Application and characterization of blueberry fruit pigment as photosensitizer for high performance and stable natural dye sensitized solid state solar cells

The natural dye pigment of blueberry was extracted from its peals using acetonitrile as solvent. This dye was used in a liquid electrolyte-free, natural dye-sensitized solid solar cell (NDSSSC). Natural dyes are inexpensive, non-toxic and are reliable and redily available sources of dyes. However, the typical problem associated with them is their instability towards iodide/tri-iodide electrolyte. This was addressed by introducing p-CuI as the hole-conductor in place of iodide/tri-iodide electrolyte. The hole conductor was applied on dyed nonporous TiO₂ films from a solution containing a crystal growth inhibitor triethylammium thiocyanate (THT) using drop-casting method. I-V characteristics and impedance measurements were carried out to   investigate the photovoltaic performance and further characterized by UV-Visible spectroscopy, FTIR spectroscopy and SEM.  to achieve a highest efficiency(ɳ) of 1.7% with a short circuit current density (Jsc) of 11 mA cm^-2, open circuit voltage (Voc) of 0.30 V and fill factor (ff) of 51.8. These are the highest recorded values so far achieved for such solar cells. Stability measurements were carried out for a period of 30 days and promisingly showed a good stability over the liquid type natural dye sensitised solar.