Three-dimensional array of highly oriented crystalline ZnO microtubes

A scheme for the soln. growth of a highly oriented microtubular array of ZnO onto substrates is presented. The structural surface metastability of the polar surface is used to design corresponding hollow structures. Well-aligned single cryst. hexagonal tube (1-2 μm in width, 10 μm in length) with well-defined crystallog. faces were grown along the [100] direction and oriented perpendicular on the substrate in very large uniform arrays. Application of these ZnO microtubes are discussed.