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Title: The effects of annealing on the structural, optical, and vibrational properties of lattice-matched GaAsSbN/GaAs grown by molecular beam epitaxy

Abstract

The structural, optical, and vibrational properties of a GaAsSbN epilayer lattice matched to GaAs with a band gap of 1 eV have been investigated using a variety of characterization techniques. These layers have potential applications in GaAs based tandem solar cells that utilize the near infrared region of the solar spectrum. The epilayers were grown in an elemental solid source molecular beam epitaxy system with a rf plasma nitrogen source. The Sb and N compositions of the nearly lattice-matched layers are 6.8% and 2.6%, respectively, as determined by high resolution x-ray diffraction and secondary ion mass spectroscopy (SIMS) analysis. The high crystalline quality of the layers is attested by the presence of well resolved Pendellosung fringes on a triple axis (004) x-ray scan and dynamical truncation rods observed on the corresponding (004) reciprocal space map. The effects of in situ annealing in As ambient and ex situ annealing in N ambient on the low temperature photoluminescence (PL) characteristics are discussed. Ex situ (in situ) annealed samples display an 8 K PL peak energy of 1 eV with a full width at half maximum of 18 meV (26 meV). Raman spectral analysis, the temperature dependence of the PL peak energy, andmore » SIMS profiles indicate that outdiffusions of N and As are suppressed in the in situ annealed samples and improvement in Ga-N bonding is observed, leading to higher PL intensities in these samples. In addition, indirect evidence of atomic scale ordering has been observed. The stability of these structures appears to be dependent on the annealing conditions.« less

Authors:
 [1];  [1];  [1];  [1];  [2];  [3];  [3];  [4]
  1. North Carolina A&T State University
  2. Bede Scientific Inc, Englewood, Colorado
  3. Clemson University
  4. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Center for Nanophase Materials Sciences
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
932086
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 102; Journal Issue: 2
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; ANNEALING; BONDING; MASS SPECTROSCOPY; MOLECULAR BEAM EPITAXY; NITROGEN; PHOTOLUMINESCENCE; PLASMA; RESOLUTION; SOLAR CELLS; STABILITY; TEMPERATURE DEPENDENCE; X-RAY DIFFRACTION; GALLIUM ARSENIDES

Citation Formats

Bharatan, S., Iyer, Prof Shanthi, Nunna, K., Collis, W J, Matney, K., Reppert, J., Rao, A. M., and Kent, Paul R. The effects of annealing on the structural, optical, and vibrational properties of lattice-matched GaAsSbN/GaAs grown by molecular beam epitaxy. United States: N. p., 2007. Web. doi:10.1063/1.2753681.
Bharatan, S., Iyer, Prof Shanthi, Nunna, K., Collis, W J, Matney, K., Reppert, J., Rao, A. M., & Kent, Paul R. The effects of annealing on the structural, optical, and vibrational properties of lattice-matched GaAsSbN/GaAs grown by molecular beam epitaxy. United States. doi:10.1063/1.2753681.
Bharatan, S., Iyer, Prof Shanthi, Nunna, K., Collis, W J, Matney, K., Reppert, J., Rao, A. M., and Kent, Paul R. Mon . "The effects of annealing on the structural, optical, and vibrational properties of lattice-matched GaAsSbN/GaAs grown by molecular beam epitaxy". United States. doi:10.1063/1.2753681.
@article{osti_932086,
title = {The effects of annealing on the structural, optical, and vibrational properties of lattice-matched GaAsSbN/GaAs grown by molecular beam epitaxy},
author = {Bharatan, S. and Iyer, Prof Shanthi and Nunna, K. and Collis, W J and Matney, K. and Reppert, J. and Rao, A. M. and Kent, Paul R},
abstractNote = {The structural, optical, and vibrational properties of a GaAsSbN epilayer lattice matched to GaAs with a band gap of 1 eV have been investigated using a variety of characterization techniques. These layers have potential applications in GaAs based tandem solar cells that utilize the near infrared region of the solar spectrum. The epilayers were grown in an elemental solid source molecular beam epitaxy system with a rf plasma nitrogen source. The Sb and N compositions of the nearly lattice-matched layers are 6.8% and 2.6%, respectively, as determined by high resolution x-ray diffraction and secondary ion mass spectroscopy (SIMS) analysis. The high crystalline quality of the layers is attested by the presence of well resolved Pendellosung fringes on a triple axis (004) x-ray scan and dynamical truncation rods observed on the corresponding (004) reciprocal space map. The effects of in situ annealing in As ambient and ex situ annealing in N ambient on the low temperature photoluminescence (PL) characteristics are discussed. Ex situ (in situ) annealed samples display an 8 K PL peak energy of 1 eV with a full width at half maximum of 18 meV (26 meV). Raman spectral analysis, the temperature dependence of the PL peak energy, and SIMS profiles indicate that outdiffusions of N and As are suppressed in the in situ annealed samples and improvement in Ga-N bonding is observed, leading to higher PL intensities in these samples. In addition, indirect evidence of atomic scale ordering has been observed. The stability of these structures appears to be dependent on the annealing conditions.},
doi = {10.1063/1.2753681},
journal = {Journal of Applied Physics},
number = 2,
volume = 102,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
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