Free-Standing Graphene/Conducting Polymer Hybrid Cathodes as FTO and Pt-Free Electrode for Quasi-State Dye Sensitized Solar Cells

Highly conducting freestanding graphene (FSG) was synthesized by the simple vacuum filtration method and utilized as a cathode current collector for (fluorine doped tin oxide) FTO free quasi-dye sensitized solar cell (q-DSSC). Subsequently, conducting polymers (CPs) viz., polyaniline (PANI) and poly(3,4-ethylene-di-oxythiophene) (PEDOT) was decorated on FSG surface by electrochemical polymerization which acts as a electrocatalytst for Pt free q-DSSC. Entirely, the FSG/CPs affords as a novel cathode architecture for FTO/Pt free electrode for q-DSSCs. Remarkably, the FSG paper electrode exhibits lower sheet resistance (9-11 Omega sq(-1)) than the FTO which was directly utilized as current collector. Interestingly, the FSG/CPs based cathode shows an improved electro-catalytic behaviour towards tri-iodide reduction and in particularly, the photovoltaic performance of FSG/PEDOT shows power conversion efficiency (PCE) of 5.4% compared with Pt/FTO of 5.1%. It can be stated that synergetic effect of FSG/PEDOT proves to be a cost effective and efficientsubstitute for cathodes in q-DSSC.