Localized tip enhanced Raman spectroscopic study of impurity incorporated single GaN nanowire in the sub-diffraction limit
- Surface and Nanoscience Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)
The localized effect of impurities in single GaN nanowires in the sub-diffraction limit is reported using the study of lattice vibrational modes in the evanescent field of Au nanoparticle assisted tip enhanced Raman spectroscopy (TERS). GaN nanowires with the O impurity and the Mg dopants were grown by the chemical vapor deposition technique in the catalyst assisted vapor-liquid-solid process. Symmetry allowed Raman modes of wurtzite GaN are observed for undoped and doped nanowires. Unusually very strong intensity of the non-zone center zone boundary mode is observed for the TERS studies of both the undoped and the Mg doped GaN single nanowires. Surface optical mode of A{sub 1} symmetry is also observed for both the undoped and the Mg doped GaN samples. A strong coupling of longitudinal optical (LO) phonons with free electrons, however, is reported only in the O rich single nanowires with the asymmetric A{sub 1}(LO) mode. Study of the local vibration mode shows the presence of Mg as dopant in the single GaN nanowires.
- OSTI ID:
- 22482144
- Journal Information:
- Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 12 Vol. 107; ISSN APPLAB; ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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