Biomimetic hierarchical ZnO structure with superhydrophobic and antireflective properties

A two step method, with a combination of top-down and bottom-up approaches, was developed for the fabrication of ZnO based hierarchical structures with nanorods on microcraters. A layer of well c-axis aligned, transparent, conductive ZnO thin film was deposited by pulsed DC sputtering on a Corning glass substrate. The microcraters were created with anisotropic etching on the as-deposited ZnO thin film. ZnO nanorods were then synthesized onto the etched film by means of metal organic chemical vapor deposition. The resulting hierarchical film exhibits a high water contact angle (>160°) with a low contact angle hysteresis (2°) and low reflection over a wide spectral range. This biomimetic material may find potential applications in many industrial fields, e.g., self-cleaning, solar cells, displays.

Graphical abstractA two step method creates ZnO hierarchical structure mimicking the lotus leaf surface, which shows high water contact angle.Figure optionsDownload full-size imageDownload high-quality image (46 K)Download as PowerPoint slideResearch highlights► Simple method to develop ZnO based lotus-like structures without using lithography. ► High water contact angle (>160°) with a low contact angle hysteresis (2°). ► Low reflection over a wide spectral range. ► Potential applications in many industrial fields, e.g., self-cleaning, solar cells, displays.