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 at about 2.3–View the MathML source. 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 700°C demonstrates an obvious stability of the quantum dots.