New organic dyes based on phenylenevinylene for solar cells: DFT and TD-DFT investigation

In this work, we report five novel organic dyes with donor-π-acceptor (D-π-A) structure, their conjugated bridge is based on phenylenevinylene and thiophene/furan, the acid 2-cyanoacrylic was used as an electron acceptor (anchoring) group and triphenylamine was used as an electron donor group for all compounds. These dyes were studied by Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) methods using Becke's three-parameter functional and Lee-Yang-Parr functional (B3LYP) level with 6-31G(d) basis set to investigate their molecular structures, frontier molecular orbitals, optoelectronic properties and absorption spectra as implemented in the Gaussian 09 program. The HOMO (highest occupied molecular orbital), LUMO (lowest unoccupied molecular orbital) levels, gap energy (EHOMO - ELUMO) and Voc (open-circuit voltage) of the studied compounds are calculated and discussed. These properties suggest that these compounds as good candidates for use in organic dye-sensitized solar cells.