Ordered indium-oxide nanowire arrays and their photoluminescence properties

Ordered semiconductor ${\mathrm{In}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}$ nanowire arrays are uniformly assembled into hexagonally ordered nanochannels of anodic alumina membranes (AAMs) by electrodeposition and oxidizing methods. Their microstructures were characterized by x-ray diffraction, scanning electron microscopy, and transmission electron microscopy. A blue-green photoluminescence (PL) band in the wavelength range of 300–650 nm was observed in the ${\mathrm{In}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}\mathrm{/AAM}$ assembly system. The PL intensity and peak position depend on the annealing temperature, which is mainly attributed to the singly ionized oxygen vacancy in the ${\mathrm{In}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}$ nanowire array system.