Lattice dynamics of black phosphorus

Abstract

A force-constant model calculation of the phonon dispersion and frequency distribution function of black phosphorus, which is a narrow-gap and layer-like semiconductor, is presented. In calculation, we assume the valence force model for intralayer atomic interactions and the axially symmetric force model for interlayer ones. The calculated results explain experiments on optical phonons, specific heat and second-order Raman spectrum satisfactorily and sound velocities semi-quantitatively. Large discrepancy between theory and experiment on the linear compressibilities exists.