Acceptors/linkers effects on dye sensitized solar cell: Theoretical investigations of structure-property relationship for design of efficient dye sensitizers

A series of carbazole-based organic dyes such as CzFCA, CzTCA, CzSeCA, CzFRA, CzTRA and CzSeRA with introduction of various linkers (furan, thiophene and selenophen) and acceptor (cyanoacrylic acid and rhodanine-3-acetic acid) groups, were designed and theoretically investigated by density functional theory (DFT) and time dependent DFT (TD-DFT). The ground state structures and absorption spectra (both in vacuum and solvated form) were optimized by using DFT-B3LYP/6-31G(d,p), TD-B3LYP/6-311G(d,p) and PCM-TDB3LYP/ 6-311G(d,p) levels of theory. Substitution of linker groups from furan to selenophen, resulted in red-shift of absorption band. CzTRA and CzSeRA exhibited superior electron injection capabilities. The finding of this study can be helpful to obtain dye-sensitized solar cell (DSSC) with superior conversion efficiency.