Ethyladamantyl solubilization side groups were found to induce π−π interactions between the conjugated cores in soluble diketopyrrolopyrrole derivatives.

Flavins are known to be extremely versatile, thus enabling routes to innumerable modifications in order to obtain desired properties. Thus, in the present paper, the group of bio-inspired conjugated materials based on the alloxazine core is synthetized using two efficient novel synthetic approaches providing relatively high reaction yields. The comprehensive characterization of the materials, in order to evaluate the properties and application potential, has shown that the modification of the initial alloxazine core with aromatic substituents allows fine tuning of the optical bandgap, position of electronic orbitals, absorption and emission properties. Interestingly, the compounds possess multichromophoric behavior, which is assumed to be the results of an intramolecular proton transfer.

In this work, we investigated diketopyrrolopyrrole (DPP) derivatives as potential donor materials for fullerene:DPP solar cells. The derivatives 3,6-bis­(5-(benzofuran-2-yl)­thiophene-2-yl)-2,5-bis­(2-ethylhexyl)­pyrrolo­[3,4-c]­pyrrole-1,4-dione (DPP­(TBFu)2) and 3,6-bis­(5-(benzothiophene-2-yl)­thiophene-2-yl)-2,5-bis­(2-ethylhexyl)­pyrrolo­[3,4-c]­pyrrole-1,4-dione (DPP­(TBTh)2) were modified by introducing a nitrogen atom into the terminal moiety of the molecule. Our quantum-chemical calculations predicted that this modification would increase the rigidity of the molecular structure and increase the ionization potential relative to the original DPP derivatives. The higher ionization potential primarily supports an enhancement in the open circuit voltage, and a more rigid molecular structure will contribute to reduced nonradiative losses. We experimentally verified the fullerene:DPP solar cell concept based on the coincidence of a smaller driving force for charge separation at the donor/acceptor interface and the crystallinity of the studied DPP derivatives for preparing effective photovoltaic devices. The reduction of the driving force for charge separation could be overcome by more structured/packed donor DPP materials; the delocalization of electrons and holes in such structured materials improves charge separation in OPV devices. Using wide range of experimental methods, we determined the parameters of the studied DPP materials with PC70BM in thin films. This work contributes to practical applications by verifying the concept of this organic solar cell design.

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The present paper demonstrates the possibility of replacing indium tin oxide (ITO) with heavily boron-doped diamond (BDD). Plasma Enhanced Chemically Vapor Deposited BDDs of various thicknesses were prepared containing various boron concentrations in a gas phase. The dependence of the above-mentioned parameters on the optical and electrical properties of each BDD was studied in order to achieve optimal conditions for the effective application of diamond electrodes in organic electronics as a replacement for ITO. Bulk-heterojunction polymer-fullerene organic solar cells were fabricated to test the potency of BDD application in photovoltaic devices. The obtained results demonstrated the possibility of the aforementioned application. Even though the efficiency of BDDbased devices is lower compared to those using regular ITO-based architecture, the relevant issues were explained.