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.

中文翻译：

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使用热去湿银薄膜形成具有纳米孔的分层金字塔结构硅

Si表面纹理化通常需要蚀刻工艺以提高表面的抗反射和自清洁性能。在用于表面纹理化的各种蚀刻技术中，湿蚀刻法作为一种相对简单且成本低廉的制造方法已被广泛采用。在这项研究中，我们报告了使用化学湿蚀刻工艺与热去湿的 Ag 薄膜形成纳米孔的分层金字塔结构 Si 的影响。首先，在硅晶片上进行碱蚀刻以制造微米级的随机金字塔结构。然后，在金字塔结构的 Si 上热生长 Ag 薄膜。最后，通过金属辅助化学蚀刻在随机金字塔结构上形成纳米孔。Si的最终形态是具有纳米孔的分层随机金字塔结构，表现出抗反射和超疏水性。平均反射率降低至 4%，接触角增加至 170.5°，使这些表面可用于各种润湿性控制的光电器件，如硅太阳能电池，其中光捕获和自清洁是必不可少的。