Thermal Conductivity of Group VA Puckered Monolayer Structures

Lattice thermal transport properties of monolayer structures of the group VA elements
with black phosphorus like puckered structure were systematically investigated by first principles
calculations and an iterative solution of the Boltzmann transport equation for phonons.
Surprisingly, we determined that the thermal conductivity of all the considered materials can be modeled by
a simple formula, κ=c1 + c2/m2. As expected, phosphorene has the highest thermal
conductivity due to its low atomic massand strong bonding between the P atoms. We found that alloying of
the pristine monolayers with P, As, Sb and Bi atoms improves (suppresses) the electronic (thermal)
conductivity. We can achieve a 1.5 Wm⁻¹K⁻¹ at 300 K when we dope phosphorene with Bi.
The contribution of ZA mode (< 50%) to the thermal conductivity is markedly small as compared
to graphene (80%), and decreases as the average atomic mass in the unit cell increases. Moreover,
our calculations on alloyed structures clearly resemble that thermoelectric potential of these mate-
rials can be improved by suppressing its thermal properties. The presence of the ultra-low and
high electrical conductivity makes these class of monolayers
promising candidates for thermoelectric applications.