Effects of AlSb interfaces on InAs/InAsSb type-II infrared superlattice material properties

Elizabeth H. Steenbergen, Zhi Yuan Lin, Said Elhamri, William C. Mitchel, Yong-Hang Zhang, Ron Kaspi

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

3 Scopus citations


Significant attention has recently been given to photoluminescence (PL) spectra and lifetime measurements on InAs/InAsSb superlattices, as high quality optical material with long carrier lifetimes are required for infrared detectors. The standard sample structure for PL measurements includes energy barriers to block photo-generated carriers from being lost through non-radiative recombination at interfaces between the superlattice and the surface or between the superlattice and the buffer/substrate. However, defect, surface, and/or interface states in AlSb, a commonly used barrier material, are known to contribute carriers to InAs quantum wells. Due to the similarity of the AlSb interface with the InAs/InAsSb superlattice, the effects of the barriers on the electrical and optical properties of the superlattice were investigated. Structures with AlSb barriers at the top and bottom of the superlattice, with no AlSb barriers, and with an AlSb barrier only at the top of the superlattice structure were studied. Hall Effect measurements revealed little change in the sheet carrier concentration at 10 K due to the barriers, but significant increases in low temperature mobility and a two-dimensional-like mobility temperature dependence were observed when barriers were present. Further high magnetic field measurements are necessary, however, to understand the transport properties of these samples due to the likelihood that multiple carriers are present. The photoluminescence (PL) spectra were almost identical regardless of the barriers, except for a 15% increase in intensity with the AlSb barrier between the buffer layer and the superlattice. The surface AlSb barrier had little effect on the intensity. The barriers are therefore recommended for PL measurements to increase the signal intensity; however, they complicate the analysis of single-field Hall Effect measurements.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
StatePublished - 2015
Event41st Conference on Infrared Technology and Applications - Baltimore, United States
Duration: Apr 20 2015Apr 23 2015


Other41st Conference on Infrared Technology and Applications
Country/TerritoryUnited States


  • detector
  • Hall Effect
  • infrared
  • photoluminescence
  • superlattice

ASJC Scopus subject areas

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


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