Study of chlorophyll dye from peppermint ( mentha spicata ) used as a sensitizer in TiO 2 solar cells

Chlorophyll from peppermint ( mentha spicata ) was evaluated as a natural dye sensitizer in TiO 2 solar cells. The final photoconversion efficiency depended on the solvent used as chlorophyll dispersant and the technique used to sensitize the mesoporous TiO 2 film. Evaluated sensitization techniques included pipetting, immersion, and electrophoresis. Best solar cell performance was obtained using methanol as solvent simultaneously with electrophoresis. A short circuit current density ( J sc ) of 0.174 mA/cm 2 and an open circuit voltage ( V oc ) of 0.508 V were obtained. The photoconversion efficiency reached 0.39 %. However, sensitizing by the pipetting technique allowed a photoconversion efficiency of 0.35 % with better reproducibility.