GaN Nanocolumns on Si(111) Grown b Molecular Beam Epitaxy

GaN nanocolumns are reproducibly grown by plasma-assisted molecular beam epitaxy on Si(111). The nanocolumn density and diameter, 20–150 nm, are controlled by means of the III/V ratio. The nanocolumns grow parallel to the [111] direction of the Si substrate. The columns have been transferred to a Si(100) substrate covered with a layer of 300nm SiO2; single nanowire devices have been fabricated using finger shaped electrical contacts (Ti/Au) obtained by e-beam patterning technique. The electrical transport properties of the resulting metal–semiconductor–metal nanostructures are analyzed by means of current– voltage measurements with and without UV-illumination.