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Title: Bandgap measurements and the peculiar splitting of E{sub 2}{sup H} phonon modes of In{sub x}Al{sub 1-x}N nanowires grown by plasma assisted molecular beam epitaxy

Abstract

The dislocation free In{sub x}Al{sub 1-x}N nanowires (NWs) are grown on Si(111) by nitrogen plasma assisted molecular beam epitaxy in the temperature regime of 490 °C–610 °C yielding In composition ranges over 0.50 ≤ x ≤ 0.17. We study the optical properties of these NWs by spectroscopic ellipsometry (SE), photoluminescence, and Raman spectroscopies since they possesses minimal strain with reduced defects comparative to the planar films. The optical bandgap measurements of In{sub x}Al{sub 1-x}N NWs are demonstrated by SE where the absorption edges of the NW samples are evaluated irrespective of substrate transparency. A systematic Stoke shift of 0.04–0.27 eV with increasing x was observed when comparing the micro-photoluminescence spectra with the Tauc plot derived from SE. The micro-Raman spectra in the NWs with x = 0.5 showed two-mode behavior for A{sub 1}(LO) phonons and single mode behavior for E{sub 2}{sup H} phonons. As for x = 0.17, i.e., high Al content, we observed a peculiar E{sub 2}{sup H} phonon mode splitting. Further, we observe composition dependent frequency shifts. The 77 to 600 K micro-Raman spectroscopy measurements show that both AlN- and InN-like modes of A{sub 1}(LO) and E{sub 2}{sup H} phonons in In{sub x}Al{sub 1-x}N NWs are redshifted with increasing temperature, similar tomore » that of the binary III group nitride semiconductors. These studies of the optical properties of the technologically important In{sub x}Al{sub 1-x}N nanowires will path the way towards lasers and light-emitting diodes in the wavelength of the ultra-violet and visible range.« less

Authors:
; ; ; ; ;  [1]; ;  [2]; ; ;  [3]
  1. Photonics Laboratory, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia)
  2. Adavanced nanofabrication Imaging and characterization, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia)
  3. National Center for Nanotechnology, King Abdulaziz City for Science and Technology (KACST), Riyadh 11442-6086 (Saudi Arabia)
Publication Date:
OSTI Identifier:
22597790
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 120; Journal Issue: 4; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION; ALUMINIUM NITRIDES; DEFECTS; DISLOCATIONS; ELLIPSOMETRY; FILMS; INDIUM NITRIDES; LIGHT EMITTING DIODES; MOLECULAR BEAM EPITAXY; MOLECULAR BEAMS; NANOWIRES; OPACITY; PHONONS; PHOTOLUMINESCENCE; PLASMA; RAMAN SPECTRA; RAMAN SPECTROSCOPY; RED SHIFT; SEMICONDUCTOR MATERIALS

Citation Formats

Tangi, Malleswararao, Mishra, Pawan, Janjua, Bilal, Ng, Tien Khee, Prabaswara, Aditya, Ooi, Boon S., E-mail: boon.ooi@kaust.edu.sa, Anjum, Dalaver H., Yang, Yang, Albadri, Abdulrahman M., Alyamani, Ahmed Y., and El-Desouki, Munir M. Bandgap measurements and the peculiar splitting of E{sub 2}{sup H} phonon modes of In{sub x}Al{sub 1-x}N nanowires grown by plasma assisted molecular beam epitaxy. United States: N. p., 2016. Web. doi:10.1063/1.4959260.
Tangi, Malleswararao, Mishra, Pawan, Janjua, Bilal, Ng, Tien Khee, Prabaswara, Aditya, Ooi, Boon S., E-mail: boon.ooi@kaust.edu.sa, Anjum, Dalaver H., Yang, Yang, Albadri, Abdulrahman M., Alyamani, Ahmed Y., & El-Desouki, Munir M. Bandgap measurements and the peculiar splitting of E{sub 2}{sup H} phonon modes of In{sub x}Al{sub 1-x}N nanowires grown by plasma assisted molecular beam epitaxy. United States. doi:10.1063/1.4959260.
Tangi, Malleswararao, Mishra, Pawan, Janjua, Bilal, Ng, Tien Khee, Prabaswara, Aditya, Ooi, Boon S., E-mail: boon.ooi@kaust.edu.sa, Anjum, Dalaver H., Yang, Yang, Albadri, Abdulrahman M., Alyamani, Ahmed Y., and El-Desouki, Munir M. Thu . "Bandgap measurements and the peculiar splitting of E{sub 2}{sup H} phonon modes of In{sub x}Al{sub 1-x}N nanowires grown by plasma assisted molecular beam epitaxy". United States. doi:10.1063/1.4959260.
@article{osti_22597790,
title = {Bandgap measurements and the peculiar splitting of E{sub 2}{sup H} phonon modes of In{sub x}Al{sub 1-x}N nanowires grown by plasma assisted molecular beam epitaxy},
author = {Tangi, Malleswararao and Mishra, Pawan and Janjua, Bilal and Ng, Tien Khee and Prabaswara, Aditya and Ooi, Boon S., E-mail: boon.ooi@kaust.edu.sa and Anjum, Dalaver H. and Yang, Yang and Albadri, Abdulrahman M. and Alyamani, Ahmed Y. and El-Desouki, Munir M.},
abstractNote = {The dislocation free In{sub x}Al{sub 1-x}N nanowires (NWs) are grown on Si(111) by nitrogen plasma assisted molecular beam epitaxy in the temperature regime of 490 °C–610 °C yielding In composition ranges over 0.50 ≤ x ≤ 0.17. We study the optical properties of these NWs by spectroscopic ellipsometry (SE), photoluminescence, and Raman spectroscopies since they possesses minimal strain with reduced defects comparative to the planar films. The optical bandgap measurements of In{sub x}Al{sub 1-x}N NWs are demonstrated by SE where the absorption edges of the NW samples are evaluated irrespective of substrate transparency. A systematic Stoke shift of 0.04–0.27 eV with increasing x was observed when comparing the micro-photoluminescence spectra with the Tauc plot derived from SE. The micro-Raman spectra in the NWs with x = 0.5 showed two-mode behavior for A{sub 1}(LO) phonons and single mode behavior for E{sub 2}{sup H} phonons. As for x = 0.17, i.e., high Al content, we observed a peculiar E{sub 2}{sup H} phonon mode splitting. Further, we observe composition dependent frequency shifts. The 77 to 600 K micro-Raman spectroscopy measurements show that both AlN- and InN-like modes of A{sub 1}(LO) and E{sub 2}{sup H} phonons in In{sub x}Al{sub 1-x}N NWs are redshifted with increasing temperature, similar to that of the binary III group nitride semiconductors. These studies of the optical properties of the technologically important In{sub x}Al{sub 1-x}N nanowires will path the way towards lasers and light-emitting diodes in the wavelength of the ultra-violet and visible range.},
doi = {10.1063/1.4959260},
journal = {Journal of Applied Physics},
number = 4,
volume = 120,
place = {United States},
year = {Thu Jul 28 00:00:00 EDT 2016},
month = {Thu Jul 28 00:00:00 EDT 2016}
}