Electrical Conductivity of InN Nanowires and the Influence of the Native Indium Oxide Formed at Their Surface

• Published in: Nano letters 2009-04, Vol.9 (4), p.1567-1571
• Main Authors: Werner, Florian, Limbach, Friederich, Carsten, Michael, Denker, Christian, Malindretos, Joerg, Rizzi, Angela
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electron and ion emission by liquids and solids; impact phenomena; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Exact sciences and technology; Interfaces, heterostructures, nanostructures; Materials science; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Photoemission and photoelectron spectra; Physics; Quantum wires
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl8036799

The electrical properties of InN nanowires were investigated in four-point probe measurements. The dependence of the conductance on the wire diameter allows distinguishing between “core” bulk (quadratic) and “shell” sheet (linear) contributions. Evidence of the formation of a thin In2O3 layer at the surface of the nanowires is provided by X-ray core level photoemission spectroscopy. The shell conductivity is therefore ascribed to an electron accumulation layer forming at the radial InN/In2O3 interface. Although conductance through the accumulation layer dominates for nanowires below a critical diameter of about 55 nm, the core channel cannot be neglected, even for small nanowires.