Fig. 2
Various nanostructured thin films by OAD. Cross-sectional and top-view SEM images of various nanostructured films fabricated by OAD. Scale bar = 500 nm. a SnO2 zigzags, b TiO2 helixes, c Al vertical posts, and d WO3 helixes grown on ZnO pre-patterns by nanoimprint lithography. e Top-view SEM image of WO3 helixes grown on pre-patterned substrate. Inset shows top-view SEM image of pre-patterned ZnO by nanoimprint lithography. f WO3-SiO2-WO3 hetero-NHs