Quantum dot emission from selectively-grown InGaN/GaN micropyramid arrays

InxGa1-xN quantum dots have been fabricated by the selective growth of GaN micropyramid arrays topped with InGaN/GaN quantum wells. The spatially-, spectrally-, and time-resolved emission properties of these structures were measured using cathodoluminescence hyper-spectral imaging and low-temperature microphotoluminescence spectroscopy. The presence of InGaN quantum dots was confirmed directly by the observation of sharp peaks in the emission spectrum at the pyramid apices. These luminescence peaks exhibit decay lifetimes of approximately 0.5 ns, with linewidths down to 650 mu eV (limited by the spectrometer resolution)