Study of the valence band offsets between InAs and InAs 1-xSb x alloys

Elizabeth H. Steenbergen, Oray O. Cellek, Dmitri Lubyshev, Yueming Qiu, Joel M. Fastenau, Amy W K Liu, Yong-Hang Zhang

Research output: Chapter in Book/Report/Conference proceedingConference contribution

12 Scopus citations

Abstract

InAs/InAs 1-xSb x strain-balanced superlattices (SLs) on GaSb are a viable alternative to the well-studied InAs/Ga 1-xIn xSb SLs for mid- and long-wavelength infrared (MWIR and LWIR) laser and photodetector applications, but the InAs/InAs 1-xSb x SLs are not as thoroughly investigated. Therefore, the valence band offset between InAs and InAs/InAs 1-xSb x, a critical parameter necessary to predict the SL bandgap, must be further examined to produce InAs/InAs 1-xSb x SLs for devices operational at MWIR and LWIR wavelengths. The effective bandgap energies of InAs/InAs 1-xSb x SLs with x = 0.28 - 0.40 are designed using a three-band envelope function approximation model. Multiple 0.5 μm-thick SL samples are grown by molecular beam epitaxy on GaSb substrates. Structural characterization using x-ray diffraction and atomic force microscopy reveals excellent crystalline properties with SL zero-order peak full-width-half-maximums between 30 and 40 arcsec and 20 x 20 μm2 area root-mean-square roughnesses of 1.6 - 2.7 A. Photoluminescence (PL) spectra of these samples cover 5 to 8 μm, and the band offset between InAs and InAs/InAs 1-xSb x is obtained by fitting the PL peaks to the calculated values. The bowing in the valence band is found to depend on the initial InAs/InSb valence band offset and changes linearly with x as C Ev-bowing= 1.58x - 0.62 eV when an InAs/InAs 1-xSb x bandgap bowing parameter of 0.67 eV is assumed. A fractional valence band offset, Q v = ΔE v/ΔE g, of 1.75 ± 0.03 is determined and is practically constant in the composition range studied.

Original languageEnglish (US)
Title of host publicationQuantum Sensing and Nanophotonic Devices IX
DOIs
StatePublished - Feb 20 2012
EventQuantum Sensing and Nanophotonic Devices IX - San Francisco, CA, United States
Duration: Jan 22 2012Jan 26 2012

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume8268
ISSN (Print)0277-786X

Other

OtherQuantum Sensing and Nanophotonic Devices IX
CountryUnited States
CitySan Francisco, CA
Period1/22/121/26/12

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Keywords

  • band alignment
  • band offsets
  • infrared
  • superlattice

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Cite this

Steenbergen, E. H., Cellek, O. O., Lubyshev, D., Qiu, Y., Fastenau, J. M., Liu, A. W. K., & Zhang, Y-H. (2012). Study of the valence band offsets between InAs and InAs 1-xSb x alloys. In Quantum Sensing and Nanophotonic Devices IX [82680K] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 8268). https://doi.org/10.1117/12.907101