Novel Phenothiazine and Coumarin based Sensitizers: Design, Synthesis and Photoelectrochemical Application by Anchoring on CdS Nanowires

Novel metal-free organic dyes (E)-2-cyano-3-(10-(prop-2-yn-1-yl)-10H-phenothiazin-3-yl)acrylic acid (PPC) and (E)-2-cyano-3-(10-((1-((7-methyl-2-oxo-2H-chromen-4-yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)-4a,10a-dihydro-10H-phenothiazin-3-yl)acrylic acid (PCTC) was synthesized and then anchored to 1D cadmium sulfide nanowires (1D CdS NWs) for application in photoelectrochemical dye-sensitized solar cell (DSSC). The 1D CdS nanowires were interconnected into a nanonetwork using solution chemistry in a straightforward and efficient manner. The UV-visible spectroscopy, cyclic voltammetry and density functional theory (DFT) were effectively employed to analyze the characteristics of PPC and PCTC. The sensitizer-anchored CdS nanowires have a broader range of light absorption in the UV-visible spectrum compared to bare CdS nanowires. The complete device has the assembly FTO, compact CdS, CdS nanowires, synthesized dye and counter electrode. In photovoltaic assessment, the PCTC and PPC devices yield 3.19 and 3.04 times, respectively, more efficiency than naked CdS nanowires under conventional sunshine illumination (100 mW/cm2, AM 1.5G). The obtained results provide strong evidence supporting the presence of rising external quantum efficiency (EQE) and show a high level of consistency with the optical tests.