Growth and assessment of InGaN quantum dots in a microcavity: A blue single photon source

Using a modified droplet epitaxy approach in metal-organic vapour phase epitaxy (MOVPE), we have grown InGaN quantum dots (QDs) on top of a 20-period AlN/GaN distributed Bragg reflector (DBR). The QDs were located at the centre of a ca. 182 nm GaN layer. To complete the cavity a three-period SiOx/SiNx DBR was deposited onto the GaN surface. Despite the evolution of roughness during the growth of the AlN/GaN DBR, due to cracking of the AlN layers, a cavity mode was observed, with a quality-factor of ∼50. Enhanced single QD emission was observed in micro-photoluminescence studies of the sample, and photon-correlation spectra provided evidence for single photon emission.