Synthesis and determination of fluorescence properties of new, slouble diketopyrrolopyrrole type photosensitizers

In this thesis, synthesis and structural characterization of new type dye molecules targeted to reach high solar energy-power conversion efficiency for bulk heterojunction solar cells (BHJCs) have been studied. In our studies, DPP1-coded diketopyrrolopyrrole molecule as starting compound was synthesized using 4-bromobenzonitrile and diethylsuccinate reagents. In order to increase the solubility of this dye, DPP2a and DPP2b derivatives substituted with ethylhexyl and di-tert-butyl-dicarbonate groups were synthesized. Then, DPP3a- and DPP3b-coded molecules were synthesized via Suzuki coupling reaction with indole group. Finally, DPP4a- and DPP4b-coded molecules were synthesized again via Suzuki reaction with indole group carrying di-tert-butyl-dicarbonate structure as solubilizing subunit. UV-visible absorption, fluorescence emission and fluorescence decay kinetic measurements of these dyes were studied. HOMO and LUMO energy band levels of these compounds were calculated using cyclic voltammetry. Then, the potential usage of the final products in bulk heterojunction solar cells were discussed.