posted on 2024-02-01, 14:40authored byXihao Chen, Guangzhao Wang, Bingke Li, Ning Wang
Two-dimensional graphenelike material, hexagonal boron
phosphide
(h-BP), is a promising candidate for electronic and optoelectronic
devices because of its suitable band gap and high carrier mobility.
Especially from the ultrahigh lattice thermal conductivity (κl), it exhibits great potential to solve the challenges of
future thermal management applications. Here, the excellent lattice
thermal transport properties of the h-BP monolayer are systematically
analyzed at the atomic level based on the first-principles method.
The results show that the ultrahigh κl value of the
h-BP monolayer is attributed to its high phonon group velocity and
long phonon lifetime and the strong phonon hydrodynamic effect. We
further explore the influence of the tensile strain on the thermal
transport properties of the h-BP monolayer. As the strain increases
from 0 to 8%, the κl value shows a trend of first
increasing and then decreasing due to the coeffect of strain-driven
changes for phonon harmonicity and anharmonicity. Under a strain of
6%, the κl value of the h-BP monolayer is as high
as 795 W/mK at 300 K, which is about 2.22 times larger than that of
357 W/mK without strain. Such a significant increase in the κl value is mainly due to the increased phonon group velocity
and decreased Grüneisen parameter caused by strain. This work
is helpful to understand the critical role of tensile strain in lattice
thermal transport of two-dimensional graphenelike materials. It is
conducive to promoting the thermal management application of the h-BP
monolayer.