Proving weak electronic interaction between molecules and substrate: a study of pentacene monolayer on graphite

The impact of van der Waals interaction on the electronic structure between a pentacene monolayer and a graphite surface was investigated. Upon cooling the monolayer, newly formed dispersive bands, showing the constant final state nature overlapping with the non-dispersive, discrete molecular orbital state, is observed by low-energy angle-resolved photoelectron spectroscopy. The dispersive band consists of positive and negative intensities depending on the final state energy, indicating Fano resonance involving a discrete molecular state that couples a continuum state upon photoionization. A wave-function overlap is demonstrated according to their larger spread in unoccupied states even at the weakly bounded interface by Fano spectral analysis.

[1]  S. Kera,et al.  Sample-shape dependent energy levels in organic semiconductors , 2022, Physical Review B.

[2]  S. Suga,et al.  Valence Band Dispersion Embedded in Resonant Auger Electrons , 2021, Journal of the Physical Society of Japan.

[3]  M. Limonov.  Fano resonance for applications , 2021 .

[4]  F. Stefan Tautz,et al.  kMap.py: A Python program for simulation and data analysis in photoemission tomography , 2020, Comput. Phys. Commun..

[5]  秀樹 石津,et al.  Interface , 2021, Thailand.

[6]  Takashi Yamada,et al.  Hybridization of an unoccupied molecular orbital with an image potential state at a lead phthalocyanine/graphite interface , 2018, Journal of physics. Condensed matter : an Institute of Physics journal.

[7]  A. Schöll,et al.  Molecular orbital imaging beyond the first monolayer: Insights into the pentacene/Ag(110) interface , 2018, Physical Review B.

[8]  I. Hamada,et al.  Hybrid image potential states in molecular overlayers on graphene , 2017 .

[9]  Y. Nakayama,et al.  Single-Crystal Pentacene Valence-Band Dispersion and Its Temperature Dependence. , 2017, The journal of physical chemistry letters.

[10]  N. Ueno,et al.  Photoelectron spectroscopy on the charge reorganization energy and small polaron binding energy of molecular film , 2015 .

[11]  I. Hamada.  van der Waals density functional made accurate , 2014 .

[12]  Christian Eickhoff,et al.  Two-state double-continuum Fano resonance at the Si(100) surface. , 2011, Physical review letters.

[13]  S. Menon,et al.  Unoccupied electronic structure of graphite probed by angle-resolved photoemission spectroscopy , 2011 .

[14]  D. Käfer,et al.  Growth and structure of pentacene films on graphite: Weak adhesion as a key for epitaxial film growth , 2010 .

[15]  Stephen Berkebile,et al.  Reconstruction of Molecular Orbital Densities from Photoemission Data , 2009, Science.

[16]  T. Shimada,et al.  Band dispersion of quasi-single crystal thin film phase pentacene monolayer studied by angle-resolved photoelectron spectroscopy , 2009 .

[17]  N. Ueno,et al.  First-principles measurements of charge mobility in organic semiconductors: Valence hole―vibration coupling in organic ultrathin films , 2009 .

[18]  Satoshi Kera,et al.  Electron spectroscopy of functional organic thin films: Deep insights into valence electronic structure in relation to charge transport property , 2008 .

[19]  J. Brédas,et al.  Electronic and vibronic interactions at weakly bound organic interfaces : The case of pentacene on graphite , 2008 .

[20]  Tadaaki Nagao,et al.  Electronic structures of the highest occupied molecular orbital bands of a pentacene ultrathin film. , 2007, Physical review letters.

[21]  V. May,et al.  Theory of ultrafast heterogeneous electron transfer: contributions of direct charge transfer excitations to the absorbance. , 2007, The Journal of chemical physics.

[22]  Hirohiko Fukagawa,et al.  Hole-vibration coupling of the highest occupied state in pentacene thin films , 2005 .

[23]  N. Ueno,et al.  Very narrow photoemission bandwidth of the highest occupied state in a copper-phthalocyanine monolayer , 2002 .

[24]  V. Weisskopf,et al.  Effects of Configuration Interaction on Intensities and Phase Shifts , 2001 .

[25]  P. Blaha,et al.  Three-dimensional unoccupied band structure of graphite: Very-low-energy electron diffraction and band calculations , 2000 .

[26]  B. Delley,et al.  Observation of a Fano resonance in photoemission , 1999 .

[27]  Kresse,et al.  Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. , 1996, Physical review. B, Condensed matter.

[28]  G. Kresse,et al.  Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set , 1996 .

[29]  Blöchl,et al.  Projector augmented-wave method. , 1994, Physical review. B, Condensed matter.

[30]  Hafner,et al.  Ab initio molecular-dynamics simulation of the liquid-metal-amorphous-semiconductor transition in germanium. , 1994, Physical review. B, Condensed matter.

[31]  Hafner,et al.  Ab initio molecular dynamics for liquid metals. , 1995, Physical review. B, Condensed matter.

[32]  Suzuki,et al.  Unoccupied-electronic-band structure of graphite studied by angle-resolved secondary-electron emission and inverse photoemission. , 1988, Physical review. B, Condensed matter.

[33]  Svensson,et al.  Observation of autoionizing resonances in core electron shakeup spectra. , 1987, Physical review letters.

[34]  Schaefer,et al.  Conduction-band structure of graphite studied by combined angle-resolved inverse photoemission and target current spectroscopy. , 1987, Physical review. B, Condensed matter.

[35]  Takahashi,et al.  Angle-resolved ultraviolet photoelectron spectroscopy of the unoccupied band structure of graphite. , 1985, Physical review. B, Condensed matter.

[36]  H. Schroder,et al.  Resonant vacuum ultraviolet photoemission of atomic Fe, Co and Ni , 1983 .