NEW ORGANIC MATERIALS BASED ON THIADIAZOLOTHIENOPYRAZINE–DITHIOPHENE FOR PHOTOVOLTAIC APPLICATIONS
AbstractIn this study, twelve series of novel acceptor-donor organic materials containing
thiadiazolothienopyrazine linked to cyanoacrylic acid via dithiophene based
alternating donors are investigated. The geometries, electronic absorption and
emission spectra of these dyes are studied by Density Functional Theory (DFT)
and Time-Dependent Density Functional Theory (TD/DFT) calculations. The
calculated geometries indicate that these molecules are all coplanar. The
obtained results reveal that the electronic excitations to the lowest singlet
excited state of the studied models are dominated by the HOMO to LUMO+1
electron transition. Molecular orbital analyses reveal the characteristics of the
highest occupied molecular orbitals and lowest unoccupied molecular orbitals.
The HOMO–LUMO gaps of the ten molecules are calculated.
On the basis of these results, the correlation structure-properties is better
understood. Furthermore, the Thiadiazolothienopyrazine-based composite
seems to be a good active layer in bulk heterojunction solar cells.