  Two-dimensional (2D) materials represented by graphene stand out in future
electrical industry and have been widely studied. As a commonly existing factor
in electronic devices, the electric field has been extensively utilized to
modulate the performance. However, how the electric field regulates thermal
transport is rarely studied. Herein, we investigate the modulation of thermal
transport properties by applying the external electric field ranging from 0 to
0.4 VA-1, with bilayer graphene, monolayer silicene, and germanene as study
cases. The monotonic decreasing trend of thermal conductivity of all the three
materials is revealed. The significant effect on the scattering rate is found
to be responsible for the decreased thermal conductivity by electric field.
Further evidences show that the reconstruction of internal electric field and
the generation of induced charges lead to the increased scattering rate from
strong phonon anharmonicity. Thus, the ultra-low thermal conductivity emerges
with external electric field applied. Applying external electric field to
regulate thermal conductivity enlightens the constructive idea for
high-efficient thermal management.
