Research Article

Nano Research

, Volume 3, Issue 10, pp 706-713

Open Access This content is freely available online to anyone, anywhere at any time.

Contactless monitoring of the diameter-dependent conductivity of GaAs nanowires

  • Fauzia JabeenAffiliated withSincrotrone Trieste S. C. P. A., Elettra LaboratoryLaboratorio TASC IOM-CNR
  • , Silvia RubiniAffiliated withLaboratorio TASC IOM-CNR Email author 
  • , Faustino MartelliAffiliated withLaboratorio TASC IOM-CNR
  • , Alfonso FranciosiAffiliated withSincrotrone Trieste S. C. P. A., Elettra LaboratoryLaboratorio TASC IOM-CNR
  • , Andrei KolmakovAffiliated withDepartment of Physics, Southern Illinois University Carbondale
  • , Luca GregorattiAffiliated withSincrotrone Trieste S. C. P. A., Elettra Laboratory
  • , Matteo AmatiAffiliated withSincrotrone Trieste S. C. P. A., Elettra Laboratory
  • , Alexei BarinovAffiliated withSincrotrone Trieste S. C. P. A., Elettra Laboratory
  • , Andrea GoldoniAffiliated withSincrotrone Trieste S. C. P. A., Elettra Laboratory

Abstract

Contactless monitoring with photoelectron microspectroscopy of the surface potential along individual nanostructures, created by the X-ray nanoprobe, opens exciting possibilities to examine quantitatively size- and surface-chemistry-effects on the electrical transport of semiconductor nanowires (NWs). Implementing this novel approach-which combines surface chemical microanalysis with conductivity measurements-we explored the dependence of the electrical properties of undoped GaAs NWs on the NW width, temperature and surface chemistry. By following the evolution of the Ga 3d and As 3d core level spectra, we measured the position-dependent surface potential along the GaAs NWs as a function of NW diameter, decreasing from 120 to ?20 nm, and correlated the observed decrease of the conductivity with the monotonic reduction in the NW diameter from 120 to ~20 nm. Exposure of the GaAs NWs to oxygen ambient leads to a decrease in their conductivity by up to a factor of 10, attributed to the significant decrease in the carrier density associated with the formation of an oxide shell. http://static-content.springer.com/image/art%3A10.1007%2Fs12274-010-0034-4/MediaObjects/12274_2010_34_Fig1_HTML.jpg

Keywords

Semiconductor nanowires charge transport surface oxidation photoelectron X-ray microscopy charging GaAs