One-step wet process black silicon preparation and surface treatment method

Abstract

The invention provides a one-step wet black silicon preparation and surface treatment method, which includes the following steps: immersing the silicon wafer after removing the surface damage layer into an etching liquid and reacting to prepare black silicon; the etching liquid is concentrated hydrogen containing metal ions. A mixed aqueous solution of hydrofluoric acid, oxidant and high molecular polymer; the black silicon is immersed in the surface treatment etching liquid for surface optimization treatment, thereby obtaining a silicon wafer with a uniform texture of sub-micron structure; wherein, the surface treatment etching liquid contains Mixed acid aqueous solution of additives. The wet black silicon preparation method provided by the invention is simple in process and low in cost. The etched black silicon suede surface is uniform without sharp edges and has a reflectivity of 7-15%. This method greatly improves the absorption of light by silicon cells. Efficiency, solar cells made from black silicon produced by this method have lower cell leakage rate, stable open circuit voltage, and higher 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.

Images