(a) TEM image of a ZnO comb, showing the distinct arrays of teeth on one side. The inset is the SAED pattern taken from the stem ribbon. (b) TEM image of the root part of the teeth at higher magnification and the corresponding SAED pattern. (c) Schematic models of the comb-like structure observed by TEM. (d) A projection of wurtzite-type ZnO along direction highlighting its polar planes (001), (011), and (01).
