MBE growth and photoreflectance study of GaAsN alloy films grown on GaAs (0 0 1)

A. Nishikawa, R. Katayama, K. Onabe, Y. Shiraki

Research output: Contribution to journalConference article

20 Citations (Scopus)

Abstract

The growth condition of GaAsN alloy films has been optimized for higher N contents, and the bandgap energy of the films and its temperature dependence have been investigated by photoreflectance spectroscopy. The GaAsN (N = 0-4.5%) alloy films were grown on GaAs (0 0 1) substrates by molecular beam epitaxy equipped with a radio frequency plasma nitrogen source. The As4 flux was varied for the optimization of the growth. The films with a fairly flat surface and high crystal quality were obtained when the As4 flux was close to the V/III ratio of 1. The bandgap energy of GaAsN with the N content of 4.5% was measured as low as 0.93 eV (1.33 μm). In the low (< 1%) N content region, the bowing parameter is estimated to be 22eV. However, the deviation of the experimental data from the fitting curve becomes large as the N content increases due to the composition-dependent nature of the bowing. The temperature dependence of the bandgap energy becomes significantly weak with increasing N content. This suggests that the density of states around the band edge of GaAsN is modified from that of GaAs due to the localized states possibly originated from N clusters.

Original languageEnglish
Pages (from-to)427-431
Number of pages5
JournalJournal of Crystal Growth
Volume251
Issue number1-4
DOIs
Publication statusPublished - 2003 Apr 1
EventProceedings of the Molecular Beam Epitaxy 2002 - San Francisco, CA, United States
Duration: 2002 Sep 152002 Sep 20

Keywords

  • A1. Bandgap
  • A1. Photreflectance
  • A3. Molecular beam epitaxy
  • B1. GaAsN

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Inorganic Chemistry
  • Materials Chemistry

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