Comparative study of thermal properties of group-VA monolayers with buckled and puckered honeycomb structures

Abstract

The thermal properties of monolayers of group-VA elements (P, As, Sb) with graphenelike buckled and black phosphorenelike puckered honeycomb structures are investigated systematically by theoretical calculations based on the phonon Peierls-Boltzmann equation. These structures are found to be thermodynamically stable with no appreciable negative frequencies in the phonon dispersion spectra. Generally, the thermal conductivity decreases as the atomic number increases. Anisotropy of relaxation time and thermal conductivity between armchair and zigzag directions is observed in the puckered structure but absent in the buckled structure. By analyzing the phase space of the thermal resistive three-phonon-scattering process, it is found that the acoustic-optical phonon gaps presented in the buckled structures have significant effects on thermal conductivity, not only affecting relative contribution from each process but also leading to a slight difference in the temperature dependence for buckled phosphorene. Our findings indicate a useful route for tuning the thermal conductivity of structurally similar materials by phonon engineering.