Room-temperature quantum-dot-like luminescence from site-controlled InGaN quantum disks

We studied the optical properties of site-controlled InGaN quantum disks fabricated by the top-down approach. Room-temperature quantum-dot-like photoluminescence was observed from a single InGaN quantum disk. Size-dependent emission wavelength shift was measured and attributed to the quantum confinement in the disk plane. Theoretical modeling was carried out to explain the large blue shift due to size quantization. Temperature dependent luminescence was characterized and showed an abnormally large linewidth at low temperature and a linewidth saturation above 100 K. A sidewall charge center model was proposed to explain these phenomena. (C) 2011 American Institute of Physics. [doi:10.1063/1.3672441]