One-step wet black silicon preparation and surface treatment method

Abstract

The invention provides a one-step wet black silicon preparation and surface treatment method, which comprises the steps of enabling a silicon wafer with a surface damage layer being removed to be immerged into a corrosive liquid so as to prepare black silicon through reaction, wherein the corrosive liquid is a mixed aqueous solution of a metal ion containing concentrated hydrofluoric acid, an oxidizing agent and a high-molecular polymer; and enabling the black silicon to be immerged into a surface treatment corrosive liquid so as to carry out surface optimization treatment, and acquiring a silicon wafer with a sub-micrometer structure and uniform texturing, wherein the surface treatment corrosive liquid is an additive containing mixed acid aqueous solution. The wet black silicon preparation method provided by the invention is simple in process and low in cost, the texturing surface of the black silicon after corrosion treatment is uniform and has no sharp boundary, and the reflectivity is 7-15%. The one-step wet black silicon preparation and surface treatment method greatly improves the absorption efficiency of a silicon cell for light, a solar cell prepared by using the black silicon prepared according to the method has low cell electric leakage rate, stable open-circuit voltage and high conversion efficiency.

Description

technical field [0001] The invention belongs to the field of solar cells, in particular to a one-step wet-process black silicon preparation and surface treatment method. Background technique [0002] The reflection of incident light on the surface of the silicon wafer greatly reduces the efficiency (current flow) of silicon solar cells. If the surface of the silicon cell is not treated with anti-reflection, about 40% of the sunlight will be lost. This antireflection effect must be effective across the entire solar spectrum and at a wide variety of incident light angles. [0003] Currently, antireflection on crystalline silicon photovoltaic cells is achieved through several different techniques. For monocrystalline silicon, anisotropic (pyramidal) texture etched silicon single crystals reduce reflectivity to about 5-15% above facing 100 monocrystalline silicon, but mainly at incident light angles close to 90° rather than reflection at low incidence angles At the same time,...

AI Technical Summary

Problems solved by technology

[0010] However, the suede obtained by the above methods has a mixed structure of micron and nanometers, which has limitations in terms of uniformity and electrical properties.

In particular, there are serious defects in the surface treatment of black silicon, which leads to a decrease in the open circuit voltage of the solar cell and an increase in leakage, which directly affects the direct application of the industry.

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