Atomistic Modeling of the Phonon Dispersion and Lattice Properties of Free-Standing <100> Si Nanowires

Abhijeet Paul, NCN, Purdue University
Mathieu Luisier, NCN, Purdue University
Gerhard Klimeck, NCN, Purdue University

Date of this Version



Proceedings of the International Workshop for Computational Electronics, Pisa, Italy, October 2010

arXiv:1010.0367v1 [cond-mat.mes-hall] 2 Oct 2010


Phonon dispersions in ⟨100⟩ silicon nanowires (SiNW) are modeled using a Modified Valence Force Field (MVFF) method based on atomistic force constants. The model replicates the bulk Si phonon dispersion very well. In SiNWs, apart from four acoustic like branches, a lot of flat branches appear indicating strong phonon confinement in these nanowires and strongly affecting their lattice properties. The sound velocity (Vsnd) and the lattice thermal conductance (κl) decrease as the wire cross-section size is reduced whereas the specific heat (Cv) increases due to increased phonon confinement and surface-to-volume ratio (SVR).


Nanoscience and Nanotechnology