Formation of an Organic/Metal Interface State from a Shockley Resonance.
The emergence of an organic/metal interface state is studied for the interface between 3,4,9,10-perylene-tetracarboxylic acid dianhydride (PTCDA) and Ag(100) by means of time- and angle-resolved two-photon photoemission and density functional theory. The interface state is located in the projected band gap of Ag(100), 2.3 eV above the Fermi level, and has an electron lifetime in the 10 fs range. The interface state has no direct counterpart on the clean Ag(100) surface, which only exhibits a broad resonance at ≈1 eV lower energy. Our results thus show that organic overlayers are able to shift such a resonance substantially and even qualitatively change its character to a distinct electronic state at the interface.
†Fachbereich Physik, ‡Fachbereich Chemie and Zentrum für Materialwissenschaften, Philipps-Universität Marburg, D-35032 Marburg, Germany.
Martin C E
MC
Galbraith
†Fachbereich Physik, ‡Fachbereich Chemie and Zentrum für Materialwissenschaften, Philipps-Universität Marburg, D-35032 Marburg, Germany.
Manuel
M
Marks
†Fachbereich Physik, ‡Fachbereich Chemie and Zentrum für Materialwissenschaften, Philipps-Universität Marburg, D-35032 Marburg, Germany.
Ralf
R
Tonner
†Fachbereich Physik, ‡Fachbereich Chemie and Zentrum für Materialwissenschaften, Philipps-Universität Marburg, D-35032 Marburg, Germany.
Ulrich
U
Höfer
PTCDA; charge transfer; density functional theory; electron dynamics; organic thin films; time-resolved 2-photon photoemission (2PPE)