Electrolyte-Free Dye-Sensitized Solar Cell with High Open Circuit Voltage Using a Bifunctional Ferrocene-Based Cyanovinyl Molecule as Dye and Redox Couple

Functionalization of ferrocenyl moieties with a cyanovinyl system using a unique solid-state synthetic method led to the formation of donor–acceptor type compounds with wide absorption in the visible region. A DSSC study using the ferrocenyl cyanovinyl compound as a dye with an electrolyte-free fabrication system showed an unprecedented open-circuit voltage (V_OC) of 763–841 mV. DFT calculations were carried out to understand an unique electron transfer mechanism for the DSSC device which may be responsible for the high V_OC.