Passivation contact solar cell with selective emitter structure and preparation method of passivation contact solar cell

Abstract

The invention relates to a passivation contact solar cell with a selective emitter structure and a preparation method of the passivation contact solar cell. The method comprises the following steps: (1) preparing texturing surfaces on two surfaces of an N-type crystalline silicon substrate; (2) performing boron diffusion treatment on the texturing surface of the front surface of the substrate to form a lightly doped region layer; (3) performing local boron ion implantation on the lightly doped region layer by using a mask, and annealing to form a local heavily doped region; (4) preparing a tunneling oxide layer on the texturing surface of the back surface of the substrate, and preparing a phosphorus-doped polycrystalline silicon layer on the tunneling oxide layer; (5) preparing a silicon nitride antireflection layer on the phosphorus-doped polycrystalline silicon layer; preparing an aluminum oxide passivation layer on the lightly doped region layer on the front surface of the substrate, and preparing a silicon nitride antireflection layer on the aluminum oxide passivation layer; and (6) carrying out silk-screen printing of metallized slurry on the two surfaces of the substrate, andsintering. According to the invention, the composite current on the surface of the emitter can be remarkably reduced, so that the efficiency of the N-type passivation contact battery can be improvedby more than 0.2%.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to a passivated contact solar cell with a selective emitter structure and a preparation method thereof. Background technique [0002] The N-type battery uses N-type silicon as the substrate material, which has good resistance to metal impurity pollution and long minority carrier diffusion length. Compared with the traditional p-type battery, it has the advantages of no light-induced attenuation and higher battery efficiency. favored by the market. N-type passivated contact battery is a new type of N-type battery structure. Its tunneling passivation layer provides good surface passivation for the n+ surface, greatly reduces metal contact recombination, and improves the open circuit voltage and short circuit current of the battery. The cell efficiency of this structure is much higher than that of traditional crystalline silicon cell products, which is more conducive to reducing t...

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Problems solved by technology

[0003] The existing N-type passivated contact cell structure solves the passivation of the n surface, but the recombination of the emitter surface is still relatively high, which has become a bottleneck for efficiency improvement. To reduce the recombination of the emitter surface, it is necessary to take into account the passivation and contact resistance

[0004] Compared with phosphorus-doped emitters, since boron is much more difficult to activate than phosphorus, the selective doping of boron is still a difficult problem in the world, and there is no mass-producible selective emitter preparation method with both efficiency and yield. , such as laser doping, which is very mature in phosphorus selective doping, is still immature in boron doping

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