Electron transfer dynamics at metal/organic interface

Research Summary

Electron transfer at interfaces is a ubiquitous process in many chemical disciplines including photocatalysis, fuel cells, and organic transistors. The mechanisms involved are of considerable interest not only from a fundamental point of view but also for designing improved functionality. We have developed a femtosecond time-resolved two-photon photoemission spectroscopic technique to investigate electron transfer dynamics under well-defined conditions. We applied this technique to the Alq3/Cu(111) interface and revealed the photoinduced charge transfer dynamics at the interface. Ultrafast charge transfer and the subsequent relaxation dynamics were observed via the transient spectral change of the photoemitted electrons.

fig. 3-1
An energy diagram of Alq3-covered Cu(111) studied by time-resolved two-photon photoemission spectroscopy.

fig. 3-2
A typical trace of time-resolved two-photon photoemission spectra from Alq3-covered Cu(111). The peak of the Alq3 affinity level (circles) shows an energy shift with the time delay.


  • "The electronic structure and femtosecond electron transfer dynamics at noble metal/tris-(8-hydroxyquinoline) aluminum interfaces",
    D. Ino, K. Watanabe, N. Takagi and Y. Matsumoto, Phys. Rev. B, 71, 115427 (2005).
  • "Electron Transfer Dynamics from Organic Adsorbate to a Semiconductor Surface: Zinc-Phthalocyanine on TiO2(110)",
    D. Ino, K. Watanabe, N. Takagi, and Y. Matsumoto, J. Phys. Chem. B, 109, 18018-18024 (2005).

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