skip to main content

SciTech ConnectSciTech Connect

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

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
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 19; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
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