Photoluminescence spectroscopy of pure pentacene, perfluoropentacene and mixed thin films

Abstract

We report detailed temperature dependent photoluminescence (PL) spectra of pentacene (PEN), perfluoropentacene (PFP), and PEN:PFP mixed thin films grown on SiO2. PEN and PFP are particularly suitable for this study, since they are structurally compatible for good intermixing and form a model donor/acceptor system. The PL spectra of PEN are discussed in the context of existing literature and compared to the new findings for PFP. We analyze the optical transitions observed in the spectra of PEN and PFP using time-dependent density functional theory (TD-DFT) calculations. Importantly, for the mixed PEN:PFP film we observe an optical transition in PL at 1.4 eV providing evidence for coupling effects in the blend. We discuss a possible charge-transfer (CT) and provide a tentative scheme of the optical transitions in the blended films.

9 pages, 6 figures, accepted for publication in J. Chem. Phys

References in corpus (3)

• Morphology Effectively Controls Singlet-Triplet Exciton Relaxation and Charge Transport in Organic Semiconductors
• Optical Properties of Pentacene and Perfluoropentacene Thin Films
• Optical evidence for intermolecular coupling in mixed films of pentacene and perfluoropentacene

Cited by in corpus (8)

• Ultrafast Exciton Dissociation and Long-Lived Charge Separation in a Photovoltaic Pentacene MoS2 van der Waals Heterojunction
• Vibronic exciton theory of singlet fission. I. Linear absorption and the anatomy of the correlated triplet pair state
• Vibronic exciton theory of singlet fission. II. Two-dimensional spectroscopic detection of the correlated triplet pair state
• Theory of Triplet Optical Absorption in Oligoacenes: From Naphthalene to Heptacene
• 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
• Thin Film Growth of Phase-Separating Phthalocyanine-Fullerene Blends: A Combined Experimental and Computational Study
• Monolayer and bilayer perfluoropentacene on Cu(111)