Electron–acoustic phonon interaction and mobility in stressed rectangular silicon nanowires

We investigate the effects of pre-stress and surface tension on the electron–acoustic phonon scattering rate and the mobility of rectangular silicon nanowires.With the elastic theory and the interaction Hamiltonian for the deformation potential,which considers both the surface energy and the acoustoelastic effects,the phonon dispersion relation for a stressed nanowire under spatial confinement is derived.The subsequent analysis indicates that both surface tension and pre-stress can dramatically change the electron–acoustic phonon interaction.Under a negative(positive)surface tension and a tensile(compressive)pre-stress,the electron mobility is reduced(enhanced)due to the decrease(increase)of the phonon energy as well as the deformation-potential scattering rate.This study suggests an alternative approach based on the strain engineering to tune the speed and the drive current of low-dimensional electronic devices.