An Iron‐Based Photosensitizer with Extended Excited‐State Lifetime: Photophysical and Photovoltaic Properties

Herein, we report a homoleptic iron complex bearing tridentate bis‐carbene (CNC) ligands designed for sensitization of TiO 2 photoanodes. Its excited state has been characterized by ultra‐fast transient spectroscopy and time‐dependent density functional theory (TD‐DFT) computations, which reveal a record triplet metal‐to‐ligand charge‐transfer ( 3 MLCT) excited‐state lifetime (16 ps). The new dye was efficiently chemisorbed on TiO 2 and promoted electron injection and photocurrent generation in a dye‐sensitized solar cell upon solar irradiation.