In Situ Fabrication of Density-Controlled ZnO Nanorod Arrays on a Flexible Substrate Using Inductively Coupled Plasma Etching and Microwave Irradiation

We have fabricated density-controlled ZnO nanorod arrays on a flexible substrate (Teflon) using inductively coupled plasma (ICP) etching with anodic aluminum oxide (AAO) membranes and microwave irradiation without using a catalyst at 90 degrees C. The average interpore distances of Si surface etched with an AAO membrane anodized in 0.3 M oxalic acid (Mask 1) and an AAO membrane anodized in 0.1 M phosphoric acid (Mask 2) were similar to 100 nm (Si pore density, similar to 1.86 x 10(10)/cm(2)) and similar to 450 nm (Si pore density, similar to 7.16 x 10(8)/cm(2)), respectively. During the microwave irradiation, ZnO nanorods grew from the Si pores. Thus, we could control the ZnO nanorods density by changing the interpore distance of the AAO membrane mask (Mask I case, similar to 1.34 x 10(10)/cm(2) and Mask 2 case, similar to 6.12 x 10(8)/cm(2)).