Influence of illumination spectra on DSSC performance

The possibility to create dye-sensitized solar cells (DSSCs) using nontoxic and inexpensive materials under usual lab or industrial conditions, i.e. without a cleanroom, has aroused large interest in this technology during the last decades. DSSCs are known to function well in low light or diffuse light conditions. Therefore, they could be interesting for indoor use, where the ambient light may have different spectra. In DSSCs, the visible light is absorbed by a dye molecule. The efficiency is affected by the overlapping grade of the maxima in the dye absorption spectrum and in the illumination spectrum, i.e. through an appropriate choice of dye, the efficiency can be maximized for each illumination condition. In this study the effect of the illumination spectra on the energy-conversion efficiency was investigated. DSSCs built using anthocyanin dyes were illuminated by a halogen lamp and an LED lamp with color temperatures of 3000 K and 5000 K, respectively, in combination with color filters or without them. Depending on the illumination spectra, the efficiency of the cell was found to vary between 0.06% and 0.33%, pointing out the importance of tailoring the DSSCs for the planned application.