Natural Dyes Extracted from Black Carrot and Bramble for Dye-Sensitized Solar Cells

Two different natural dyes containing anthocyanin extracted from black carrot and bramble from Iran. Spectrophotometric evaluations of the natural dyes in solution and on a TiO2 substrate were carried out in order to assess changes in the status of the natural dyes. The results show that the natural dyes indicate bathochromic shift on the TiO2 substrates. The chemical adsorption of natural dyes present at the surface of TiO2 substrate that their chemical binding can be increased by the chelating effect to the Ti(IV) ions. Finally, dye sensitized solar cells were fabricated in order to determine the photovoltaic behavior and conversion efficiencies of each dyes and mixture of extracts. Such evaluations demonstrate conversion efficiencies of 0.33%, 0.69% and 0.47% for black carrot, bramble and mixed extract, respectively. Natural dyes are suitable alternative photosensitizers for dye-sensitized solar cells due to simple preparation method, low cost, environmentally friendly and widely available. Prog. Color Colorants Coat. 8 (2015), 153-158 © Institute for Color Science and Technology.