Effect of Structural and Material Modifications of Dye-Sensitized Solar Cells on Photovoltaic Performance

Dye-sensitized solar cells with synthesized phenothiazine derivative 3,7′-bis(2-cyano-1-acrylic acid)-10-ethyl-phenothiazine (PTZ) and commercial di-tetrabutylammonium cis-bis(isothiocyanato)bis(2,2′-bipyridyl-4,4′-dicarboxylato)ruthenium(II) (N719) dyes were fabricated and characterized based on current–voltage measurements. The effect of the utilization of individual dyes and its mixture, chenodeoxycholic acid as co-adsorbent addition, replacement of I−/I3− by Co2+/3+ ions in electrolyte and platinum by semiconducting polymer mixture poly(3,4-ethylenedioxythiophene) polystyrene sulfonate in counter electrode was studied. Additionally, the effect of polymer thickness on the photovoltaic performance of the device was evaluated. Prepared photoanodes were characterized by UV–Vis spectroscopy and atomic force microscopy. The further modification of DSSCs involving the fabrication of tandem solar cells was carried out. The higher power conversion efficiency 7.60% exhibited tandem photovoltaic cell sensitized with dyes mixture containing co-adsorbent, I−/I3− ions in the electrolyte, and platinum in the electrode.