Novel growth of ZnO micro-rod arrays using hydrophobically micropatterned surfaces

Large-area ZnO micro-rod arrays were successfully achieved on a patterned glass substrate in an aqueous solution at mild growth conditions. Self-assembled monolayers (SAMs) of octadecyltrichlorosilane (OTS, C18H37SiCl3) were prepared on a glass substrate through micro-contact printing (μCP) technique. Site-selective ZnO growth was achieved by the patterned SAM-covered substrate. X-ray diffraction (XRD) and scanning electronic microscopy (SEM) were used to analyze as-fabricated ZnO arrays. ZnO micro-rods have a uniform diameter of about 300 nm with an aspect ratio of 15. It is noteworthy that the alkyl end-groups of OTS strongly directed the nucleation and growth of ZnO, and ZnO arrays were crystallized on organic group-covered regions. By modifying the μCP process, patterns that differ from the original PDMS stamp could be obtained.