Tuning of optoelectronic properties of triphenylamines-based donor materials for organic solar cells

In the present study, four molecules have been designed by substituting various acceptor moieties around the triphenylamine donor moiety like 2-cyano acrylic acid (R), 2-methylene malonitrile (M1), 2-cyano acrylic acid methyl ester(M2), 2-(2-methylene-3-oxo-indan-1-ylidene)-malonitrile (M3), 2-(6,7-difluoro-2-methylene-3-oxo-indan-1-ylidene)-malonitrile (M4), respectively. CAM-B3LYP/6-31G (d, p) level of theory by using density functional theory (DFT) has been used for the investigation of optoelectronic properties of four new triphenylamine (TPA)-based donor materials (M1–M4) for organic solar cells. In comparison with the recently reported reference molecule, the optoelectronic properties of designed molecules were evaluated. M4 showed absorption maxima at 520[Formula: see text]nm due to extended conjugation with bridged thiophene group. Results of reorganization energy calculations also favor M4 exhibiting highest transfer rate of hole as depicted from its low reorganization energy of hole ([Formula: see text].