TY - GEN

T1 - Surface-mediated electrical transport in single GaAs nanowires

AU - Miccoli, Ilio

AU - Edler, Frederik

AU - Pfnür, Herbert

AU - Tegenkamp, Christoph

AU - Prete, Paola

AU - Lovergine, Nico

N1 - Funding information: The financial support through the DFG is gratefully acknowledged. The authors wish also to acknowledge F. Marzo for assistance during growth experiments and S.Korte from “Forschungszentrum Jülich” for useful discussions during the DPG Spring Meeting (Berlin-TU, 15. -20. March 2015).

PY - 2018/8/3

Y1 - 2018/8/3

N2 - 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.

AB - 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.

KW - electrical resistivity

KW - III-V semiconductor nanowire

KW - MOVPE self-assembly

KW - scanning probe microscopy

UR - http://www.scopus.com/inward/record.url?scp=85052230959&partnerID=8YFLogxK

U2 - 10.1109/nanofim.2015.8425344

DO - 10.1109/nanofim.2015.8425344

M3 - Conference contribution

AN - SCOPUS:85052230959

SN - 9781509051519

SP - 136

EP - 140

BT - 2015 1st Workshop on Nanotechnology in Instrumentation and Measurement, NANOFIM 2015

PB - Institute of Electrical and Electronics Engineers Inc.

T2 - 1st Workshop on Nanotechnology in Instrumentation and Measurement, NANOFIM 2015

Y2 - 24 July 2015 through 25 July 2015

ER -