Figure 2

Catalyst-free (top) and Ni-catalyzed (bottom) InN nanorods grown onc-plane sapphire substrate. The images (SEM) were taken at various degrees of tilt (∼45°). Color was added to increase contrast. The nanorod placement is random, but the size is outstandingly uniform. The vertical alignment testifies to the existence of epitaxial relations between thec-plane sapphire substrate and the InN nanorods. Each nanorod is 1725-nm-high and 375-nm-wide on the average. Image width: top-left: 10.5 μm, top-right: 550 nm, bottom: 3.33 μm