Open Access Nano Express

Black silicon with self-cleaning surface prepared by wetting processes

Ting Zhang, Peng Zhang, Shibin Li*, Wei Li, Zhiming Wu* and Yadong Jiang

Author Affiliations

State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054, People's Republic of China

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Nanoscale Research Letters 2013, 8:351  doi:10.1186/1556-276X-8-351

Published: 13 August 2013

Abstract

This paper reports on a simple method to prepare a hydrophobic surface on black silicon, which is fabricated by metal-assisted wet etching. To increase the reaction rate, the reaction device was placed in a heat collection-constant temperature type magnetic stirrer and set at room temperature. It was demonstrated that the micro- and nanoscale spikes on the black silicon made the surface become hydrophobic. As the reaction rate increases, the surface hydrophobicity becomes more outstanding and presents self-cleaning until the very end. The reflectance of the black silicon is drastically suppressed over a broad spectral range due to the unique geometry, which is effective for the enhancement of absorption.

Keywords:
Black silicon; Metal-assisted wet etching; Hydrophobic surface; Reflectance; Absorption