Excited States Dynamics at Pentacene/Perfluoropentacene Interfaces: A Femtosecond Time‐Resolved Second Harmonic Generation Study

• DOI: 10.1002/cphc.202300904
• Publication Date: 2024-02-02T11:56:15Z
• Authors: Vipilan Sivanesan; Katharina Broch; Petra Tegeder
• Keywords: Pentacene; Picosecond; Acceptor

Understanding the dynamics of excited states after optical excitation at donor-acceptor (D/A) interfaces is paramount importance for improving efficiency and performance optoelectronic devices. Here, we studied ultrafast state between electron donor (D) pentacene (PEN) acceptor (A) perfuoropentacene (PFP) as well within single compounds (PEN PFP) using femtosecond (fs) time-resolved second harmonic generation (SHG). In singlet fission observed on a time scale around 200 fs. bilayer systems huge SHG intensity rise due to creation charge transfer interface accordingly formation local electric field tens picoseconds. The therefore signal from PEN/PFP much more intense compared PFP/PEN system because PFP PEN intermixing higher. Accordingly population defect 55±12 ps has been proposed PEN/PFP. Our study provides important insights into D/A properties, which needed understanding interfacial photophysics pentacene-based organic compounds.