Electrical and photoconductive properties of vertical ZnO nanowires in high density arrays

High density vertical zinc oxide nanowire arrays were fabricated using highly ordered channels in anodic alumina membranes via chemical vapor deposition assisted by electrochemical deposition methods. Using conductive atomic force microscopy, the electrical transport and photoconduction of individual vertical nanowires were investigated. A negative photoconductivity was observed as a result of electron trapping in the alumina membrane. In contrast, positive photoconductivity was observed using a thermally annealed anodic alumina membrane as the nanowire growth template. These studies provide a pathway for constructing highly integrated nanoscale electronic and optoelectronic circuits, such as logic circuits, light emitting diodes, solar cells, and ultrahigh resolution imaging sensors.