Fig. 1: Photoluminescence characteristics of the SA GaN/AlN QD sample.

a 100 × 100 µm² micro-photoluminescence mapscan of the patterned sample for which the signal is recorded at 300 K and integrated between 2.5 and 4.5 eV. Spatially resolved micro-photoluminescence integrated intensity images are recorded using steps of one µm. The strongest signal is measured from unprocessed areas with a high QD density. Inset: Typical µ-PL spectrum collected from an unprocessed area (blue line) and from a mesa (red line). b Full width at half-maximum (FWHM) distribution of GaN/AlN excitonic emission recorded at low temperature (T = 5 K) in the cw low excitation regime. Orange dots correspond to QDs grown by metalorganic vapor-phase epitaxy on SiC studied by Kindel et al.¹⁸. All blue data points were extracted from the same sample. Autocorrelation measurements described in the following are performed on the QDs labeled QD_A and QD_B