Cationic effect on dye-sensitized solar cell properties using electrochemical impedance and transient absorption spectroscopy techniques

Redox-couple polymer electrolytes, (poly(ethylene oxide)-succinonitrile) blend/MI-I-2, where M = Li or K, were prepared by the solution cast method. Owing to the plasticizing property of K+ ions, the K+ ion-based electrolyte exhibited better electrical conductivity than the Li+ ion-based electrolyte, which did however exhibit better photovoltaic properties. Electrochemical impedance spectroscopy revealed faster redox species diffusions and interfacial processes in the Li+ ion-based dye-sensitized solar cells than in the K+ ion-based ones. Transient absorption spectroscopy ascertained faster dye-regeneration by the Li+ ion-based electrolyte than the K+ ion-based electrolyte.