Commercial and natural dyes as photosensitizers for a water-based dye-sensitized solar cell loaded with gold nanoparticles

We fabricated gold nanoparticles as a Schottky barrier on a TiO2 electrode, which adsorbed the commercial dyes and free natural dyes in the water-based dye-sensitized solar cell (water-based DSSC) with the aqueous electrolyte of Ce4+/3+ system. Conversion of visible light into electricity was accomplished with natural dyes, resulting in excellent photoelectric properties compared to those achieved with commercial dyes. The extracts of the natural dye Rhoeo spathacea (Sw.) Stearn. can reach the solar conversion efficiency of 1.49%, which had the best photosensitized effect of the water-based DSSC. Due to the simple preparation technique, wide availability and low cost, natural dyes are promising as environmentally friendly alternative sensitizers for water-based DSSC. (C) 2007 Elsevier B.V. All rights reserved.