Studies on DSSC encompassing flower shaped assembly of Na-doped TiO2 nanorods sensitized with extract from petals of Kigelia Africana

Flower of Kigelia Africana constitute anthoyanin as a predominant flavonoid pigment and are responsible for absorption of light in visible region. In the present study, the extract of this flower is used as sensitizer for DSSC. Na-doped TiO2 nanorods have been synthesized via one step hydrothermal method and used as photoanode. XRD analysis of Na-doped TiO2 nanorod samples revealed the formation of single rutile phase structure. FESEM images revealed the formation of nanorods and overgrowth of nanoflowers on increasing the amount of the dopant. The photoelectric conversion efficiency of DSSC increased from 1.09% to 1.56% when compared to undoped TiO2 based DSSC that exhibited an efficiency of 0.87%. A relatively high open circuit voltage was obtained because of nanorods structure and doping technique. The downward shift of flat band voltage with Na-doped TiO2 improved the driving force for electron injection, leading to the enhanced photocurrent density.