Local passivation contact IBC battery structure and preparation method thereof

Abstract

The invention discloses a local back passivation contact IBC solar cell, which comprises a P-type crystalline silicon substrate, and the back surface of the P-type crystalline silicon substrate sequentially comprises a tunneling oxide layer, back surface n + doped polycrystalline silicon regions, back surface slotting p + doped regions, a back surface passivation film and a back surface metal electrode from inside to outside, wherein the back surface n + doped polycrystalline silicon regions and the back surface slotting p + doped regions are alternately arranged; the front surface of the P-type crystalline silicon substrate is of a pyramid suede structure and sequentially comprises a front surface passivation film and an antireflection film; an emitter region on the back surface of the P-type crystalline silicon substrate adopts a tunneling oxide layer and an n + doped polycrystalline silicon passivation layer, the surface of the emitter region is passivated by an aluminum oxide and silicon nitride composite film or a silicon oxynitride film, a receiver region adopts local boron doping, and the surface of the receiver region is passivated by an aluminum oxide and silicon nitride composite film or a silicon oxynitride film; and according to the invention, the front electrode can be prevented from blocking light, the recombination rate of the back surface of the cell can be greatly reduced, the open-circuit voltage and the short-circuit current are improved, and the manufacturing cost of the solar cell is further reduced.

Description

technical field [0001] The invention relates to the technical field of solar cells, in particular to an IBC solar cell with partial back passivation contact and a preparation method thereof. Background technique [0002] A solar cell is a semiconductor device that can convert solar energy into electrical energy. Lower cost of electricity has always been the goal pursued by the solar cell industry. At present, the mainstream product in the industry is the P-type PERC crystalline silicon solar cell, and its efficiency is already close to the theoretical level of this structure, and there is little room for further efficiency improvement. The battery technology is simple, and the p+ doped region contact electrodes and the n+ doped region contact electrodes are respectively located on the front and back sides of the battery sheet. The front of the battery is the light-receiving surface, and the coverage of the metal contact electrodes on the front will inevitably cause a part o...

AI Technical Summary

Problems solved by technology

The front of the battery is the light-receiving surface, and the coverage of the metal contact electrodes on the front will inevitably cause a part of the incident sunlight to be blocked and reflected by the metal electrodes, resulting in a part of optical loss

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