This title appears in the Scientific Report :
2009
Please use the identifier:
http://hdl.handle.net/2128/17192 in citations.
Please use the identifier: http://dx.doi.org/10.1063/1.3148862 in citations.
Raman scattering of phonon-plasmon coupled modes in self-assemled GaN nanowires
Raman scattering of phonon-plasmon coupled modes in self-assemled GaN nanowires
We report the determination of free-electron concentration and mobility of free-standing GaN nanowires (NWs) by line shape analysis of the coupled longitudinal optical phonon-plasmon Raman modes (L+). The E-2(high) phonon mode at 566.9 cm(-1) with a sharp linewidth of 2.8 cm(-1) indicates strain fre...
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Personal Name(s): | Jeganathan, K. |
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Debnath, R. K. / Meijers, R. / Stoica, T. / Calarco, R. / Grützmacher, D. / Lüth, H. | |
Contributing Institute: |
Halbleiter-Nanoelektronik; IBN-1 JARA-FIT; JARA-FIT |
Published in: | Journal of applied physics, 105 (2009) S. 123707 |
Imprint: |
Melville, NY
American Institute of Physics
2009
|
Physical Description: |
123707 |
DOI: |
10.1063/1.3148862 |
Document Type: |
Journal Article |
Research Program: |
Grundlagen für zukünftige Informationstechnologien |
Series Title: |
Journal of Applied Physics
105 |
Subject (ZB): | |
Link: |
Get full text OpenAccess OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://dx.doi.org/10.1063/1.3148862 in citations.
We report the determination of free-electron concentration and mobility of free-standing GaN nanowires (NWs) by line shape analysis of the coupled longitudinal optical phonon-plasmon Raman modes (L+). The E-2(high) phonon mode at 566.9 cm(-1) with a sharp linewidth of 2.8 cm(-1) indicates strain free NWs with high crystalline perfection. The lattice temperature of the NWs was varied between 313 and 472 K by varying the excitation laser beam power. For unintentionally doped samples at room temperature, an average electron concentration and mobility of strain free NWs were found to be similar to 2 x 10(17) cm(-3) and 460 cm(2)/V s, respectively. We have shown that the electron concentration does not change significantly over a temperature range between 313 and 472 K. The electron mobility decreases at high temperatures, in agreement with literature data for compact layers. For Si-doped NWs, the L+ phonon peak is strongly upshifted indicating a higher free-carrier concentration of about 1 x 10(18) cm(-3). Asymmetric broadening observed at the lower frequency side of the L+ phonon peak might be ascribed to the enhancement in surface optical modes due to the high surface-to-volume ratio of NWs. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3148862] |