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Title: Raman scattering by the E{sub 2h} and A{sub 1}(LO) phonons of In{sub x}Ga{sub 1-x}N epilayers (0.25 < x < 0.75) grown by molecular beam epitaxy

Abstract

We use Raman scattering to investigate the composition behavior of the E{sub 2h} and A{sub 1}(LO) phonons of In{sub x}Ga{sub 1-x}N and to evaluate the role of lateral compositional fluctuations and in-depth strain/composition gradients on the frequency of the A{sub 1}(LO) bands. For this purpose, we have performed visible and ultraviolet Raman measurements on a set of high-quality epilayers grown by molecular beam epitaxy with In contents over a wide composition range (0.25 < x < 0.75). While the as-measured A{sub 1}(LO) frequency values strongly deviate from the linear dispersion predicted by the modified random-element isodisplacement (MREI) model, we show that the strain-corrected A{sub 1}(LO) frequencies are qualitatively in good agreement with the expected linear dependence. In contrast, we find that the strain-corrected E{sub 2h} frequencies exhibit a bowing in relation to the linear behavior predicted by the MREI model. Such bowing should be taken into account to evaluate the composition or the strain state of InGaN material from the E{sub 2h} peak frequencies. We show that in-depth strain/composition gradients and selective resonance excitation effects have a strong impact on the frequency of the A{sub 1}(LO) mode, making very difficult the use of this mode to evaluate the strain statemore » or the composition of InGaN material.« less

Authors:
; ; ;  [1];  [2];  [3]; ;  [4];  [5]; ;  [6]
  1. Institut Jaume Almera, Consell Superior d'Investigacions Cientifiques (CSIC), Lluis Sole i Sabaris s.n, 08028 Barcelona, Catalonia (Spain)
  2. Institute of Physics, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland)
  3. Faculty of Microsystem Electronics and Photonics, Wroclaw University of Technology, Janiszewskiego 11/17, 50-372 Wroclaw (Poland)
  4. Departamento de Fisica de la Materia Condensada, Cristalografia, y Mineralogia, Universidad de Valladolid, 47011 Valladolid (Spain)
  5. Nottingham Nanotechnology and Nanoscience Centre, University of Nottingham, Nottingham NG7 2RD (United Kingdom)
  6. Department of Physics, University of Houston, 4800 Calhoun, Houston, Texas 77004 (United States)
Publication Date:
OSTI Identifier:
22036829
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 111; Journal Issue: 6; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; CONCENTRATION RATIO; CRYSTAL GROWTH; EXCITATION; FLUCTUATIONS; GALLIUM NITRIDES; INDIUM NITRIDES; LAYERS; MOLECULAR BEAM EPITAXY; PHONONS; RAMAN SPECTRA; RANDOMNESS; RESONANCE; SEMICONDUCTOR MATERIALS; STRAINS; ULTRAVIOLET SPECTRA

Citation Formats

Oliva, R., Ibanez, J., Cusco, R., Artus, L., Kudrawiec, R., Serafinczuk, J., Martinez, O., Jimenez, J., Henini, M., Boney, C., and Bensaoula, A.. Raman scattering by the E{sub 2h} and A{sub 1}(LO) phonons of In{sub x}Ga{sub 1-x}N epilayers (0.25 < x < 0.75) grown by molecular beam epitaxy. United States: N. p., 2012. Web. doi:10.1063/1.3693579.
Oliva, R., Ibanez, J., Cusco, R., Artus, L., Kudrawiec, R., Serafinczuk, J., Martinez, O., Jimenez, J., Henini, M., Boney, C., & Bensaoula, A.. Raman scattering by the E{sub 2h} and A{sub 1}(LO) phonons of In{sub x}Ga{sub 1-x}N epilayers (0.25 < x < 0.75) grown by molecular beam epitaxy. United States. doi:10.1063/1.3693579.
Oliva, R., Ibanez, J., Cusco, R., Artus, L., Kudrawiec, R., Serafinczuk, J., Martinez, O., Jimenez, J., Henini, M., Boney, C., and Bensaoula, A.. Thu . "Raman scattering by the E{sub 2h} and A{sub 1}(LO) phonons of In{sub x}Ga{sub 1-x}N epilayers (0.25 < x < 0.75) grown by molecular beam epitaxy". United States. doi:10.1063/1.3693579.
@article{osti_22036829,
title = {Raman scattering by the E{sub 2h} and A{sub 1}(LO) phonons of In{sub x}Ga{sub 1-x}N epilayers (0.25 < x < 0.75) grown by molecular beam epitaxy},
author = {Oliva, R. and Ibanez, J. and Cusco, R. and Artus, L. and Kudrawiec, R. and Serafinczuk, J. and Martinez, O. and Jimenez, J. and Henini, M. and Boney, C. and Bensaoula, A.},
abstractNote = {We use Raman scattering to investigate the composition behavior of the E{sub 2h} and A{sub 1}(LO) phonons of In{sub x}Ga{sub 1-x}N and to evaluate the role of lateral compositional fluctuations and in-depth strain/composition gradients on the frequency of the A{sub 1}(LO) bands. For this purpose, we have performed visible and ultraviolet Raman measurements on a set of high-quality epilayers grown by molecular beam epitaxy with In contents over a wide composition range (0.25 < x < 0.75). While the as-measured A{sub 1}(LO) frequency values strongly deviate from the linear dispersion predicted by the modified random-element isodisplacement (MREI) model, we show that the strain-corrected A{sub 1}(LO) frequencies are qualitatively in good agreement with the expected linear dependence. In contrast, we find that the strain-corrected E{sub 2h} frequencies exhibit a bowing in relation to the linear behavior predicted by the MREI model. Such bowing should be taken into account to evaluate the composition or the strain state of InGaN material from the E{sub 2h} peak frequencies. We show that in-depth strain/composition gradients and selective resonance excitation effects have a strong impact on the frequency of the A{sub 1}(LO) mode, making very difficult the use of this mode to evaluate the strain state or the composition of InGaN material.},
doi = {10.1063/1.3693579},
journal = {Journal of Applied Physics},
number = 6,
volume = 111,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2012},
month = {Thu Mar 15 00:00:00 EDT 2012}
}