Raman scattering study of InAs/GaInSb strained layer superlattices

Journal Article · Fri Nov 15 00:00:00 EST 1991 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.350174· OSTI ID:5049856

Sela, I; Campbell, I H; Laurich, B K; Smith, D L ^[1]; Samoska, L A; Bolognesi, C R; Gossard, A C; Kroemer, H ^[2]

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1. Los Alamos National Laboratory, Los Alamos, New Mexico (USA)
2. Electrical and Computer Engineering, and Engineering Materials Departments, University of California at Santa Barbara, Santa Barbara, California (USA)

We present a Raman scattering study of the InAs/GaInSb superlattice. This new superlattice is promising as a long wavelength infrared detector material. The samples were grown by molecular beam epitaxy and their structural parameters were determined by Rutherford backscattering and x-ray diffraction. Samples were grown on (001) GaAs substrates with GaSb buffers, and directly on (001) GaSb substrates. Cross-sectional transmission electron micrographs show that for the samples grown on GaAs substrates, a high density of dislocations was generated at the GaAs-GaSb interface, and many of these dislocations thread through the superlattice. The samples grown directly on GaSb had a much lower dislocation density. The Raman spectra of the InAs/GaInSb superlattice shows a single peak, which is a superposition of scattering from the LO phonons in InAs and in GaInSb. For unstrained InAs and GaInSb, the LO phonon energies are sufficiently separated that they would be well resolved in Raman scattering. However, the strain introduced into these materials by the pseudomorphic boundary conditions moves the two phonons closer together energetically so that only one peak is seen in the Raman spectrum of the superlattice. A high energy Raman scattering tail is seen in some of the samples. This tail is from Ga-As local modes. Such modes may be due to As incorporation in the GaInSb, Ga incorporation in the InAs or phase mixing at the interfaces.

• OSTI ID: 5049856
• Journal Information: Journal of Applied Physics; (United States), Vol. 70:10; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
GALLIUM ANTIMONIDES
RAMAN SPECTROSCOPY
INDIUM ANTIMONIDES
INDIUM ARSENIDES
DISLOCATIONS
MOLECULAR BEAM EPITAXY
PHONONS
STRAINS
SUPERLATTICES
ANTIMONIDES
ANTIMONY COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
EPITAXY
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
LASER SPECTROSCOPY
LINE DEFECTS
PNICTIDES
QUASI PARTICLES
SPECTROSCOPY
360603* - Materials- Properties
360601 - Other Materials- Preparation & Manufacture