Spatially controlled, nanoparticle-free growth of InP nanowires

A technique for the growth of InP nanowires, which does not rely on the vapor–liquid–solid growth mechanism, is demonstrated using selective-area chemical beam epitaxy. The nanowires are precisely positioned on an InP wafer and are always aligned along the available substrate 〈111〉A directions. They have diameters as small as 40 nm, and typical lengths of 600 nm. They are found to be optically active, with thin embedded InAs layers showing quantum-dot-like behavior with well-defined excited states.