Photoluminescence study of GaAsSbN bulk epilayers on GaAs substrates

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?????/??????????????Photoluminescence study of
GaAsSbN bulk epilayers on GaAs substrates

• Student Tsung-Yi Chen
• Adviser Hao-Hsiung Lin

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Introductionproperties of dilute N IIINV alloys

• High bandgap bowing
• Carrier localization at low temperature
• Sensitivity to thermal annealing

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Introductionadvantage of GaAsSbN

• Conduction- and valence-band offsets can be
  independently tuned by adjusting the N and Sb
  composition, respectively.
• GaNAsSb material can be designed to be
  lattice-matched to GaAs, allowing us to grow
  thick layers that can be used in photodetectors
  or solar cells.
• GaNAsSb requires less N that the relatively large
  amount necessary for a GaInNAs QW emits at 1.55µm.

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Conclusion

• The temperature dependence of energy gap of
  GaAsSbN is similar to that of GaAsN.
• The energy reduction induced by N incorporation
  in GaAsSbN is independent of Sb composition.
• The activation energy of the low temperature part
  is related to the compositional fluctuation
  induced by N.
• The activation energy of the low temperature part
  is related to deep level defects, which also
  cause the emission of the deep PL band, and the
  emission intensity will decreases with the
  increase of Sb or N.