Investigation of pigments extracted from Phytolacca americana plant for applications in dye-sensitized solar cells

Natural dyes extracted from fruit (FPA) and stalk (SPA) of pokeweed (Phytolacca americana) were used as photosensitizers for dye-sensitized solar cells (DSSCs). All the extracts were employed without any modifications, such as purifications or addition of stabilizers. Betalain and prebetanin were identified as the main components for FPA and SPA extracts. SPA and FPA displayed broader absorption spectra, which is beneficial to light harvesting capability. When tested in DSSCs, the highest power conversion efficiency (PCE) of 3.04% is obtained by SPA, and this followed by PCEs of 2.97, for FPA. On the other hand, after 120 h of sunlight irradiation, FPA and SPA retained the PCE values as 63% and 69% of the initial efficiencies.