Evolution of carrier distribution and defects in InGaAsN/GaAs quantum wells with composition fluctuation

Jenn-Fang Chen*, Ru Shang Hsiao, Pei Chen Hsieh, Yu Chih Chen, Jyh Shyang Wang, Jim Y. Chi

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

Carrier distribution and defect induction in In0.34Ga 0.66As0.98N0.02/GaAs single quantum wells grown by molecular beam epitaxy at low growth rates are investigated by frequency-dependent capacitance-voltage (C-V) and deep-level transient spectroscopy (DLTS). The C-V studies show that lowering the growth rate of the InGaAsN layer splits the carrier accumulation in the well into a central and two side peaks with different frequency dispersions. The DLTS studies show that a continuum of states (0-0.083 eV) and a deep trap at 0.21-0.25 eV are responsible for the central and the side peaks, respectively. A comparison with photoluminescence (PL) spectra shows that these defects are induced by composition fluctuation. Lowering the growth rate degrades composition fluctuation by segregating the material into an InGaAsN phase and an N-depleted phase. Post-growth annealing can remove the deep trap and improve the InGaAsN emission, confirming that the deep trap degrades the InGaAsN phase. The feature of the continuum of states suggests that it may be the structural defects associated with lattice expansion or localized states introduced by composition fluctuation.

Original languageEnglish
Pages (from-to)5662-5666
Number of pages5
JournalJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
Volume45
Issue number7
DOIs
StatePublished - 7 Jul 2006

Keywords

  • Carrier distribution
  • Composition fluctuation
  • Defect traps
  • InGaAsN/GaAs

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