Photothermal effects control ultrafast charge transport in titanium carbide MXenes

Zheng, W.; Ramsden, H.; Ippolito, S.; Hemert, M van.; Zhang, D.; Zhang, T.; ... ; Wang, H.I. (2026)

Article / Letter to editor

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 Ti3C2Tx. 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.

• All authors: Zheng, W.; Ramsden, H.; Ippolito, S.; Hemert, M van.; Zhang, D.; Zhang, T.; Li, D.; Wen, G.; Geuchies, J.J.; Yu, M.; Feng, X.; Gogotsi, Y.; Tielrooij, K.J.; Wang, H.I.
• Date: 2026-01-29
• Journal: Nature Communications
• Volume: 17
• Issue: 1
• DOI: doi:10.1038/s41467-026-68831-4
• Link: https://www.nature.com/articles/s41467-026-68831-4