University of Surrey

Test tubes in the lab Research in the ATI Dance Research

The electronic band structure of GaBiAs/GaAs layers: Influence of strain and band anti-crossing

Batool, Z, Hild, K, Hosea, TJC, Lu, X, Tiedje, T and Sweeney, SJ (2012) The electronic band structure of GaBiAs/GaAs layers: Influence of strain and band anti-crossing JOURNAL OF APPLIED PHYSICS, 111 (11). ? - ?. ISSN 0021-8979

[img]
Preview
PDF
JApplPhys_111_113108.pdf
Available under License : See the attached licence file.

Download (1336Kb)
[img]
Preview
PDF (licence)
SRI_deposit_agreement.pdf

Download (32Kb)

Abstract

The GaBi As bismide III-V semiconductor system remains a relatively underexplored alloy particularly with regards to its detailed electronic band structure. Of particular importance to understanding the physics of this system is how the bandgap energy E and spin-orbit splitting energy Δ vary relative to one another as a function of Bi content, since in this alloy it becomes possible for Δ to exceed E for higher Bi fractions, which occurrence would have important implications for minimising non-radiative Auger recombination losses in such structures. However, this situation had not so far been realised in this system. Here, we study a set of epitaxial layers of GaBi As (2.3 x 10.4), of thickness 30-40 nm, grown compressively strained onto GaAs (100) substrates. Using room temperature photomodulated reflectance, we observe a reduction in E , together with an increase in Δ , with increasing Bi content. In these strained samples, it is found that the transition energy between the conduction and heavy-hole valence band edges is equal with that between the heavy-hole and spin-orbit split-off valence band edges at ∼9.0 ± 0.2 Bi. Furthermore, we observe that the strained valence band heavy-hole/light-hole splitting increases with Bi fraction at a rate of ∼15 (±1) meV/Bi, from which we are able to deduce the shear deformation potential. By application of an iterative strain theory, we decouple the strain effects from our experimental measurements and deduce E and Δ of free standing GaBiAs; we find that Δ indeed does come into resonance with E at ∼10.5 ± 0.2 Bi. We also conclude that the conduction/valence band alignment of dilute-Bi GaBiAs on GaAs is most likely to be type-I.

Item Type: Article
Additional Information:

Copyright 2012 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.

The following article appeared in Journal of Applied Physics 111 (11) 113108 and may be found at Z. Batool et al., JAP 111, 113108 (2012)

Uncontrolled Keywords: Science & Technology, Physical Sciences, Physics, Applied, Physics, MOLECULAR-BEAM EPITAXY, MODULATION SPECTROSCOPY, GAAS1-XBIX, PHOTOREFLECTANCE, SEMICONDUCTORS, TEMPERATURE, DEPENDENCE, GAP
Related URLs:
Divisions: Faculty of Engineering and Physical Sciences > Electronic Engineering > Advanced Technology Institute > Photonics
Depositing User: Symplectic Elements
Date Deposited: 11 Oct 2012 09:57
Last Modified: 23 Sep 2013 19:43
URI: http://epubs.surrey.ac.uk/id/eprint/728515

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year


Information about this web site

© The University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
+44 (0)1483 300800