UV Photoluminescence from Size-Controlled GaN Quantum Dots Grown by MOCVD

We have successfully grown GaN self-assembled quantum dots (QDs) with high quality by low-pressure metalorganic chemical vapor deposition (MOCVD). We have found that the size of the GaN QDs can be well controlled by changing the growth temperature under low V/III ratio. Controlling the size of QDs leads to a variation of the photoluminescence (PL) peak in the range between 300 and 350 nm, while maintaining high quantum efficiency. The observed PL spectrum having two peaks from both wetting layer and the QDs gives clear evidence that the QDs formed with the Stanski–Krastnanow growth mode. The growth technique of the GaN QDs developed here is promising for application to highly efficient UV light emitters.