Role of impurities and dislocations for the unintentional n-type conductivity in InN
2009 (English)In: PHYSICA B-CONDENSED MATTER, ISSN 0921-4526, Vol. 404, no 22, 4476-4481 p.Article in journal (Refereed) Published
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 10(17) cm(-1) and mid 10(18) 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.
Place, publisher, year, edition, pages
2009. Vol. 404, no 22, 4476-4481 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-52772DOI: 10.1016/j.physb.2009.09.042OAI: oai:DiVA.org:liu-52772DiVA: diva2:285507