Method for preparing single crystal silicon velvet surface

Abstract

The invention discloses a method for preparing a single crystal silicon velvet surface, comprising the following steps: corroding a single crystal silicon piece by alkali corrosion solution; and corroding and preparing the single crystal silicon velvet surface by acid corrosion solution. The alkali corrosion solution is mixed solution which comprises sodium hydroxide, sodium silicate, isopropanol and water, wherein the concentration range of the sodium hydroxide is 0.1-0.5 mol / L, the concentration range of the sodium silicate is 0.01-0.07 mol / L, and the concentration range of the isopropanol is 0.7-2.0 mol / L; the acid corrosion solution is mixed solution which comprises hydrofluoric acid, nitric acid and water, the concentration range of the hydrofluoric acid is 1-10 mol / L, and the concentration range of the nitric acid is 3-30 mol / L. The electricity leakage of a single crystal battery is smaller than the electricity leakage of the normal alkali velvet battery, thereby the conversion efficiency of a single crystal silicon solar battery is increased, and the power of the single crystal silicon assemblies is improved.

Description

Technical field: [0001] The invention relates to a method for preparing monocrystalline silicon textured surface. Background technique: [0002] The effective textured structure helps to improve the performance of solar cells, mainly reflected in the improvement of short-circuit current (Isc). The surface of single crystal silicon is etched by dilute KOH or NaOH alkali solution to prepare a uniform pyramid textured structure. However, the crystal plane structure on the surface of polysilicon is randomly distributed, which makes the alkali solution corrosion not very effective for polysilicon. Alkaline corrosion will also produce steps and cracks due to the different reaction rates between different grains on the polysilicon surface. [0003] For alkaline etching solution, the etching rate of each crystal plane of single crystal silicon is very different. Common low-index facets in single crystal silicon. The (100) plane is just one side of the cube in the figure, and it ...

AI Technical Summary

Problems solved by technology

If the etching time is too long, the size of the texture will become too large, dislocations and grain boundary morphology will appear, which will lead to a decrease in the mechanical properties of the silicon wafer, and can also cause leakage current problems in solar cells.

[0006] In production, the "pyramid" of the normal alkali-made monocrystalline textured surface is relatively large. During the production process, due to continuous transportation, the spire is damaged, resulting in relatively large leakage current after the finished battery, which affects the efficiency and the battery layer. Pressure, packaged into components, component power is much reduced

Images