Electrical Properties Of Zno-Based Nanostructures

Single ZnO nanowires grown by vapor phase transport were contacted by Ti/Au electrodes patterned by using e-beam lithography. The current-voltage characteristics display a rectifying behavior, likely due to an interfacial insulating layer between the metal and the semiconductor. The contact resistance was determined to 85 M Omega, the deduced carrier concentration yields 10(15) cm(-3) which is low and hints towards Fermi-level pinning at surface states. Spectrally-resolved photoconduction measurements reveal an increase in current only for illumination with light at an energy above the band gap energy. Scanning electron micrographs of the metal-nanowire interface show a smearing of the electrodes; however, energy dispersive X-ray element maps could not expose the elemental composition of the blurry regions.