Solar cell manufacturing process and chained coating equipment

Abstract

The invention discloses a solar cell manufacturing process. The solar cell manufacturing process comprises the following steps: S1, cleaning and texturing; S2, boron diffusing; S3, cleaning to remove the BSG layer and polishing the back surface; S4, depositing a tunneling oxide layer and a doped amorphous silicon layer on the back surface; S5, preparing an aluminum oxide and silicon nitride laminated layer on the front side; S6, annealing; S7, depositing a silicon nitride anti-reflection protection layer on the back surface; and S8, carrying out silk-screen printing, sintering testing and sorting. According to the invention, the process of depositing aluminum oxide and silicon nitride films in the front surface is adjusted to be before the annealing process, and the passivation capability of aluminum oxide and silicon nitride is fully excited by using long-time high temperature during annealing, so that the cell efficiency is improved; and secondly, the front surface of the silicon wafer is covered with an aluminum oxide film and a silicon nitride film in advance, so that the situation that impurities are introduced into the front surface during annealing to affect the battery performance is avoided, meanwhile, the cleaning procedure after annealing can be omitted, the technological process is simplified to 8 steps from 9 steps in the prior art, and therefore the production efficiency is effectively improved.

Description

technical field [0001] The invention relates to the technical field of solar cell preparation, in particular to a solar cell manufacturing process and chain coating equipment. Background technique [0002] In the future, efficiency improvement and cost reduction will be the main direction of high-efficiency battery industry technology. Tunneling oxide passivation contact (TOPCon) technology is one of the key research directions of current industrialized high-efficiency solar cells, and its mass production efficiency has increased from 20.7% to 24% or even higher in the past three years. Based on the current cost calculation, for every 1% increase in TOPCon battery efficiency, the EPC cost will decrease by 0.2 yuan / W. It can be seen that the continuous improvement and optimization of TOPCon technology has become the key to further improving the overall efficiency of the battery and obtaining a lower LCOE. [0003] refer to figure 1 , the existing TOPCon cell manufacturing p...

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Problems solved by technology

[0004] 1. For TOPCon’s existing process flow, because the doped amorphous silicon layer on the back surface of the silicon wafer undergoes long-term high-temperature treatment during annealing, the escape and diffusion of doped phosphorus will occur, thereby polluting the front surface. Therefore, annealing After the process (step S5) is completed, a cleaning process (step S6) is required to remove the pollutants introduced from the front surface of the silicon wafer. The process is relatively complicated and there are many process steps, which affects the cell yield, production efficiency and cost;

[0005] 2. In the existing process, the front passivation structure of TOPCon, that is, the aluminum oxide and silicon nitride stack, is only subjected to short-term high-temperature treatment in the final printing and sintering process after deposition, but the short-term high temperature cannot fully activate its passivation capacity, becoming an important factor restricting the improvement of battery efficiency

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