Growth of GaN quantum dots on nonpolar <i>A</i> ‐plane SiC by molecular‐beam epitaxy

Abstract

Abstract We report on A ‐plane GaN quantum dots in AlN, grown on A ‐plane 6H SiC substrates by plasma‐assisted molecular‐beam epitaxy. AFM imaging revealed a strong alignment of the dots along the [1 $ \bar 1 $ 00] direction that we correlated with the anisotropic morphology of the AlN buffer layer. A vertical correlation of these dots was evidenced by high resolution transmission electron microscopy on superlattice samples with an AlN spacer thickness of 5 nm. Time‐resolved spectroscopy performed on both C ‐plane and A ‐plane samples revealed much shorter radiative lifetimes for the A ‐plane dots, indicating a strong reduction of the internal electric field with respect to the one present in their C ‐plane counterparts. (© 2006 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)