Phonon band structures of Si nanowiresPhonon band structures of Si nanowires
Faculty of Sciences. Physics
Condensed Matter Theory
2009New York, 2009
AIP conference proceedings / American Institute of Physics. - New York
1199(2009), p. 323-324
University of Antwerp
We present full ab initio calculations of the phonon band structure of thin Si nanowires oriented along the  direction. Using these phonon dispersion relations we investigate the structural stability of these wires. We found that all studied wires were stable also when doped with either B or P, if the unit cell was taken sufficiently large along the wire axis. The evolution of the phonon dispersion relations and of the sound velocities with respect to the wire diameters is discussed. Softening is observed for acoustic modes and hardening for optical phonon modes with increasing wire diameters.