Conduction band structure in wurtzite GaAs nanowires: A resonant Raman scattering study

We report on a room temperature Raman resonance at 1.56 eV in GaAs wurtzite nanowires together with the emergence of a strong forbidden longitudinal optical phonon line. We attribute this resonance, absent in zinc blende wires with similar diameters, to an additional excitonic transition due to conduction band folding in agreement with recent theoretical predictions. (C) 2012 American Institute of Physics. [doi:10.1063/1.3684837]