Optical and electrical characterization of well-aligned ZnO rods electrodeposited on stainless steel foil

Aligned ZnO nanorods grown on polycrystalline substrates have promising optoelectronic applications. Novel samples with such structures were electrodeposited on stainless steel foil from a ZnCl2 route. Well-aligned and free-standing hexagonal nanorods with 100-nm diameter and closely packed microrods with a diameter above 1 μm could be grown normal to the substrate. The optical transition energies (absorption and emission) of samples were determined by transmittance and photoluminescence spectroscopy. We report, for the first time, the fabrication of high-quality Ag Schottky diodes formed on the oxygen-treated (002) facets of electrodeposited microrods. Diodes with a large barrier height (1.2 eV), low saturation current density (1.3 pA/cm2) and high rectification factor (5×106 at ± 3 V) were achieved. The concentration and mobility of free electrons in oxygen-treated microrods were measured as 1.4×1014 cm-3 and 1.2 cm2 V-1 s-1, respectively.