Abnormal magnetic-field dependence of Hall coefficient in InN epilayers

Abstract

We report on magnetic-field dependences of Hall coefficient and resistivity for InN films grown by plasma-assisted molecular beam epitaxy. The Hall coefficient rises with the magnetic field. This anomalous behavior is discussed in terms of the presence of highly conducting inhomogeneities in the films. According to the magnetic field and temperature dependences of the film resistivity, the inhomogeneities are attributed to metallic indium nanoparticles formed presumably around extended defects within the InN epilayers, at their surface and the InN/GaN interface. Good correlation is observed between the growth conditions of the InN films and their electrical properties recalculated using the model.