A theoretical study of electron mobility reduction due to acoustic phonon modulation in a free-standing semiconductor nanowire

Impacts of modulated acoustic phonons on electron transport in a free-standing cylindrical semiconductor nanowire are theoretically studied. We formulate the electron scattering rate and mobility limited by the intra-valley acoustic phonon scattering mechanism, using bulk and modulated acoustic phonons in a [001]-directed Si nanowire. The scattering rate calculated using modulated acoustic phonons is larger than that with bulk phonons, and therefore the mobility is smaller when modulated acoustic phonons are incorporated. These results are attributed to an increase of the form factor due to acoustic phonon modulation. The form factor increase has a universality independent of wire material and radius.