Photophysical insights into TFHA-OP: Optimizing Optical Performance Through Solvent and Film Thickness Control

Conjugated organic semiconductors with donor-it-acceptor (D-it-A) structures are pivotal for optoelectronic applications. This study investigates the optical properties of 2-(4-trifluoromethylphenyl)-3-(4-hydroxyphenyl) acrylonitrile (TFHA-OP), focusing on solvent and film thickness effects.UV-Vis spectroscopy shows that DMSO reduces the optical band gap t o 3.107 eV, compared to acetone, while increasing film thickness further lowers the band gap to 2.965 eV at 28.7 mu m, alongside an enhanced refractive index. TD-DFT and HOMO-LUMO analysis support these findings, confirming significant solvent and thickness dependence. Importantly, this study evaluates the nonlinear optical (NLO) properties in solution for the first time, revealing that DMSO significantly boosts beta tot by 2.7-fold. These findings underscore TFHA-OP's strong light-matter interaction in thin films, positioning it as a promising candidate for efficient, low-cost, and flexible optoelectronic devices, such as photovoltaics and sensors.