Photothermal effects control ultrafast charge transport in titanium carbide MXenes.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41611693.
- Also identified by DOI 10.1038/s41467-026-68831-4 and PMC identifier 12858860.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Titanium carbide MXene (Ti₃C₂Tₓ) is an emerging metallic material with promise for (opto)electronics and thermal management. Yet how photoexcitation-particularly via photogenerated thermal energy-modifies its charge carrier dynamics remains poorly understood. By combining time-resolved terahertz spectroscopy and transient reflectance measurements, we reveal a long-lived, photo-induced suppression of conductivity, which we attribute to efficient lattice heating and slow heat dissipation in Ti₃C₂T<sub>x</sub>. A systematic variation of pump photon energy reveals that this 'negative' photoconductivity can equivalently be induced by lattice temperature increases, indicating a thermal origin. Repetition-rate-dependent transient reflectance measurements further show residual heat persisting over 100 ns, substantially longer than in conventional metals. Our work presents a unified understanding of photothermal effects in Ti₃C₂Tₓ and their influence on non-equilibrium charge transport, underscoring its potential for photothermal electronics and light-to-thermal energy storage applications.