Plasmonic MXenes are of particular interest, because of their unique electron and phonon structures and multiple surface plasmon effects, which are different from traditional plasmonic materials. However, to date, how electronic energy damp to lattice vibrations (phonons) in MXenes has not been unraveled. Here, we employed ultrafast broadband impulsive vibrational spectroscopy to identify the energy damping channels in MXenes (Ti3C2Tx and Mo2CTx). Distinctive from the well-known damping pathways, our results demonstrate a different energy damping channel, in which the Ti3C2Tx plasmonic electron energy transfers to coherent phonons by nonthermal electron mediation after Landau damping, without involving electron-electron scattering. Moreover, electrons are observed to strongly couple with A1g mode (~60 fs, 85–100%) and weakly couple with Eg mode (1–2 ps, 0–15%). Our results provide new insight into the electron-phonon interaction in MXenes, which allows the design of materials enabling efficient manipulation of electron transport and energy conversion.
The
thermal management of MXene (Ti3C2T
x
) plays a crucial role in its performance
during various emerging applications. However, it is unclear how the
inevitable oxidation structure of Ti3C2T
x
influences the thermal dissipation, which
might hinder its long-term performance and even create thermal damage.
Here we show the thermal migration of a Ti3C2T
x
flake with surface oxidation in film
and water by combining ultrafast pump–probe technique with
molecular dynamics (MD) simulations. The results demonstrate that
the oxidation at the surface could facilitate interfacial thermal
migration with shorter interfacial distances but would block the lateral
thermal transfer. Besides, our results also identified that the slight
oxidation could not obviously change the thermal decay of Ti3C2T
x
nanosheets in water due
to similar hydrogen bonds between water and interface. The research
not only provides fundamental understanding of the thermal dissipation
of MXene but also benefits for designing the thermal dissipation system
to the MXene device.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.