Potassium-intercalated H2Pc films: alkali-induced electronic and geometrical modifications.

X-ray spectroscopy studies of potassium intercalated metal-free phthalocyanine multilayers adsorbed on Al(110) have been undertaken. Photoelectron spectroscopy measurements show the presence of several charge states of the molecules upon K intercalation, due to a charge transfer from the alkali. In addition, the comparison of valence band photoemission spectra with the density functional theory calculations of the density of states of the H(2)Pc(-) anion indicates a filling of the formerly lowest unoccupied molecular orbital by charge transfer from the alkali. This is further confirmed by x-ray absorption spectroscopy (XAS) studies, which show a decreased density of unoccupied states. XAS measurements in different experimental geometries reveal that the molecules in the pristine film are standing upright on the surface or are only slightly tilted away from the surface normal but upon K intercalation, the molecular orientation is changed in that the tilt angle of the molecules increases.

[1]  S. Riad,et al.  Dark and photoelectric conversion properties of p-MgPc/n-Si (Organic/Inorganic) heterojunction cells. , 2000 .

[2]  S. Nannarone,et al.  Electronic Properties and Orbital-Filling Mechanism in Rb-Intercalated Copper Phthalocyanine , 2008 .

[3]  M. Knupfer,et al.  Electronic properties of potassium-doped CuPc , 2005 .

[4]  M. Knupfer,et al.  Full characterization of the interface between the organic semiconductor copper phthalocyanine and gold , 2002 .

[5]  S. Oscarsson,et al.  Activity boost of a biomimetic oxidation catalyst by immobilization onto a gold surface , 2006 .

[6]  M. Knupfer,et al.  Electronic properties of potassium-doped FePc , 2010 .

[7]  A. Morpurgo,et al.  Potassium Phthalocyanine, KPc: one-dimensional molecular stacks bridged by K+ ions. , 2006, Inorganic chemistry.

[8]  L. Lozzi,et al.  Thin and ultra-thin films of nickel phthalocyanine grown on highly oriented pyrolitic graphite: an XPS, UHV-AFM and air tapping-mode AFM study , 1997 .

[9]  A. Becke.  Density-functional thermochemistry. III. The role of exact exchange , 1993 .

[10]  M. Knupfer,et al.  Potassium induced phase transition of FePc thin films. , 2008, The Journal of chemical physics.

[11]  Yongli Gao,et al.  Cs doping and energy level shift in CuPc , 2003 .

[12]  J. Rubensson,et al.  Beamline I511 at MAX II, capabilities and performance , 1999 .

[13]  N. Papageorgiou,et al.  High resolution synchrotron radiation PES study of PbPc deposited on Pt(111) , 2000 .

[14]  Yi Luo,et al.  The electronic structure of iron phthalocyanine probed by photoelectron and x-ray absorption spectroscopies and density functional theory calculations. , 2006, The Journal of chemical physics.

[15]  M. Casu,et al.  Growth mode and molecular orientation of phthalocyanine molecules on metal single crystal substrates: A NEXAFS and XPS study , 2006 .

[16]  H. Siegbahn,et al.  Electronic structure of a vapor-deposited metal-free phthalocyanine thin film. , 2005, The Journal of chemical physics.

[17]  Mark A. Ratner,et al.  6-31G * basis set for atoms K through Zn , 1998 .

[18]  Y. Niwa,et al.  X‐ray photoelectron spectroscopy of tetraphenylporphin and phthalocyanine , 1974 .

[19]  M. Göthelid,et al.  Self-ordering of metal-free phthalocyanine on InAs(100) and InSb(100) , 2006 .

[20]  Strong correlations in electron doped phthalocyanine conductors near half filling. , 2004, Physical review letters.

[21]  M. Knupfer,et al.  Electronic structure of the organic semiconductor copper phthalocyanine and K-CuPc studied using photoemission spectroscopy , 2002 .

[22]  M. Knupfer,et al.  Growth of zinc phthalocyanine onto ZnS film investigated by synchrotron radiation-excited X-ray photoelectron and near-edge absorption spectroscopy , 2005 .

[23]  A. Kahn,et al.  Electronic structure and current injection in zinc phthalocyanine doped with tetrafluorotetracyanoquinodimethane: Interface versus bulk effects , 2002 .

[24]  L. Lozzi,et al.  PbPC growth on Si surfaces studied with XPS and various SPM techniques , 1997 .

[25]  S. Forrest,et al.  A metal-free, full-color stacked organic light-emitting device , 1999 .

[26]  A. Goldoni,et al.  Phase separation in potassium-doped ZnPc thin films. , 2007, The Journal of chemical physics.

[27]  A. Morpurgo,et al.  Electronic Transport through Electron‐Doped Metal Phthalocyanine Materials , 2004, cond-mat/0401036.

[28]  N. Motta,et al.  Copper phthalocyanine on Si(111)-7 × 7 and Si(001)-2 × 1: an XPS/AES and STM study , 1994 .

[29]  Yi Luo,et al.  Equivalent core-hole time-dependent density functional theory calculations of carbon 1s shake-up states of phthalocyanine , 2004 .