Droplet epitaxy of zinc-blende GaN quantum dots

摘要

Zinc-blende GaN quantum dots were grown on 3C-A1N(0 0 1) by a vapor-liquid-solid process in a molecular beam epitaxy system. We were able to control the density of the quantum dots in a range of 5 × 10~8- 5 × 10~(12)cm~(-2). Photoluminescence spectroscopy confirmed the optical activity of the GaN quantum dots in a range of 10~(11)-5 × 10~(12) cm~(-2). The data obtained give an insight to the condensation mechanism of the vapor-liquid-solid process in general, because the GaN quantum dots condense in metastable zinc-blende crystal structure supplied by the substrate, and not in the wurtzite crystal structure expected from free condensation in the droplet.