Polycrystalline silicon thin film containing silicon-oxygen nanocrystalline layer and preparation method and application of polycrystalline silicon thin film

Abstract

The invention discloses a polycrystalline silicon thin film containing a silicon-oxygen nanocrystalline layer, which comprises a tunneling layer positioned on the back surface of a substrate, a doped polycrystalline silicon layer positioned on the back surface of the tunneling layer, a sintered electrode positioned on the back surface of the doped polycrystalline silicon layer, and a first silicon-oxygen nanocrystalline layer positioned between the doped polycrystalline silicon layer and the sintered electrode. According to the polycrystalline silicon thin film containing the silicon-oxygen nanocrystalline layer, the doped silicon-oxygen nanocrystalline layer is added to serve as a barrier layer for diffusion of electrode metal, the polycrystalline silicon layer is prevented from being burnt through in the sintering process of metal slurry to make direct contact with crystalline silicon, and diffusion of the electrode metal to a substrate is blocked; the invention further provides a preparation method and application of the polycrystalline silicon thin film containing the silicon-oxygen nanocrystalline layer, an annealing crystallization process in preparation of a tunneling layer and a doped polycrystalline silicon layer and a high-temperature sintering process in preparation of a sintered electrode are combined into a whole, and the cost is reduced; and the polycrystalline silicon thin film containing the silicon-oxygen nanocrystalline layer is applied to a solar cell, and the cell efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of solar cells, more specifically, to a polysilicon film containing a silicon-oxygen nanocrystal layer, a preparation method and application thereof. Background technique [0002] With mature technology and low cost, crystalline silicon solar cells still occupy more than 95% of the photovoltaic market. A finished solar cell must have metal electrodes to collect carriers. However, the direct contact between metal and crystalline silicon will cause a higher density of defect states, and the recombination current is very large, which limits the efficiency of the cell. PERC cells reduce the contact area between metal and crystalline silicon to reduce the existence of defect states through the dielectric film + opening method; the passivation contact technology in recent years completely avoids the problem of contact between metal electrodes and crystalline silicon. For example, TOPCon technology, through ultra-...

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Problems solved by technology

[0005] (2) During the sintering process, the aluminum paste will corrode downward, and the thickness of the polysilicon layer is usually tens to hundreds of nanometers. The aluminum paste is very easy to pass through the polysilicon and directly contact the crystalline silicon. As mentioned above, the metal and the crystalline silicon directly contact each other. The contact will form a high density of defect states, resulting in a very large recombination current, which seriously degrades the passivation quality

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