Universality in electron–modulated-acoustic-phonon interactions in a free-standing semiconductor nanowire

Modulated acoustic phonons and their interactions with electrons in a free-standing cylindrical semiconductor nanowire are investigated theoretically. It is shown that the form factor is a key quantity in discussing the impact of acoustic phonons on electron transport. The form factor calculated using modulated acoustic phonons is identical to that calculated using bulk phonons for a large phonon wave vector along the wire, whereas it is larger for a small phonon wave vector. This increase directly leads to an increase in the electron scattering rate and a reduction in mobility. In addition, the form factor increase has a universality independent of the wire material and radius.