Single InGaN nanocolumn spectroscopy

We report on the spectroscopy of single InGaN/GaN nanocolumns that are site-controlled nanostructures allowing for pixel-like large-scale integration. A single nanocolumn shows several narrow photoluminescence peaks at around 600 nm at 20–90 K, the linewidth of which ranges between 0.3 and 10 meV. We have observed an interesting temperature dependence of the integrated intensity, the maximum being around 40–70 K, which suggests the existence of efficient carrier injection channels from localized states. The results show that the optical properties of single nanocolumns are favorable for the future large-scale integration of single-photon emitters and qubits.