NEW ORGANIC MATERIALS BASED ON THIADIAZOLOTHIENOPYRAZINEâ€“DITHIOPHENE FOR PHOTOVOLTAIC APPLICATIONS
AbstractIn this study, twelve series of novel acceptor-donor organic materials containing
thiadiazolothienopyrazineÂ linkedÂ toÂ cyanoacrylicÂ acidÂ viaÂ dithiopheneÂ based
alternating donors are investigated. The geometries, electronic absorption and
emission spectra of these dyes are studied by Density Functional Theory (DFT)
andÂ Time-DependentÂ DensityÂ FunctionalÂ TheoryÂ (TD/DFT)Â calculations.Â The
calculatedÂ geometriesÂ indicateÂ thatÂ theseÂ moleculesÂ areÂ allÂ coplanar.Â The
obtainedÂ resultsÂ revealÂ thatÂ theÂ electronicÂ excitationsÂ toÂ theÂ lowestÂ singlet
excitedÂ stateÂ ofÂ theÂ studiedÂ modelsÂ areÂ dominatedÂ byÂ theÂ HOMOÂ toÂ LUMO+1
electron transition. Molecular orbital analyses reveal theÂ Â Â Â characteristics of theÂ Â Â Â Â Â Â
highestÂ Â occupied molecular orbitals and lowest unoccupied molecular orbitals.
The HOMOâ€“LUMO gaps of the ten molecules are calculated. Â
OnÂ theÂ basisÂ ofÂ theseÂ results,Â theÂ correlationÂ structure-propertiesÂ isÂ better
understood.Â Furthermore,Â theÂ Thiadiazolothienopyrazine-basedÂ composite
seems to be a good active layer in bulk heterojunction solar cells.