Diffusion method for solace cell with polycrystalline silicon selective emitter

Abstract

The invention discloses a diffusion method for a solar cell with a polycrystalline silicon selective emitter. The diffusion method includes the following steps: firstly, placing a silicon chip on which a doping agent grows into a diffusion furnace and raising the temperature to 750-800DEG C, wherein the environment in the furnace is N2 with the flow being 10-30slm; secondly, after the temperature is stabilized, uniformly raising the temperature in each temperature zone in the furnace to 850-900DEG C, introducing 0.2-2slm of N2 carrying trichloroethane, 1-5slm of O2 and 10-30slm of N2 while raising the temperature so as to realize heavy doping and controlling the heavily-doped sheet resistance between 30 and 60 omega / m<2>; thirdly, reducing the temperature of each temperature zone to the diffusion temperature of 820-840DEG C and introducing N2 carrying POCl3 for diffusing; fourthly, reducing the temperature of each temperature zone to 780-800DEG C, stopping introducing the N2 carrying the POCl3 so as to realize shallow doping, wherein the propulsion time is 10-25minutes and controlling the shallow-doped sheet resistance between 70-120 omega / m<2>; and fifthly, cooling the silicon chip, taking out the silicon chip and finishing the diffusion process. According to the diffusion method disclosed by the invention, the diffusion of a doping agent is realized at high temperature and the heavy doping and shallow doping of the selective emitter are realized; and meanwhile, the gettering of a polycrystalline silicon is realized, so that the conversion efficiency is greatly increased.

Description

technical field [0001] The invention relates to a diffusion method for a polysilicon selective emitter solar cell, which belongs to the technical field of solar energy. Background technique [0002] A solar cell, also known as a photovoltaic cell, is a semiconductor device that converts the sun's light energy directly into electrical energy. Because it is a green product, does not cause environmental pollution, and is a renewable resource, solar cells are a new energy source with broad development prospects in today's energy shortage situation. At present, photovoltaic scientists have explored a variety of new battery technologies, metallization materials and structures to improve battery performance and increase their photoelectric conversion efficiency: surface and bulk passivation technology, Al / P gettering technology, selective emission region technology, dual Layer anti-reflection coating technology, etc. [0003] At present, selective emitter technology is also one o...

AI Technical Summary

Problems solved by technology

[0005] However, at present, when preparing polysilicon selective emitter solar cells, gettering and diffusion are generally divided into two steps, so the process is more complicated and the cost is higher