Tubular perc single-sided solar cell and its preparation method and special equipment

Abstract

The invention discloses a tubular PERC single-sided solar cell, which comprises a back silver main grid, an all-aluminum back electric field, a back composite film, a P-type silicon, an N-type emitter, a front passivation film and a front silver electrode; The film includes one or more of aluminum oxide film, silicon dioxide film, silicon oxynitride film and silicon nitride film, and is deposited on the back of the silicon wafer by using tubular PECVD equipment. There are four gas pipelines for silane, ammonia, trimethylaluminum, and laughing gas. The device for loading and unloading silicon wafers of the tubular PECVD equipment is a graphite boat, and the depth of the stuck groove of the graphite boat is 0.5-1mm. The invention also discloses a preparation method and special equipment for a tubular PERC single-sided solar cell. By adopting the invention, the photoelectric conversion efficiency is high, the appearance yield rate and EL yield rate are high, and the problems of scratches and winding plating are solved.

Description

technical field [0001] The invention relates to the field of solar cells, in particular to a tubular PERC single-sided solar cell, a preparation method and special equipment for the tubular PERC single-sided solar cell. Background technique [0002] Crystalline silicon solar cell is a device that effectively absorbs solar radiation energy and converts light energy into electrical energy by using the photovoltaic effect. Under the action, holes flow from the N region to the P region, electrons flow from the P region to the N region, and a current is formed after the circuit is turned on. [0003] Traditional crystalline silicon solar cells basically only use front passivation technology, depositing a layer of silicon nitride on the front of the silicon wafer by PECVD to reduce the recombination rate of minority carriers on the front surface, which can greatly increase the open circuit voltage and short circuit of crystalline silicon solar cells current, thereby improving the...

AI Technical Summary

Problems solved by technology

Tubular PECVD coating has two disadvantages: 1. During the insertion process, the silicon wafer will rub against the graphite boat wall, resulting in scratches on the side of the silicon wafer next to the graphite boat wall

2. During the deposition process, due to the inevitable gap between the silicon wafer and the graphite boat wall, especially the large gap at the stuck point, the process gas will diffuse to the other side of the silicon wafer and form a film on the other side. , that is, winding plating, and the winding plating at the stuck point is more serious

2. There is no coating film on the back of the conventional battery, and the film layer around the edge of the back side is relatively thin, which does not look obvious and does not affect the appearance yield

[0009] However, using tubular PECVD to make the back film of the PERC battery, scratches and wrapping seriously affect the qualified rate of the finished battery. The problems are: 1. During the deposition process, the back film will wrap around the edge of the front side, because the PERC battery is Double-sided coating, the thickness of the coating on the front edge is thicker, resulting in boat marks and color difference on the front edge of the battery, which affects the appearance yield

2. During the process of inserting the wafer into the graphite boat, the front side of the silicon wafer will touch the graphite boat wall, and the PN junction on the front side will be scratched, resulting in scratches in the EL test and affecting the electrical performance of the battery

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