Electrical and photoresponse properties of Co3O4 nanowires

Electrical and photocurrent characteristics of single Co3O4 nanowire devices were studied systematically. Current-voltage characteristics' measurements and impedance spectroscopy of single Co3O4 nanowire devices were performed and analysed using possible mechanism. Photoresponses of individual nanowires were obtained by global irradiation of laser beams with photon energies above band gap and at sub-band gap of the nanowires. The magnitude of photocurrent and its response time revealed that defect level excitations significantly contribute to the photoresponse of Co3O4 nanowires. In addition, the electrically Ohmic nature of the nanowire/Pt contact and p-type conductivity of Co3O4 nanowire is extracted from the current-voltage characteristics and spatially resolved photocurrent measurements. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4712497]