Surface passivated pure Indium Oxide nanowires for gas sensors

Indium oxide (In$_{2}$O$_{3})$ nanowires have applications in semiconductor electronics and gas sensing. We report on growth of stoichiometric In$_{2}$O$_{3}$ nanowires with diameter ranging from 40 to 80nm and lengths over 10 $\mu $m. Structural characterization done with SEM, XRD and TEM shows that the nanowires exhibits BCC structure and grow along the (100) direction. Energy Dispersive X-ray spectroscopy shows stoichiometric composition. Transport measurements on a single nanowire shows ohmic behavior and a resistance of about 100 K$\Omega $. Photoluminescence spectrum at room temperature shows strong emission peaks at 370nm and 415nm, corresponding to near band edge and defect related emission respectively. We present a technique of post-growth annealing of these nanowires to eliminate the defect induced emission and enhance band edge emission. Passivating the surface of these nanowires enhances their gas sensing abilities.