Toxicología ambiental y analítica

Asphaltene as Light Harvesting Material in Dye-Sensitized Solar Cell: Resurrection of Ancient Leaves

Abstract

Abujnah RE, Sharif H, Torres B, Castillo K, Gupta V and Chianelli RR

Asphaltenes are remnants of ancient photosynthetic plants and are today considered waste hydrocarbons that must be removed from petroleum for use as fuel and often find their use as road tar. This study reports the first time their use in Dye-Sensitized Solar Cells (DSSCs) in which light is converted to electricity with conversion efficiencies approaching 1.8%. Extracted fractions of asphaltenes from Mexican Altamira crude oil were used as light absorbers in TiO2 based DSSCs. The photovoltaic performances of the cells were analyzed by determining the I-V cell parameters such as OCV (open-circuit voltage), SCC (short-circuit current), FF (fill factor), and SR (series resistance). The overall energy conversion efficiency was also measured to correlate the effect of the different asphaltene portions that created significant improvement of the solar cell parameters. The sensitization of TiO2 electrode with the best asphaltene fraction resulted in a maximum energy conversion efficiency of 1.8% for the solar cell with a maximum photocurrent density of 16.9 mA/cm2. At this level the solar cell created has strong economic potential. A future strategy to further improve performance by minimizing series resistance and improving the photo current and open circuit voltage is also reported. The cells have shown excellent life as suggested by photo-catalytic polymerization of asphaltene materials when exposed to sunlight and air as stated in patent number 8,389,853.