Acceptor-donor-acceptor oligomers containing dithieno[3,2-b:2',3'-d]pyrrole and thieno[2,3-c]pyrrole-4,6-dione units for solution-processed organic solar cells.

New acceptor-donor-acceptor (A-D-A) oligomers (1 and 2) containing a central dithieno[3,2-b:2',3'-d]pyrrole unit and end-capping thieno[2,3-c]pyrrole-4,6-dione groups have been synthesized and characterized. Bulk heterojunction solar cells were prepared together with PC61BM and PC71BM, and the best results were obtained for the latter acceptor using 1,8-diiodooctane as an additive. Photovoltaic devices containing these oligomers achieved high external quantum efficiencies up to 50%.

Optimization of solution-processed oligothiophene:fullerene based organic solar cells by using solvent additives.

The optimization of solution-processed organic bulk-heterojunction solar cells with the acceptor-substituted quinquethiophene DCV5T-Bu 4 as donor in conjunction with PC61BM as acceptor is described. Power conversion efficiencies up to 3.0% and external quantum efficiencies up to 40% were obtained through the use of 1-chloronaphthalene as solvent additive in the fabrication of the photovoltaic devices.

Dithienopyrrole-based oligothiophenes for solution-processed organic solar cells.

Isomeric dicyanovinylene-terminated oligothiophenes 1 and 2 comprising a central dithienopyrrole (DTP) unit have been developed for solution-processed small molecule organic solar cells (SMOSCs) giving the highest power conversion efficiency of 4.8% for DTP-based oligomeric materials.

2,2':3',2''-Terthiophene-based all-thiophene dendrons and dendrimers: synthesis, structural characterization, and properties.

The synthesis of generational dendritic oligothiophenes (DOTs) has been successfully achieved by a divergent/convergent approach that involves halogenation, boronation, and palladium-catalyzed Suzuki coupling reactions. The key point in the presented synthetic approach is the use of trimethylsilyl (TMS) protecting groups, which allow for the core-lithiation and subsequent boronation of the dendrons and for the peripheral ipso-substitution with iodine monochloride or N-bromosuccimide. In addition, the TMS protecting groups can be completely removed by using tetrabutylammonium fluoride, thus yielding only-thiophene-based dendrons and dendrimers.

Correlation of π-conjugated oligomer structure with film morphology and organic solar cell performance.

The novel methyl-substituted dicyanovinyl-capped quinquethiophenes 1-3 led to highly efficient organic solar cells with power conversion efficiencies of 4.8-6.9%.