Calculating Optical Absorption Spectra of Thin Polycrystalline Organic Films: Structural Disorder and Site-Dependent van der Waals Interaction
- We propose a new approach for calculating the change of the absorption spectrum of a molecule when moved from the gas phase to a crystalline morphology. The so-called gas-to-crystal shift Delta epsilon(m) is mainly caused by dispersion effects and depends sensitively on the molecules specific position in the nanoscopic setting. Using an extended dipole approximation, we are able to divide Delta epsilon(m)= -QW(m) in two factors, where Q depends only on the molecular species and accounts for all nonresonant electronic transitions contributing to the dispersion while W-m is a geometry factor expressing the site dependence of the shift in a given molecular structure. The ability of our approach to predict absorption spectra is demonstrated using the example of polycrystalline films of 3,4,9,10-perylenetetracarboxylic diimide (PTCDI).
Author details: | Jörg MegowGND, Thomas Körzdörfer, Thomas Renger, Mino Sparenberg, Sylke BlumstengelGND, Fritz Henneberger, Volkhard May |
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DOI: | https://doi.org/10.1021/acs.jpcc.5b01587 |
ISSN: | 1932-7447 |
Title of parent work (English): | The journal of physical chemistry : C, Nanomaterials and interfaces |
Publisher: | American Chemical Society |
Place of publishing: | Washington |
Publication type: | Article |
Language: | English |
Year of first publication: | 2015 |
Publication year: | 2015 |
Release date: | 2017/03/27 |
Volume: | 119 |
Issue: | 10 |
Number of pages: | 5 |
First page: | 5747 |
Last Page: | 5751 |
Funding institution: | Deutsche Forschungsgemeinschaft [Sfb 951, ME 4215/2-1]; Austrian Science Fund (FWF) [P24774-N27] |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
Peer review: | Referiert |