# Distinct Correlation between the Vibrational and Thermal Transport Properties of Group \textrm{VA} Monolayer Crystals

## TL;DR

This study systematically investigates the vibrational and thermal transport properties of group VA monolayer crystals, revealing correlations and potential for tuning thermal conductivity through alloying for thermoelectric applications.

## Contribution

It provides the first comprehensive first-principles analysis of thermal transport in group VA monolayers, highlighting correlations between vibrational and thermal properties and the effects of alloying.

## Key findings

- Phosphorene has the highest thermal conductivity among studied materials.
- Anisotropic thermal conductivity observed in all materials.
- Alloying can significantly reduce or enhance thermal conductivity.

## Abstract

The investigation of thermal transport properties of novel two dimensional materials is crucially important in order to assess their potential to be used in future technological applications, such as thermoelectric power generation. In this respect, lattice thermal transport properties of monolayer structures of the group \textrm{VA} elements (P, As, Sb, Bi, PAs, PSb, PBi, AsSb, AsBi, SbBi, P$_{3}$As$_{1}$, P$_{3}$Sb$_{1}$, P$_{1}$As$_{3}$, As$_{3}$Sb$_{1}$) with black phosphorus like puckered structure were systematically investigated by first principles calculations and an iterative solution of the Phonon Boltzmann transport equation. Phosphorene was found to have the highest lattice thermal conductivity, $\kappa$, due to its low average atomic mass and strong interatomic bonding character. As a matter of course, anisotropic $\kappa$ were obtained for all the considered materials, owing to anisotropy in phonon group velocities and scattering rates (relaxation times) calculated for these structures. However, the determined linear correlation between the anisotropy in $\kappa$ of P, As, and Sb is significant. The results corresponding to the studied compound structures clearly point out that thermal (electronic) conductivity of pristine monolayers might be suppressed (improved) by alloying them with the same group elements. For instance, the room temperature $\kappa$ of PBi along armchair direction was predicted as low as 1.5 Wm$^{-1}$K$^{-1}$, whereas that of P was predicted to be 21 Wm$^{-1}$K$^{-1}$. In spite of the apparent differences in structural and vibrational properties, we peculiarly revealed an intriguing correlation between the $\kappa$ of all the considered materials as $\kappa$=c$_{1}$ + c$_{2}$/$m^{2}$, in particular along zigzag direction.