Non-polar GaN quantum dots integrated into high quality cubic AlN microdisks

Abstract

We report on lasing of non-polar GaN quantum dots which are integrated into novel cubic AlN microdisks. Optical spectroscopy of freestanding microdisks at low temperature (∼10 K) revealed distinct whispering gallery modes with quality factors up to Q ∼3000 in the high energy range around ∼4 eV of microdisks with a diameter of 4 μm. Furthermore, we obtained S-shaped curves of the integral mode intensity, accompanied by a significant linewidth narrowing in power dependent micro-photoluminescence experiments. The spontaneous emission coupling factors were determined to β = 0.26 and β = 0.58 with respect to the radial order of the resonator modes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.