# Giant Thermal Switching via Phase Transition in MoTe2

## TL;DR

This paper shows that MoTe2 can switch its thermal conductivity by 270% through a phase transition, offering potential for real-time thermal control in electronics and energy applications.

## Contribution

The study demonstrates a giant thermal switching effect in MoTe2 via a phase transition, enabled by ultrafast and reversible external stimuli.

## Key findings

- MoTe2's thermal conductivity increases by ∼270% during the 2H to 1T′ phase transition.
- Four-phonon processes are responsible for the large thermal conductivity change between phases.
- The phase transition can be triggered by electric fields, light, and THz pulses.

## Abstract

Designing materials with tailor-made thermal properties
is an important
challenge in current condensed matter and nanoscience, particularly
for the implications on efficient thermal management in electronics
and for applications related to energy harvesting such as thermoelectricity.
Even more interesting is the possibility to dynamically access different
heat conduction states, as it potentially leads to the real-time control
of heat flow. Here, we leverage phase-engineering in MoTe2, a 2D van der Waals transition metal dichalcogenide, showing that
the thermal conductivity undergoes a giant increase (∼270%
at room temperature) upon the phase transition between the common
2H and 1T′ polymorphs. Our
first-principles calculations trace back this very large change to
the different effects that four-phonon processes have on the two crystal
phases. Importantly, the 2H ↔ 1T′ phase transition is ultrafast and reversible and can be
triggered by external electric fields, light absorption, and THz pulses.