high-temperature propulsion on the silicon boride to form a heavily doped region, forming a lightly doped region on the surface of the silicon wafer, and preparing the boron-doped selective emitter. According to the method, the silicon boride is formed through laser doping, the silicon boride is propelled at high temperature to form the heavily-doped region, the used laser is low in power and friendly to the textured surface of the silicon wafer, and the heavily-doped region is prepared while the light trapping effect of the textured surface of the silicon wafer is guaranteed; An alkali liquor or acid liquor cleaning process is added after the laser doping process, so that the residual boron dopant and attached impurities on the surface of the silicon wafer are well removed, and the minority carrier lifetime of the silicon wafer is not reduced.

Description

technical field [0001] The invention relates to a selective emitter and a preparation method, in particular to a boron-doped selective emitter, a preparation method and a boron-doped selective emitter battery. Background technique [0002] In the field of crystalline silicon solar cell technology, selective emitter is a relatively mature technology to improve cell performance. At present, the use of phosphosilicate glass (PSG) laser doping technology to prepare selective emitters for large-scale p-type cells has become a standard process scheme. However, the preparation technology of the selective emitter of the current n-type battery has not been very mature, as follows: [0003] First of all, the boron-doped selective emitter prepared by borosilicate glass (BSG) laser doping method cannot achieve the effect that phosphorus-doped selective emitter can achieve by the phosphosilicate glass (PSG) laser doping method. There are two reasons. One is that the equilibrium concent...

AI Technical Summary

Problems solved by technology

There are two main reasons for the high preparation cost of this method: first, the cost of ion implantation equipment is generally high and the maintenance cost is high; on the other hand, the heavily doped region of the boron-doped selective emitter requires higher quantity, requires a longer single-chip process time, and increases the equipment investment per unit of production capacity

Excessive production costs are contrary to the concept of solar cell grid parity

[0008]The above preparation methods of boron-doped selective emitter limit the technical development of n-type battery selective emitter to a certain extent