Surface-mediated electrical transport in single GaAs nanowires

authored by: Ilio Miccoli, Frederik Edler, Herbert Pfnür, Christoph Tegenkamp, Paola Prete, Nico Lovergine
Abstract: III-V semiconductor compound based nanowires (NWs) are expected to impact the fields of nano-electronic, nano-photonic, and photovoltaic devices. Self-assembly of crystal-phase controlled and high optical quality III-V NWs has been demonstrated. However, important physical and technological issues, such as carrier transport properties and reproducible incorporation of high dopant concentrations in NW materials, remain to be addressed for enabling robust nano-devices fabrication. In this work, we show the use of a multi-probe scanning tunneling microscope for the rapid electrical characterization of free-standing GaAs NWs, without any need for post-growth sample processing and contact fabrication. In particular, 2-probe I-V measurements were performed along the axis of a single 60-nm diameter unpassivated GaAs NW, and its resistance profile determined, obtaining high (in the range of GΩ) resistance values. Due to its reduced radial dimension, the NW is expected to be completely depleted. Analysis of the NW resistance profile reveals instead, that carrier transport is mediated by the NW surface states. Finally, by using the substrate as a reference electrode and placing the other three STM-tips along the NWs, we demonstrate a 4-point probe geometry that can be used for the electrical characterization of highly doped NWs.
Organisation(s): Surfaces Science Section
Institute of Solid State Physics
External Organisation(s): University of Salento
National Research Council Italy (CNR)
Type: Conference contribution
Pages: 136-140
No. of pages: 5
Publication date: 03.08.2018
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Electronic, Optical and Magnetic Materials, Instrumentation
Sustainable Development Goals: SDG 7 - Affordable and Clean Energy
Electronic version(s): https://doi.org/10.1109/nanofim.2015.8425344 (Access: Closed)