Monolithic single GaN nanowire laser with photonic crystal microcavity on silicon

Optically pumped lasing at room temperature in a silicon based monolithic single GaN nanowire with a two-dimensional photonic crystal microcavity is demonstrated. Catalyst-free nanowires with low density (∼108 cm-2) are grown on Si by plasma-assisted molecular beam epitaxy. High resolution transmission electron microscopy images reveal that the nanowires are of wurtzite structure and they have no observable defects. A single nanowire laser fabricated on Si is characterized by a lasing transition at λ=371.3 nm with a linewidth of 0.55 nm. The threshold is observed at a pump power density of ∼120 kW/cm2 and the spontaneous emission factor β is estimated to be 0.08.