Investigation of Polaron Pair Dynamics in Poly(3-Hexylthiophene)...

Polaron pair dynamics in regioregular Poly (3-hexylthiophene) (RR-P3HT) film was studied by applying both femtosecond transient absorption and fluorescence up-conversion techniques. The comparison of the dynamics of the pure fluorescence, the ground state bleaching recovery and the polaron pair absorption reveals that the polaron pairs decay back to the ground state of certain morphological places with distinct absorption features, instead of the singlet excited state.