Berkeley Lab
researchers have experimentally confirmed strong in-plane anisotropy
in thermal
conductivity along the zigzag (ZZ) and armchair (AC) directions of
single-crystal
black phosphorous nanoribbons.
(October 18, 2015) Berkeley
Lab Researchers Discover Unique Thermal Properties in 2D Black Phosphorous
Nanoribbons
A new experimental revelation about black phosphorus
nanoribbons should facilitate the future application of this highly promising
material to electronic, optoelectronic and thermoelectric devices. A team of
researchers at the U.S. Department of Energy (DOE)’s Lawrence Berkeley National
Laboratory (Berkeley Lab) has experimentally confirmed strong in-plane
anisotropy in thermal conductivity, up to a factor of two, along the zigzag and
armchair directions of single-crystal black phosphorous nanoribbons.
“Imagine the lattice of black phosphorous as a
two-dimensional network of balls connected with springs, in which the network
is softer along one direction of the plane than another,” says Junqiao Wu, a
physicist who holds joint appointments with Berkeley Lab’s Materials Sciences
Division and the University of California (UC) Berkeley’s Department of
Materials Science and Engineering. “Our study shows that in a similar manner
heat flow in the black phosphorous nanoribbons can be very different along
different directions in the plane. This thermal conductivity anisotropy has
been predicted recently for 2D black phosphorous crystals by theorists but
never before observed.”