Photoluminescence associated with quantum dots in cubic GaN/InGaN/GaN double heterostructures

We report on investigations of the photoluminescence of cubic GaN/InxGa1-xN GaN double heterostructures with x between 0.09 and 0.33. The room temperature emission of all samples is found all about 2,3 2,4 eV. High resolution X-ray diffraction measurements reveal an In-rich phase with x = 0.56. Luminescence line narrowing, in resonant excitation experiments indicate that the photoluminescence stems from quantum-dot-like structures of the In-rich phase, Postgrowth annealing at temperatures up to 700degreesC demonstrates an obvious stability of the quantum dots. (C) 2002 Elsevier Science B.V. All rights reserved.