Alkaline texturing is still the state of the art for silicon-based solar cell technology leading to high efficiency of solar cells.   The sawed silicon wafers will be cleaned and afterwards the alkaline texturing process takes place. The texturing process will etch surface of silicon, that we obtain a surface with pyramids. This will reduce the reflection of the light to maximize the light absorption into the silicon material, leading to a higher efficiency of the solar cells.

Without any additive the surface of the silicon wafer will be etched in the alkaline process only planar, while additives influence the etching direction. With texturing additives like monoTEX® the anisotropic etching is preferred and we obtain a etched surface with homogenously distributed pyramids and a low reflection.

Texturing additives

RENA in-house development monoTEX® is the best-in-class type of moderating and wetting agent for alkaline texturing since 2008. RENAs texturing additive monoTEX® was the first IPA free additive which is non-flammable and operating at temperatures far below the boiling point of its components. Therefore this additive lead to an enhanced safety during production and also increased texture results in terms of bath stability, lower reflectivity and decreased chemical consumption.

monoTEX® texturing additive is nowadays used for alkaline etching with NaOH or KOH of as-cut silicon wafers of p-type or n-type. The etch removal and pyramid size can be easily adjusted by changing the process parameters (time, alkaline or additive concentration).

SVP Technology & Innovation
Dr. Holger Kühnlein
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