Determination of the Mg occupation site in MOCVD-and MBE-grown Mg-doped InN using X-ray absorption fine-structure measurements

We analyzed the atomic structure around Mg atoms in MOCVD- and MBE-grown Mg-doped InN using Mg K-edge X-ray absorption fine-structure (XAFS) measurements. Our experimental data closely fit to the simulated data in which Mg atoms occupy the substitutional sites of In atoms. From this result, we conclude that Mg atoms essentially occupy not N atoms sites but In atoms sites, meaning that Mg atoms can act as acceptors in InN. We believe that observations of p-type conductivity are prevented by problems such as carrier compensation and electron accumulation at the surface. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)