Ultrafast Charge Carrier Dynamics in Diketopyrrolopyrrole-Linked Tetrabenzoporphyrin Films Studied by Time-Resolved Terahertz Spectroscopy

We use time-resolved terahertz (THz) spectroscopy to study the charge carrier dynamics of diketopyrrolopyrrole-linked tetrabenzoporphyrin (C4-DPP-BP) thin films and C4-DPP-BP:PC₆₁BM bulk heterojunction (BHJ) thin films. For BHJ thin films, the results show that the amplitude of the picosecond decaying components depends on the excitation fluence. We consider that the annihilation of charge pairs is responsible for the fast decaying components in the BHJ thin film at higher excitation fluence.