Synthesis and Photovoltaic Investigation of Novel Triphenylamine- and Phenothiazine-Appended 1H-Pyrazole-3,4-Dicarboxylic Acid Dyes for Dye-Sensitized Solar Cells.

In the present study, we employed a comprehensive multi-step synthetic methodology to design and develop two novel organic dyes, TP-CLN and PT-CLN, using sydnone as a synthon. These compounds feature a donor-π-acceptor (D-π-A) architecture and are classified as chalcones. The resulting molecules were intricately attached to one-dimensional cadmium sulfide nanowires (1D CdS NWs), functioning as highly efficient light energy harvesters for dye-sensitized solar cells (DSSCs). The process of anchoring the dye onto the nano-network of CdS NWs was accomplished using simple solution chemistry, which proved to be both straightforward and efficient. We assessed the sensitizing capabilities of the synthesized materials through various methods, including optical and electrochemical investigations, density functional theory (DFT) simulations, and comprehensive photovoltaic assessments. A detailed analysis of the Dye-Sensitized Solar Cells containing PT-CLN revealed a photovoltaic efficiency 3.35 times higher (0.342%) than that of bare CdS NWs (0.102%) under standard light illumination. Similarly, the use of TP-CLN demonstrated a significant 3.08-fold improvement (0.314%) in photovoltaic efficiency. These results not only provide strong empirical support for the enhancement of external quantum efficiency (EQE) but also show a remarkable consistency with findings from optical examinations.