Effect of flower extracts on the photoconversion efficiency of dye sensitized solar cells fabricated with Sn-doped TiO₂

Extensive efforts are being made in enhancing the photoconversion efficiency of TiO₂ based dye sensitized solar cells (DSSC) using different approaches. In this work, the Sn-doped TiO₂ nanopowder was sensitized with flower extracts of Dahlia Violet (DV), Rabbit flower (RF) and their mixed extract separately other than the commercial N719 dye and DSSC characteristics were studied. Hydrothermal method was used to synthesize Sn-doped TiO₂ for 48 h at 150 °C. X-ray diffraction, UV–Vis, FTIR and Raman scattering were used to characterize the synthesized powder. DSSCs of the synthesized powder was fabricated using conventional sandwich type technique sealed with Surlyn^® polymer film. The photocurrent–voltage characteristics were measured under solar simulated light using source-meter. It is interesting to note that the flower extract resulted in comparable photoconversion efficiency as that of N719 dye. When the powder was sensitized with N719, 1.66 % efficiency was achieved while mixed extract resulted in 1.28 %, DV in 0.99 % and RF in 0.52 % efficiency. The results of various analysis techniques and cell characteristics are correlated.