Passivated contact N type back junction solar cell and preparation method thereof

Abstract

The invention aims to disclose a passivated contact N type back junction solar cell and a preparation method thereof. The passivated contact N type back junction solar cell comprises an N type crystalsilicon wafer, wherein an N + front surface field doped region, a front surface passivation antireflection layer and a metal contact electrode are sequentially arranged on the front surface of the Ntype crystal silicon wafer from inside to outside, and a tunneling oxide layer, a P + doped polycrystalline silicon region, a back surface passivation antireflection layer and a metal contact electrode are sequentially arranged on the back surface of the N type crystal silicon wafer from inside to outside. Compared with the prior art, the passivated contact N type back junction solar cell of the invention has the following characteristics that P + doped polycrystalline silicon is applied to the back surface of the N type cell and is used for passivating an emitter junction and a metal contactregion, carrier enters the doped P type polycrystalline silicon layer through the tunneling oxide layer to achieve selective transmission and collection, surface recombination, especially metal contact area recombination, of an emitter junction is greatly reduced by means of the excellent passivation performance of polycrystalline silicon, the open-circuit voltage and efficiency of the cell are improved, and the purpose of the invention is achieved.

Description

technical field

[0001] The invention relates to a solar cell and a preparation method thereof, in particular to an N-type back-junction solar cell with a passivation contact and a preparation method thereof. Background technique

[0002] Compared with P-type silicon, N-type silicon has a higher minority carrier lifetime and no light-induced attenuation effect, which has gradually become the focus of research structures and photovoltaic companies. At present, the common N-type structure is that the front is a P+ emitter junction, the substrate is an N-type silicon, and the back is an N+ back surface field. Generally, the P+ diffusion layer adopts the stacked structure of SiO2 / Al2O3 / SiNx, and the N+ back surface field adopts the stacked structure of SiO2 / SiNx as the passivation layer, and then uses the burn-through paste to form an ohmic contact with the substrate. The metallization based on the fire-through paste technology will destroy the passivation film under the metal, ...

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