350425.fig.006a
(a)
350425.fig.006b
(b)
Figure 6: (a) Schematic configuration of the vapor-phase growth of ZnO rods via the combination of the ledge mechanism and diffusion processes, which involves the surface diffusion-controlled mechanism nearby the growing steps and the gas phase diffusion-controlled mechanism nearby the solid-vapor interface. The concentration profile for the surface diffusion-controlled growth mechanism is shown in (b).