Following charge dynamics via their vibrational infrared response

Vibrational modes sensitive to charge-induced structural changes serve as indicators of picosecond charge dynamics in electronic-pump infrared-probe measurements. Thereby, the structural formation of a twisted intramolecular charge transfer state is observed in HTI photoswitches. Different polaronic charge carrier species are distinguished in photovoltaic materials via associated infrared-activated vibrations. Polaron and polaron pair dynamics are followed in conjugated polymers. Localiziation is observed for a subset of charge carriers in MaPbI${}_3$ perovskite.