Natural dyes as photosensitizers for dye-sensitized solar cell

The dye-sensitized solar cells (DSC) were assembled by using natural dyes extracted from black rice, capsicum, erythrina variegata flower, rosa xanthina, and kelp as sensitizers. The I-SC from 1.142 mA to 0.225 mA, the V-OC from 0.551 V to 0.412 V, the fill factor from 0.52 to 0.63, and P-max from 58 mu W to 327 mu W were obtained from the DSC sensitized with natural dye extracts. In the extracts of natural fruit, leaves and flower chosen, the black rice extract performed the best photosensitized effect, which was due to the better interaction between the carbonyl and hydroxyl groups of anthocyanin molecule oil black rice extract and the surface of TiO2 porous film. The blue-shift of absorption wavelength of the black rice extract in ethanol solution on TiO2 film and the blue-shift phenomenon from absorption spectrum to photoaction spectrum of DSC sensitized with black rice extract are discussed in the paper. Because of the simple preparation technique, widely available and low cheap cost natural dye as an alternative sensitizer for dye-sensitized solar cell is promising. (c) 2005 Elsevier Ltd. All rights reserved.