Charge separation at the molecular monolayer surface: Observation and control of the dynamics

Masahiro Shibuta, Naoyuki Hirata, Ryo Matsui, Toyoaki Eguchi, Atsushi Nakajima

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21 Citations (Scopus)


Charge separation dynamics relevant to an electron transfer have been revealed by time- and angle-resolved two-photon photoemission spectroscopy for an n-alkanethiolate self-assembled monolayer (SAM) on a Au(111) surface fabricated by a chemical-wet process. The electron was photoexcited into an image potential state located at 3.7 eV above the Fermi level (E F), and it survived well for more than 100 ps on dodecanethiolate (C12)-SAM. The degree of electron separation is precisely controlled by selecting the length of the alkyl chain (C10-C18). We have also evaluated molecular conductivity at the specific electron energy of E F + 3.7 eV. The tunneling decay parameter, β, was fitted by β 90 K = 0.097 Å -1 and β RT = 0.13 Å -1. These values were one order smaller than that at around E F by conventional contact probe methods.

Original languageEnglish
Pages (from-to)981-985
Number of pages5
JournalJournal of Physical Chemistry Letters
Issue number8
Publication statusPublished - 2012 Apr 19


ASJC Scopus subject areas

  • Materials Science(all)
  • Physical and Theoretical Chemistry

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