The nanorods grow epitaxially on both Si (100)
and sapphire (0001) substrates. The interface of ZnO
(0002) nanorod with Si (100) substrate has been investigated
by Wu and Liu[25] using high resolution transmission
electron microscopy and electron energy-loss
spectroscopy. It has been found that the ZnO (0002)
plane can grow parallel to Si (100) plane with formation
of a thin SiOx interfacial layer. In addition,
on Si substrate, we have observed that the nanorods
have a reduced diameter at the top portion and connected
to the base rod through a faceted neck formation
(Fig. 9 (a))