Role of impurities and dislocations for the unintentional n-type conductivity in InN

V. Darakchieva, N. P. Barradas, M. Y. Xie, K. Lorenz, E. Alves, M. Schubert, P. O.Å Persson, F. Giuliani, F. Munnik, C. L. Hsiao, L. W. Tu, W. J. Schaff

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

We present a study on the role of dislocations and impurities for the unintentional n-type conductivity in high-quality InN grown by molecular beam epitaxy. The dislocation densities and H profiles in films with free electron concentrations in the low 1017 cm- 3 and mid 1018 cm- 3 range are measured, and analyzed in a comparative manner. It is shown that dislocations alone could not account for the free electron behavior in the InN films. On the other hand, large concentrations of H sufficient to explain, but exceeding substantially, the observed free electron densities are found. Furthermore, enhanced concentrations of H are revealed at the film surfaces, resembling the free electron behavior with surface electron accumulation. The low-conductive film was found to contain C and it is suggested that C passivates the H donors or acts as an acceptor, producing compensated material in this case. Therefore, it is concluded that the unintentional impurities play an important role for the unintentional n-type conductivity in InN. We suggest a scenario of H incorporation in InN that may reconcile the previously reported observations for the different role of impurities and dislocations for the unintentional n-type conductivity in InN.

Original languageEnglish (US)
Pages (from-to)4476-4481
Number of pages6
JournalPhysica B: Condensed Matter
Volume404
Issue number22
DOIs
StatePublished - Dec 1 2009

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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