Assessing the nature of the distribution of localised states in bulk GaAsBi
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
A comprehensive assessment of the nature of the distribution of sub band-gap energy states in bulk GaAsBi is presented using
power and temperature dependent photoluminescence spectroscopy. The observation of a characteristic red-blue-red shift in
the peak luminescence energy indicates the presence of short-range alloy disorder in the material. A decrease in the carrier
localisation energy demonstrates the strong excitation power dependence of localised state behaviour and is attributed to the
filling of energy states furthest from the valence band edge. Analysis of the photoluminescence lineshape at low temperature
presents strong evidence for a Gaussian distribution of localised states that extends from the valence band edge. Furthermore,
a rate model is employed to understand the non-uniform thermal quenching of the photoluminescence and indicates the
presence of two Gaussian-like distributions making up the density of localised states. These components are attributed to the
presence of microscopic fluctuations in Bi content, due to short-range alloy disorder across the GaAsBi layer, and the formation
of Bi related point defects, resulting from low temperature growth.
power and temperature dependent photoluminescence spectroscopy. The observation of a characteristic red-blue-red shift in
the peak luminescence energy indicates the presence of short-range alloy disorder in the material. A decrease in the carrier
localisation energy demonstrates the strong excitation power dependence of localised state behaviour and is attributed to the
filling of energy states furthest from the valence band edge. Analysis of the photoluminescence lineshape at low temperature
presents strong evidence for a Gaussian distribution of localised states that extends from the valence band edge. Furthermore,
a rate model is employed to understand the non-uniform thermal quenching of the photoluminescence and indicates the
presence of two Gaussian-like distributions making up the density of localised states. These components are attributed to the
presence of microscopic fluctuations in Bi content, due to short-range alloy disorder across the GaAsBi layer, and the formation
of Bi related point defects, resulting from low temperature growth.
Date Issued
2018-04-24
Date Acceptance
2018-03-27
Citation
Scientific Reports, 2018, 8
ISSN
2045-2322
Publisher
Nature Publishing Group
Journal / Book Title
Scientific Reports
Volume
8
Copyright Statement
© The Author(s) 2018. This article is licensed under a Creative Commons Attribution 4.0 International
License, which permits use, sharing, adaptation, distribution and reproduction in any medium or
format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Cre-
ative Commons license, and indicate if changes were made. The images or other third party material in this
article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the
material. If material is not included in the article’s Creative Commons license and your intended use is not per-
mitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the
copyright holder. To view a copy of this license, visit
http://creativecommons.org/licenses/by/4.0/
License, which permits use, sharing, adaptation, distribution and reproduction in any medium or
format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Cre-
ative Commons license, and indicate if changes were made. The images or other third party material in this
article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the
material. If material is not included in the article’s Creative Commons license and your intended use is not per-
mitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the
copyright holder. To view a copy of this license, visit
http://creativecommons.org/licenses/by/4.0/
Subjects
Science & Technology
Multidisciplinary Sciences
Science & Technology - Other Topics
MOLECULAR-BEAM EPITAXY
SEMICONDUCTOR ALLOY GAAS1-XBIX
BAND-GAP
GROWTH
PHOTOLUMINESCENCE
HETEROSTRUCTURES
DEPENDENCE
LATTICES
Publication Status
Published
Article Number
ARTN 6457