Insulator-metal transition of VO2 ultrathin films on silicon: Evidence for an electronic origin by infrared spectroscopy

W. W. Peng, G. Niu, R. Tétot, B. Vilquin, F. Raimondi, J. B. Brubach, E. Amzallag, T. Yanagida, S. Autier-Laurent, P. Lecoeur, P. Roy

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)


We report on the first simultaneous observations of both electronic and structural temperature-induced insulator-to-metal transition (IMT) in VO 2 ultrathin films, made possible by the use of broad range transmission infrared spectroscopy. Thanks to these techniques, the infrared phonon structures, as well as the appearance of the free carrier signature, were resolved for the first time. The temperature-resolved spectra allowed the determination of the temperature hysteresis for both the structural (monoclinic-to-rutile) and electronic (insulator-to-metallic) transitions. The combination of these new observations and DFT simulations for the monoclinic structure allows us to verify the direct transition from monoclinic (M1) to rutile and exclude an intermediate structural monoclinic form (M2). The delay in structural modification compared to the primer electronic transition (325 K compared to 304 K) supports the role of free charges as the transition driving force. The shape of the free charge hysteresis suggests that the primer electronic transition occurs first at 304 K, followed by both its propagation to the heart of the layer and the structural transition when T increases. This study outlines further the potential of VO2 ultrathin films integrated on silicon for optoelectronics and microelectronics.

Original languageEnglish
Article number445402
JournalJournal of Physics Condensed Matter
Issue number44
Publication statusPublished - Nov 6 2013
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics


Dive into the research topics of 'Insulator-metal transition of VO2 ultrathin films on silicon: Evidence for an electronic origin by infrared spectroscopy'. Together they form a unique fingerprint.

Cite this