Metal/Phthalocyanine Hybrid Interface States on Ag(111).
A phthalocyanine/Ag(111) interface state is observed for the first time using time- and angle-resolved two-photon photoemission. For monolayer films of metal-free (H2Pc) and iron phthalocyanine (FePc) on Ag(111), the state exists 0.23 ± 0.03 and 0.31 ± 0.03 eV above the Fermi level, respectively. Angle-resolved spectra show the state to be highly dispersive with an effective mass of 0.50 ± 0.15 me for H2Pc and 0.67 ± 0.14 me for FePc. Density functional theory calculations on the H2Pc/Ag(111) surface allow us to characterize this state as being a hybrid state resulting from the interaction between the unoccupied molecular states of the phthalocyanine ligand and the Shockley surface state present on the bare Ag(111) surface. This work, when taken together with the extensive literature on the 3,4,9,10-perylene tetracarboxylic dianhydride/Ag interface state, provides compelling evidence that the hybridization of metal surface states with molecular electronic states is a general phenomenon.
Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, United States.|Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Benjamin W
BW
Caplins
Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, United States.|Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
David E
DE
Suich
Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, United States.|Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Alex J
AJ
Shearer
Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, United States.|Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Charles B
CB
Harris
charge transfer; density functional theory; electron dynamics; organic thin films; phthalocyanine; two-photon photoemission (TPPE)