Computational and Monte Carlo simulation of quinoxaline-based organic dyes on TiO 2 for enhanced dye-densitized solar cell performance

This study employs DFT and TD-DFT methods to investigate the electronic, optical, and interfacial properties of quinoxaline-based organic dyes (C1–C5) for dye-sensitized solar cells. All dyes exhibit suitable energy-level alignment with TiO2 and the electrolyte redox potential, supporting efficient electron injection and dye regeneration. Reactivity descriptors identify C4 as the most reactive dye, while frontier molecular orbitals, TDM, and electrostatic potential analyses confirm efficient intramolecular charge transfer, particularly for C2 and C5. Adsorption and PDOS analyses reveal stronger dye–TiO2 interactions for C2, C3, and C5, identifying them as promising DSSC sensitizers.