Preparation method of selective emitter of crystalline silicon solar cell

Abstract

The invention discloses a preparation method of a selective emitter of a crystalline silicon solar cell. The preparation method comprises the following steps of preparing a borosilicate glass film of which the boron atom doping concentration is greater than or equal to 1E21 atoms/cm <3> on the surface of a silicon substrate; carrying out local doping on the borosilicate glass film in the metal contact area on the surface of the silicon substrate by adopting laser; and performing high-temperature annealing on the locally doped silicon substrate to complete the preparation of the selective emitter of the crystalline silicon solar cell. According to the preparation method disclosed by the invention, the borosilicate glass film with high doping concentration is prepared on the surface of the silicon substrate, and then the selective emitter of the crystalline silicon solar cell with better performance is prepared through laser selective doping and high-temperature annealing treatment, so that the photoelectric conversion efficiency of the crystalline silicon solar cell is remarkably improved; meanwhile, the preparation method also has the advantages of simple process, convenience in operation, easiness in control and the like, can be used for preparing by directly utilizing an existing device, and is high in suitability and is convenient for industrial utilization.

Description

technical field [0001] The invention belongs to the field of solar cells, and relates to a method for preparing a selective emitter of a crystalline silicon solar cell. Background technique [0002] Boron diffusion is widely used in the field of solar cells. In the preparation of high-efficiency cells such as Tunneling Oxide Passivated Contact (TOPCon) cells and Passivated Emitter Back Local Diffusion (PERL) cells, boron diffusion needs to be carried out on the front surface of silicon wafers. Boron diffusion creates a p-n junction. Conventional boron diffusion uses boron tribromide or boron trichloride, both of which will corrode the quartz parts; long-term operation will cause damage to the quartz parts and increase the operating cost of the equipment. In addition, with boron diffusion, the doping concentration of the surface borosilicate glass is only 1E 19 atoms / cm 3 Due to the low doping concentration, it is difficult to form a selective emitter, or it is difficult ...

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Problems solved by technology

Conventional boron diffusion uses boron tribromide or boron trichloride, both process gases will cause corrosion to the quartz parts; long-term operation will cause damage to the quartz parts and increase the operating cost of the equipment

In addition, with boron diffusion, the doping concentration of the surface borosilicate glass is only 1E 19 atoms / cm 3 Due to the low doping concentration, it is difficult to form a selective emitter, or it is difficult to reduce the contact resistance and metal recombination in the heavily doped region, which is not conducive to improving the open circuit voltage; at the same time, due to the low doping concentration, it cannot effectively improve The Auger recombination and short-wave quantum efficiency in the lightly doped region are not conducive to improving its short-circuit current, so that the effect of the selective emitter on improving the conversion efficiency of solar cells is not obvious

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