\textbf{Profiling the local carrier concentration and dopant distribution across a semiconductor quantum dot}

ORAL

Abstract

We profile the local carrier concentration, n, across epitaxial InAs/GaAs quantum dots (QDs) consisting of 3D islands on top of a 2D alloy layer. We use scanning thermoelectric microscopy to profile the temperature gradient-induced voltage, which is converted to a profile of the local Seebeck coefficient, S. The S profile is then converted to a conduction band-edge profile and compared with Poisson-Schrodinger band-edge simulations. Our combined computational-experimental approach suggests a reduced carrier concentration in the QD center in comparison to that of the 2D alloy layer. We further use 3D atom probe tomography, which enables 3D imaging with a few Angstrom resolution, to profile the distribution of Si dopants. We discuss the correlation between the Si dopant distribution and the observed carrier concentration profile.

Authors

  • Jenna Walrath

    • Univ of Michigan - Ann Arbor
    • University of Michigan
  • A.S. Chang

    • Univ of Michigan - Ann Arbor
  • Y.H. Lin

    • Univ of Michigan - Ann Arbor
  • S. Huang

    • Univ of Michigan - Ann Arbor
  • R.S. Goldman

    • Univ of Michigan - Ann Arbor