Thorough Representation of Thermal Conductivity of Group VA Puckered Monolayer Structures with a Single Parameter

Tugbey Kocabas, Deniz Cakir, Oguz Gulseren, Feridun Ay, Nihan K. Perkgoz, Cem Sevik

Published 2017-04-24Version 1

Emergence of new two dimensional materials open a new avenue for applications, such as thermoelectricity, based on their astonishing thermal properties. In this respect, lattice thermal transport properties of group \textrm{VA} elements (P, As, Sb, PAs, PSb, AsSb) with black phosphorus like puckered structure are systematically investigated by first principles density functional theory based calculations. In spite of the apparent differences in vibrational properties of these materials, we establish an intriguing correlation between the lattice thermal conductivity, $\kappa$, of all the considered materials. Notably, a single parameter function, $\kappa$(T)=$\alpha\times\kappa_{ref}$(T), well predicts the thermal conductivity of other group \textrm{VA} monolayers using only the thermal conductivity of any reference system ($\kappa_{ref}$(T)), for example phosphorene, as an input, where $\alpha$ is a constant. As expected, phosphorene has the highest thermal conductivity due to its low atomic mass. As a matter of course, anisotropy in relaxation times and phonon group velocities give rise to anisotropic thermal properties, and degree of anisotropy decreases as the mass of constituent atom(s) increases. In addition, the contribution of ZA mode ($<$ 50\%) to the thermal conductivity is markedly small as compared to graphene ($\sim$80\%), and decreases as the average atomic mass in the unit cell increases. We also reveal that thermal conductivity of P, As and Sb monolayers scales as inverse square of atomic mass (i.e. $\kappa$ $\sim$ 1/$m^2$). Moreover, our calculations on alloyed structures clearly resemble that thermoelectric potential of these materials can be improved by suppressing its thermal properties.