Method for manufacturing monocrystalline silicon SE-PERC battery through secondary annealing

Abstract

The invention discloses a method for manufacturing a monocrystalline silicon SE-PERC battery through secondary annealing, and the method comprises the steps: texturing, diffusion, front laser, etching, annealing, rear surface passivation of a film, front surface passivation of a film, back laser, silk-screen printing, sintering, and testing, and is characterized in that a step of repairing damageannealing is added after the front laser step and before the etching step. A laser annealing step is carried out after the front laser step, and a silicon wafer is put into a tubular annealing furnaceto be annealed, so that the effect of repairing damage of the front laser to the surface of the silicon wafer is achieved, the surface is passivated, carrier recombination is reduced, and the open-circuit voltage and the short-circuit current of a crystalline silicon cell are improved.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to a method for manufacturing an infrared laser annealed single crystal silicon SE-PERC cell. Background technique [0002] With the rise of monocrystalline silicon SE-PERC cells, lasers are more widely used in the preparation of crystalline silicon cells. Laser slotting and selective emitter preparation are inseparable from lasers. Technologies such as Metal Wrap Back Contact (MWT) and Emitter Piercing (EWT) also require laser perforation. The traditional monocrystalline silicon SE-PERC cell manufacturing steps are: [0003] 1. Texture making: use wet technology to form a textured surface on the surface of the P-type monocrystalline silicon wafer; [0004] 2. Diffusion: P-N junction is formed by diffusion; [0005] 3. Front laser: Prepare selective emitter, and use laser to do heavy doping on the surface of silicon wafer; [0006] 4. Etching: use HF / HNO3 solution for back...

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Problems solved by technology

[0014] As far as monocrystalline silicon SE-PERC cells are concerned, during the process of selecting the emitter through the front laser step, the laser energy is in the form of a Gaussian distribution, and relatively heavy damage will occur in the area where the laser acts, which will destroy the original The lattice structure of the textured surface of the silicon wafer makes the carriers recombine near the surface defect state, which leads to the decrease of the opening voltage and short current of the crystalline silicon cell, and reduces the photoelectric conversion efficiency of the monocrystalline silicon SE-PERC cell

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