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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. 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)
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. https://doi.org/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. 2015. "Profiling the local carrier concentration across a semiconductor quantum dot". United States. https://doi.org/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},
url = {https://www.osti.gov/biblio/22399038}, journal = {Applied Physics Letters},
issn = {0003-6951},
number = 19,
volume = 106,
place = {United States},
year = {Mon May 11 00:00:00 EDT 2015},
month = {Mon May 11 00:00:00 EDT 2015}
}