Optical evidence for intermolecular coupling in mixed films of pentacene and perfluoropentacene

Abstract

We present optical absorption spectra of mixed films of pentacene (PEN) and perfluoropentacene (PFP) grown on SiO2. We investigated the influence of intermolecular coupling between PEN and PFP on the optical spectra by analyzing samples with five different mixing ratios of PFP:PEN with variable angle spectroscopic ellipsometry (VASE) and differential reflectance spectroscopy (DRS). The data show how the spectral shape is influenced by changes in the volume ratio of the two components. By comparison with the pure film spectra an attempt is made to distinguish transitions due to intermolecular coupling between PEN and PFP from transitions caused by interactions of PEN (PFP) with other molecules of the same type. We observe a new transition at 1.6 eV which is not found in the pure film spectra and which we assign to coupling of PFP and PEN.

arXiv comment6 pages, 6 figures, 1 table, accepted for publication in Phys. Rev. B

References in corpus (1)

• Optical Properties of Pentacene and Perfluoropentacene Thin Films

Cited by in corpus (4)

• Photoluminescence spectroscopy of pure pentacene, perfluoropentacene and mixed thin films
• Mixing-induced anisotropic correlations in molecular crystalline systems
• Molecular Packing Motifs Determine Charge-Transfer and Carrier Dynamics in Molecular Heterosystems: the Case of Pentacene - Perfluoropentacene
• Polarization Resolved Optical Excitation of Charge-Transfer Excitons in PEN:PFP Co-Crystalline Films: Limits of Non-Periodic Modelling