Epitaxial growth of winding ZnO nanowires on a single-crystalline substrate

Crystallographically oriented yet morphologically squiggly nanoscale ZnO architecture was produced through epitaxial growth by using a simple aqueous solution system. Specific adsorption of pyranine, an organic dye molecule having three sulfonic groups, suppressed regular growth in the c direction, and thus induced lateral growth of winding ZnO nanowires with diameters ranging from 20 to 100 nm on a single-crystalline ZnO (001) substrate. Although resultant wool-like structures consisted of tangled wires, the crystalline lattice of the whole architecture was found to be continuous and have six-fold symmetry originating from the single-crystalline substrate.