Formation of Hierarchical Pyramid-structured Si with Nanoholes by Using Thermally Dewetted Ag Thin Films


Si surface texturing generally requires an etching process to improve the anti-reflection and the self-cleaning properties of the surface. Among the various etching techniques for surface texturing, the wet etching method has been widely adopted as a relatively simple and inexpensive manufacturing method. In this study, we report the effects of hierarchical pyramid-structured Si with nanoholes formed using a chemical wet etching process with thermally dewetted Ag thin films. First, alkaline etching was performed on a Si wafer to fabricate micrometer-sized random pyramid structures. Then, Ag thin film was thermally grown on the pyramid-structured Si. Finally, nanopores were formed on the random pyramid structure via metal-assisted chemical etching. The final morphology of Si was a hierarchical random pyramid structure with nanoholes, exhibiting both anti-reflection and superhydrophobicity. The average reflectance decreased to ∼4%, and the contact angle increased to 170.5°, allowing these surfaces to be used in various wettability-controlled optoelectronic devices, such as Si solar cells for where light trapping and self-cleaning are essential.

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This research was supported by Korea Electric Power Corporation (R19XO01-11). This work was also supported by the BB21+ project in 2020.

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Correspondence to Hyo Jung Kim.

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Lee, H., Kim, H.J. Formation of Hierarchical Pyramid-structured Si with Nanoholes by Using Thermally Dewetted Ag Thin Films. J. Korean Phys. Soc. 77, 598–604 (2020).

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  • Anti-reflection
  • Superhydrophobic
  • Metal-assisted chemical etching
  • Thermally dewetted Ag