Carrier transfer and recombination dynamics of a long-lived and visible range emission from multi-stacked GaN/AlGaN quantum dots

We have investigated the optical properties of multi-stacked GaN/AlGaN self-assembled quantum dots (QDs) grown by molecular beam epitaxy. The QDs that emit visible light have a broad spectral range without incorporation of indium alloy because of the quantum-confined Stark effect. We found differences in the structural and optical properties between the layers of multi-stacked QDs. The carriers are more effectively transferred from the AlGaN barrier to the low energy side of the GaN QD emission than to the high energy side. We also observed long-lived carrier recombination dynamics for the visible range emission from QDs. (C) 2010 American Institute of Physics. [doi:10.1063/1.3473777]