skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Profiling the local carrier concentration across a semiconductor quantum dot

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 measure a profile of 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. The relative roles of free carrier trapping and/or dopant expulsion are discussed.

Authors:
;  [1];  [2];  [1];  [3]
  1. Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)
  2. Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)
  3. (United States)
Publication Date:
OSTI Identifier:
22399038
Resource Type:
Journal Article
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 106; Journal Issue: 19; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0003-6951
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; CHARGE CARRIERS; COMPARATIVE EVALUATIONS; CONCENTRATION RATIO; ELECTRIC POTENTIAL; ELECTRONIC STRUCTURE; EPITAXY; GALLIUM ARSENIDES; INDIUM ARSENIDES; LAYERS; MICROSCOPY; QUANTUM DOTS; SEEBECK EFFECT; SEMICONDUCTOR MATERIALS; TEMPERATURE GRADIENTS; TRAPPING

Citation Formats

Walrath, J. C., Lin, Yen-Hsiang, Huang, S., Goldman, R. S., E-mail: rsgold@umich.edu, and Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109. Profiling the local carrier concentration across a semiconductor quantum dot. United States: N. p., 2015. Web. doi:10.1063/1.4919919.
Walrath, J. C., Lin, Yen-Hsiang, Huang, S., Goldman, R. S., E-mail: rsgold@umich.edu, & Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109. Profiling the local carrier concentration across a semiconductor quantum dot. United States. doi:10.1063/1.4919919.
Walrath, J. C., Lin, Yen-Hsiang, Huang, S., Goldman, R. S., E-mail: rsgold@umich.edu, and Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109. Mon . "Profiling the local carrier concentration across a semiconductor quantum dot". United States. doi:10.1063/1.4919919.
@article{osti_22399038,
title = {Profiling the local carrier concentration across a semiconductor quantum dot},
author = {Walrath, J. C. and Lin, Yen-Hsiang and Huang, S. and Goldman, R. S., E-mail: rsgold@umich.edu and Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109},
abstractNote = {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 measure a profile of 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. The relative roles of free carrier trapping and/or dopant expulsion are discussed.},
doi = {10.1063/1.4919919},
journal = {Applied Physics Letters},
issn = {0003-6951},
number = 19,
volume = 106,
place = {United States},
year = {2015},
month = {5}
}