Strong Schottky barrier reduction at Au-catalyst/GaAs-nanowire interfaces by electric dipole formation and Fermi-level unpinning

Dmitry B. Suyatin, Vishal Jain, Valery A. Nebol'sin, Johanna Trägårdh, Maria E. Messing, Jakob Birkedal Wagner, Olof Persson, Rainer Timm, Anders Mikkelsen, Ivan Maximov, Lars Samuelson, Håkan Pettersson

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Abstract

Nanoscale contacts between metals and semiconductors are critical for further downscaling of electronic and optoelectronic devices. However, realizing nanocontacts poses significant challenges since conventional approaches to achieve ohmic contacts through Schottky barrier suppression are often inadequate. Here we report the realization and characterization of low n-type Schottky barriers (~0.35 eV) formed at epitaxial contacts between Au-In alloy catalytic particles and GaAs-nanowires. In comparison to previous studies, our detailed characterization, employing selective electrical contacts defined by high-precision electron beam lithography, reveals the barrier to occur directly and solely at the abrupt interface between the catalyst and nanowire. We attribute this lowest-to-date-reported Schottky barrier to a reduced density of pinning states (~1017 m-2) and the formation of an electric dipole layer at the epitaxial contacts. The insight into the physical mechanisms behind the observed low-energy Schottky barrier may guide future efforts to engineer abrupt nanoscale electrical contacts with tailored electrical properties.
Original languageEnglish
JournalNature Communications
Volume5
Pages (from-to)3221
Number of pages8
ISSN2041-1723
DOIs
Publication statusPublished - 2014
Externally publishedYes

Cite this

Suyatin, D. B., Jain, V., Nebol'sin, V. A., Trägårdh, J., Messing, M. E., Wagner, J. B., Persson, O., Timm, R., Mikkelsen, A., Maximov, I., Samuelson, L., & Pettersson, H. (2014). Strong Schottky barrier reduction at Au-catalyst/GaAs-nanowire interfaces by electric dipole formation and Fermi-level unpinning. Nature Communications, 5, 3221. https://doi.org/10.1038/ncomms4221