Computational investigation of charge transfer mechanisms in dye-sensitized solar cells: unraveling the influence of anchoring groups in 2-styryl-5-phenylazo-pyrrole designed dyes

The proposed dyes demonstrated characteristics conducive to achieving high-power conversion efficiency (PCE) in dye-sensitized solar cells (DSSCs). Novel azo dyes diverse anchoring groups, including carboxylic acid, carboxylic diacid, biscarbodithiolic acid, phosphonic acid, and sulfonic acid, were examined to assess their impact on electronic and optical properties within DSSCs. A computational investigation was conducted to design and evaluate charge transfer mechanisms using azo-pyrrole-based dyes for DSSCs performed with the Gaussians 09 and employing TD-DFT techniques with functions like B3LYP and a 6-31G (d, p) basis set to analyze ground and excited state characteristics. Enhanced charge transfer was observed due to improved molecular properties within DSSCs. The analysis encompassed electronic and optical properties, UV-Vis absorption spectra, light harvesting efficiency, and hardness to elucidate the effects of various anchoring groups. Carboxylic acid-based dyes exhibited broad absorption spectra, the longest maximum wavelength, and the highest light harvesting efficiency, indicating proficient electron injection capabilities.