Single-crystalline ZnO nanowires grown on silicon wafers

We report electrodeposition of single-crystalline ZnO nanowires on Si wafers. Similar wires grown on conductive SnO2/glass substrates show excellent electro-luminescence with visible and ultra-violet spectral contributions. For high doping levels in the n-type Si substrates high-quality nanowires can be grown. For low electron concentrations occurring in weakly n-type wafers or in p-type wafers, nanowire growth is inhibited. For B-doped p-type samples the growth process can be improved by applying external bias light or more cathodic electrode potentials.