Optoelectronic and Photophysical Properties of Azo-Schiff Base Dyes: Experimental and DFT Insights for Dye-Sensitized...

A series of azo group containing Schiff base dyes (1-4) were synthesized. Dye structures were characterized by ¹³C-NMR, ¹H-NMR, FTIR, UV-Visible and elemental analysis. The geometrical structures of the molecules were optimized using density functional theory (DFT) implemented in the Gaussian 16 W software. In this study, the cell performances of four different Schiff-base organic dyes in dye-sensitized solar cells (DSSCs) were comparatively evaluated. Semiconductor TiO₂ powder was used as the working electrode and graphite powder was used as the counter electrode. Photovoltaic performances of the produced cells were investigated by I-V characteristic measurements under sunlight and energy conversion efficiency (η) and fill factor (FF) were calculated for each dye. According to the obtained results, the efficiency values for dyes numbered 1, 2, 3 and 4 were determined as 0.46%, 0.76%, 0.56% and 1.07%, respectively. FF values for the same dyes were found to be 0.39, 0.42, 0.36 and 0.47, respectively. The results indicate that the structural properties of Schiff-base dyes play an important role in DSSC performance and such dyes can be used in low-cost solar cell applications with appropriate design.