Alkali-polishing efficient PERC battery and preparation process thereof

Abstract

The invention discloses a preparation process of an alkali-polishing efficient PERC battery. The preparation process comprises the following steps: step S01, texturing; step S02, diffusing; step S03,SE process; step S04, thermal oxidation; step S05, removing PSG; step S06, alkali-polishing; step S07, annealing; step S08, back passivating; step S09, back film; step S10, front film; step S11, laserslotting; and step S12, printing and sintering: accomplishing the back printing and the back printing through silk-screen printing, and then performing sintering process; step S13, electric injection: electric injection: through a light attenuation furnace or an electric injection furnace; and step S14, testing and sorting: performing battery testing and sorting on the cell. The invention furtherdiscloses an alkali-polishing efficient PERC battery. By adding the high-temperature thermal oxidation process flow after the SE, a layer of silicon dioxide protection layer is grown at the front SEregion at high temperature, a pyramid textured surface of the SE region is effectively protected, and the process flow can guarantee that the stable and continuous production of the SE alkali-polishedPERC battery.

Description

technical field [0001] The invention relates to the technical field of photovoltaic solar cells, in particular to an alkali-polished high-efficiency PERC cell and a preparation process thereof. Background technique [0002] PERC cell technology has obvious performance and cost advantages, promoting the application of P-type solar-grade monocrystalline silicon wafers. At the same time, high efficiency, low cost, and environmental protection are the mainstream directions for the development of crystalline silicon solar cells. PERC cells mainly form a passivation film on the back, which requires the back surface to have good flatness. The main research of alkali polishing equipment focuses on polishing the back, which not only solves the problem of flatness of the back coating, but also can Remove the N-type diffusion layer on the back, promote the formation of the P+ layer, improve the minority carrier lifetime, and increase the reflectivity of the back surface. Therefore, t...

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Problems solved by technology

[0004] For the alkali throwing technology and SE technology, it can be concluded that PERC battery technology still has obvious defects in the existing technology: 1. The conventional route of the existing SE technology is matched with acid etching, and a large amount of sulfuric acid, Nitric acid, hydrofluoric acid, hydrochloric acid, the post-treatment of waste liquid is complex, costly and not environmentally friendly; 2. The PERC battery preparation method based on the backside alkali polishing process with the application number "201710291360.5", uses a relatively cheap backside pickling machine and The trough-type back-polishing machine reduces cost investment, and the back of the battery in the alkaline polishing process is flatter than the conventional acid polishing, which is conducive to passivation and back contact, and the efficiency of the PERC battery produced is significantly improved. The protection of the SE area is poor, and the suede is prone to be polished during mass production, which destroys the PN junction of the SE area, resulting in unstable efficiency or leakage failure; 3. The suede is prone to appear during mass production The situation of polishing cannot guarantee the stable and continuous production of SE alkaline polished PERC cells

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