Polyethyleneoxide (PEO)-based, anion conducting solid polymer electrolyte for PEC solar cells

Paper in proceeding, 2008

Solid polymer electrolyte membranes were prepared by complexing tetrapropylammoniumiodide (Pr4N+I-) salt with polyethylene oxide (PEO) plasticized with ethylene carbonate (EC), and these were used in photoelectrochemical (PEC) solar cells fabricated with the configuration glass/FTO/TiO2/dye/electrolyte/Pt/FTO/glass. The PEO/Pr4N+I-+I-2=9:1 ratio gave the best room temperature conductivity for the electrolyte. For this composition, the plasticizer EC was added to increase the conductivity, and a further conductivity enhancement of four orders of magnitude was observed. An abrupt increase in conductivity occurs around 60-70 wt% EC; the room temperature conductivity was 5.4 x 10(-7) S cm(-1) for 60 wt% EC and 4.9 x 10(-5) S cm(-1) for the 70 wt% EC. For solar cells with electrolytes containing PEO/Pr4N+I-+I-2=9:1 and EC, IV curves and photocurrent action spectra were obtained. The photocurrent also increased with increasing amounts of EC, up to three orders of magnitude. However, the energy conversion efficiency of this cell was rather low.