Preparation method of polycrystalline black silicon of micro-nano composite suede structure

Abstract

The invention discloses a preparation method of polycrystalline black silicon of a micro-nano composite suede structure. The method comprises the following steps: imbedding polycrystalline silicon chips into etchant solution to obtain polycrystalline silicon chips with micro-meter suede structures; transferring the polycrystalline silicon chips with the micro-meter suede structures into a metal ion compound solution to deposit metal nanoparticles on the micro-meter suede; transferring into an etching solution to etch so as to obtain the polycrystalline silicon chips with the micro-nano composite suede structures; washing to remove metal particles residual on the surface; feeding into an alkaline solution to modify and etch the micro-nano composite suede structure; then drying to obtain the product. According to the method, the wet chemical etching method is carried out to prepare the micro-nano composite suede structure on the surface of the polycrystalline black silicone; such structure is extremely low in reflectivity; meanwhile, the preparation method is highly compatible with the general polycrystalline silicon suede preparation process; therefore, the preparation method can be quickly applied to the current general polycrystalline black silicon solar cell industry; the light absorbing efficiency can be obviously raised, and as a result, the efficiency of a solar cell is increased.

Description

technical field [0001] The invention relates to the technical field of manufacturing solar cell devices, in particular to a method for preparing polycrystalline black silicon with a micro-nano composite textured structure on the front surface of polycrystalline silicon. Background technique [0002] Polycrystalline silicon solar cells have occupied a dominant position in the current commercial solar cell products due to their comprehensive advantages in cost, conversion efficiency and electrical performance. However, there is a gap of about 1% between polycrystalline silicon cells and monocrystalline silicon cells in terms of conversion efficiency. Among them, the reflectivity of textured polycrystalline silicon is much higher than that of textured monocrystalline silicon, which is an important factor leading to this gap. Due to its extremely low reflectivity in the visible light range, black silicon has attracted widespread attention in the photovoltaic industry. Especiall...

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Problems solved by technology

[0004] At present, in the disclosed black silicon material production technology, patents on the preparation of black silicon by metal-catalyzed chemical etching, such as CN 102051618 A, CN 102768951 A and CN 103578966 A, are all directly processed on silicon wafers without textured structures. However, the obtained texture is only a single nano-texture, and no polycrystalline black silicon with a micro-nano composite texture structure has been prepared. The surface area and anti-reflection effect of the texture of the polycrystalline silicon wafer need to be improved; at the same time, the preparation of the texture The reaction process is carried out in one step in the etching solution, the reaction speed is fast, and the reaction process is not easy to control

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