AVS 58th Annual International Symposium and Exhibition | |
Surface Science Division | Tuesday Sessions |
Session SS+EM-TuA |
Session: | Organic Electronic Interfaces |
Presenter: | Oliver Monti, University of Arizona |
Authors: | O.L.A. Monti, University of Arizona M.P. Steele, University of Arizona N. Ilyas, University of Arizona L.L. Kelly, University of Arizona D.A. Racke, University of Arizona |
Correspondent: | Click to Email |
We present an investigation of the evolution of the electronic structure at the interface of the dipolar organic semiconductor vanadyl naphthalocyanine with both highly oriented pyrolytic graphite and Au (111). Using angle-resolved two-photon photoemission and other photoelectron spectroscopies we observe both excitonic as well as strictly interfacial states in both ground and excited state manifolds, with large differences between the two surfaces. Simple electrostatic considerations provide a chemisorption model that is capable of quantitatively describing long- and short-range interface-mediated intermolecular coupling, significantly altering the molecular electronic structure. Additional insights are available from full-scale first-principles calculations at these interfaces. As a consequence, we show that electrostatic multipoles can significantly influence molecular and interfacial electronic structure, with direct and observable impact on interfacial charge-transfer dynamics. Interfacial electrostatic fields may therefore be used to manipulate in a concrete fashion processes of critical importance to solar energy conversion such as photoinduced interfacial electron transfer.