Effect of Anchoring Groups Number on the Photovoltaic Parameters in Dye-Sensitized Solar Cells

Abstract

We have developed a series of Ru-Sensitizers (GS16, GS17, and GS19) with molecular architecture containing a tridentate ligand with one, two, and three anchoring groups and three thiocyanates. Furthermore, we have studied the effect of the number of carboxylic groups on photovoltaic properties. The absorption spectra of the novel sensitizers extended up to the red region (900 nm). The electrochemical studies reveal that the oxidation potentials are aligned below the iodine-based redox potential, feasible for easy regeneration and the LUMO of all sensitizers lie above the TiO2 conduction band, which is a favour for easy electron injection. The overall efficiency (η) of the GS16, GS17, and GS19 is 1.13%, 2.71%, and 1.59% with short circuit current (JSC) of 3.74 mA cm−2, 7.08 mA cm−2, 6.27 mA cm−2, open-circuit voltage (VOC) of 0.42 V, 0.54 V and 0.39 V and fill factor (FF) of 0.70, 0.70 and 0.65 respectively. The highest efficiency of 2.71% was observed in GS17, bearing the two anchoring groups compared to one and three carboxylic acid-containing sensitizers (GS16 and GS19). Theoretical studies are also examined and matched with the experimental data.