Towards a better understanding of nano-islands formed during atmospheric pressure MOVPE

We report on transmission electron microscopy (TEM) characterisation of nano-islands formed during atmospheric pressure growth of InGaN on GaN by metal-organic vapour phase epitaxy (MOVPE). Although initial results seemed to indicate that three-dimensional InGaN nano-islands had formed, detailed TEM characterisation revealed that the islands do not have a hexagonal crystal structure, and electron energy loss spectroscopy suggests that the observed structures are metallic indium droplets formed during growth, which may be partially nitrided, rather than the expected strain-induced epitaxial InGaN nano-islands. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)