Surface optical modes in GaN nanowires

Prasana Sahoo; S. Dhara; S. Dash; A. K. Tyagi; Baldev Raj; C. R.  Das; P. Chandramohan; M. P. Srinivasan

doi:10.1504/IJNT.2010.034690

Surface optical modes in GaN nanowires

Prasana Sahoo, S. Dhara, S. Dash, A. K. Tyagi, Baldev Raj, C. R. Das, P. Chandramohan, M. P. Srinivasan

Research output: Contribution to journal › Journal article › Research › peer-review

Abstract

We investigate the optical phonons in crystalline GaN nanowires using Raman spectroscopy. Reduced phonon lifetime in the nanostructures is attributed to the increased anisotropy in lattice vibrations. Apart from the group theoretically allowed optical phonons, new phonon modes around 652 cm(-1) and 691 cm(-1) have been observed. In view of its good agreement with values in GaN, the observed phonon mode is assigned as surface optical (SO) phonon. This could be attributed to the surface modulation along the GaN nanowirc diameter and it is quantitatively evaluated with observed surface morphology and the calculated dispersion relation corresponding to SO phonon modes. The modulation in the surface morphology, observed in the present study, is typical of the vapour-liquid-solid growth process. The instability in the surface phonon potential activates the SO phonon modes, which is well explained in this present study.

Original language	English
Journal	International Journal of Networking and Virtual Organisations
Volume	7
Issue number	9-12
Pages (from-to)	823-832
ISSN	1470-9503
DOIs	https://doi.org/10.1504/IJNT.2010.034690
Publication status	Published - 2010
Externally published	Yes

Keywords

Gallium nitride
Raman spectroscopy
Surface modulation
Surface optical mode

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@article{673f079412c04908a511ba46fa487869,

title = "Surface optical modes in GaN nanowires",

abstract = "We investigate the optical phonons in crystalline GaN nanowires using Raman spectroscopy. Reduced phonon lifetime in the nanostructures is attributed to the increased anisotropy in lattice vibrations. Apart from the group theoretically allowed optical phonons, new phonon modes around 652 cm(-1) and 691 cm(-1) have been observed. In view of its good agreement with values in GaN, the observed phonon mode is assigned as surface optical (SO) phonon. This could be attributed to the surface modulation along the GaN nanowirc diameter and it is quantitatively evaluated with observed surface morphology and the calculated dispersion relation corresponding to SO phonon modes. The modulation in the surface morphology, observed in the present study, is typical of the vapour-liquid-solid growth process. The instability in the surface phonon potential activates the SO phonon modes, which is well explained in this present study.",

keywords = "Gallium nitride, Raman spectroscopy, Surface modulation, Surface optical mode",

author = "Prasana Sahoo and S. Dhara and S. Dash and Tyagi, {A. K.} and Baldev Raj and Das, {C. R.} and P. Chandramohan and Srinivasan, {M. P.}",

year = "2010",

doi = "10.1504/IJNT.2010.034690",

language = "English",

volume = "7",

pages = "823--832",

journal = "International Journal of Networking and Virtual Organisations",

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TY - JOUR

T1 - Surface optical modes in GaN nanowires

AU - Sahoo, Prasana

AU - Dhara, S.

AU - Dash, S.

AU - Tyagi, A. K.

AU - Raj, Baldev

AU - Das, C. R.

AU - Chandramohan, P.

AU - Srinivasan, M. P.

PY - 2010

Y1 - 2010

N2 - We investigate the optical phonons in crystalline GaN nanowires using Raman spectroscopy. Reduced phonon lifetime in the nanostructures is attributed to the increased anisotropy in lattice vibrations. Apart from the group theoretically allowed optical phonons, new phonon modes around 652 cm(-1) and 691 cm(-1) have been observed. In view of its good agreement with values in GaN, the observed phonon mode is assigned as surface optical (SO) phonon. This could be attributed to the surface modulation along the GaN nanowirc diameter and it is quantitatively evaluated with observed surface morphology and the calculated dispersion relation corresponding to SO phonon modes. The modulation in the surface morphology, observed in the present study, is typical of the vapour-liquid-solid growth process. The instability in the surface phonon potential activates the SO phonon modes, which is well explained in this present study.

AB - We investigate the optical phonons in crystalline GaN nanowires using Raman spectroscopy. Reduced phonon lifetime in the nanostructures is attributed to the increased anisotropy in lattice vibrations. Apart from the group theoretically allowed optical phonons, new phonon modes around 652 cm(-1) and 691 cm(-1) have been observed. In view of its good agreement with values in GaN, the observed phonon mode is assigned as surface optical (SO) phonon. This could be attributed to the surface modulation along the GaN nanowirc diameter and it is quantitatively evaluated with observed surface morphology and the calculated dispersion relation corresponding to SO phonon modes. The modulation in the surface morphology, observed in the present study, is typical of the vapour-liquid-solid growth process. The instability in the surface phonon potential activates the SO phonon modes, which is well explained in this present study.

KW - Gallium nitride

KW - Raman spectroscopy

KW - Surface modulation

KW - Surface optical mode

U2 - 10.1504/IJNT.2010.034690

DO - 10.1504/IJNT.2010.034690

M3 - Journal article

SN - 1470-9503

VL - 7

SP - 823

EP - 832

JO - International Journal of Networking and Virtual Organisations

JF - International Journal of Networking and Virtual Organisations

IS - 9-12

ER -

Surface optical modes in GaN nanowires

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Keywords

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