Hopping conduction in single ZnO nanowires

ZnO nanowires were synthesized by chemical vapour deposition (CVD). The dc electrical conductivity of a single ZnO nanowire was investigated over a wide temperature range from 300 to 6 K. It is found that the rho similar to T-1/2 temperature dependence of conductivity follows the relation In p similar to T-1/2. The conductivity data suggest that the dominant conduction mechanism is Efros-Shklovskii variable-range hopping conduction. The strong electron-electron interaction in the nanowire is also proved by the I-V and dI/dV curves, on which there emerges a Coulomb gap-like structure at low temperatures.