Ordered n-type ZnO nanorod arrays

Using indium as catalyst for growth and simultaneously as doping source, ordered arrays of $n$ -type ZnO single crystal nanorods have been perpendicularly grown on $p\text{-}\mathrm{Ga}\mathrm{N}∕{\mathrm{Al}}_2{\mathrm{O}}_3$ substrates with a vapor phase transport growth method. The low temperature photoluminescence measurements of the $n\text{-}\mathrm{Zn}\mathrm{O}$ nanorods show dominant In-related neutral donor bound exciton emission in the ultraviolet region. Electrical transport measurements performed on single $n\text{-}\mathrm{Zn}\mathrm{O}$ nanorods yield resistances of about $50–200\mathrm{k}\Omega$ and a typical specific resistivity of $2.0\times {10}^{-2}\Omega \mathrm{cm}$ . The resistivity is one order of magnitude reduced by introducing In compared to the nominally undoped ZnO nanorods.