6533b7d7fe1ef96bd1268488
RESEARCH PRODUCT
Anticrossing of axial and planar surface-related phonon modes in Raman spectra of self-assembled GaN nanowires
R. PechouJunkang WangAna CrosAnne PonchetF. DemangeotBruno Daudinsubject
Materials sciencePhononNanowirePhysics::Optics02 engineering and technologyDielectric01 natural sciencessymbols.namesakeCondensed Matter::Materials Science0103 physical sciencesSpectroscopyWurtzite crystal structure010302 applied physics[PHYS]Physics [physics]Condensed matter physicsbusiness.industryFilling factor021001 nanoscience & nanotechnologyCondensed Matter PhysicsCondensed Matter::Mesoscopic Systems and Quantum Hall EffectElectronic Optical and Magnetic MaterialssymbolsOptoelectronics0210 nano-technologybusinessRaman spectroscopyRaman scatteringdescription
cited By 17; International audience; GaN columnar nanostructures usually called nanowires have been investigated by micro-Raman spectroscopy. In addition to conventional Raman scattering by confined optical phonons of a wurtzite structure (i.e., E 2h and QLO modes), an unusual two peaks band centered near 700 cm -1 is observed and analyzed as a function of several experimental parameters (polarization, filling factor, incidence angle). The surface character of these two modes is experimentally confirmed by their high sensitivity to the dielectric constant of the as-grown nanowires surrounding medium. Calculations describing the nanowires' environment by means of an effective dielectric function are in good agreement with this two peaks structure and suggest that these two peaks result from the anticrossing of axial and planar surface-related phonons, which should be observed in all anisotropic polar semiconductors.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-04-16 |