Enhanced Chlorophyll A Purification and Dye Sensitized Solar Cell Performance

摘要

Dye-sensitized solar cells (DSSC) may provide an economical alternative to the present p-n junction photovoltaic devices. Here the relation between chlorophyll purity and photovoltaic performance was examined. Also the commercial grade copper chlorophyll was examined. The performance under simulated sunlight and the quantum efficiency were measured. All samples had large short wavelength quantum efficiency however the high purity chlorophyll had larger quantum efficiency in the visible. The highest purity samples produced DSSC solar cells with the highest open circuit voltage and efficiency while the fill factor and the short circuit current were not strongly correlated with purity. The un-altered short circuit current suggests that chlorophyll attachment and charge transfer at the titanium oxide are not altered by impurities. However the results suggest that impurities (and/or copper in the commercial chlorophyll case) alter the photo-absorption and the electrolyte so as to either change the iodine chemical potential or decrease the diffusivity of iodine ions.