Exciton interaction with acoustic phonons in PbS nanocrystals

The interaction between exciton and acoustic phonons via deformation potential in PbS nanocrystals is calculated in the ${\bf k} \cdot {\bf p}$ model. The size-dependence of the Huang-Rhys factors for the fundamental breathing mode and its overtones as well as for spheroidal vibrations with the total angular momentum $j=2$ are evaluated.