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Profiling the local carrier concentration across a semiconductor quantum dot

Authors :
J. C. Walrath
Rachel Goldman
Yen-Hsiang Lin
Simon Huang
Source :
Applied Physics Letters. 106:192101
Publication Year :
2015
Publisher :
AIP Publishing, 2015.

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.

Details

ISSN :
10773118 and 00036951
Volume :
106
Database :
OpenAIRE
Journal :
Applied Physics Letters
Accession number :
edsair.doi...........2d73c16ba1241f35248c20cc1d0b363b
Full Text :
https://doi.org/10.1063/1.4919919