Small D-π-A systems with o-phenylene-bridged accepting units as active materials for organic photovoltaics.

Donor-acceptor (D-π-A) systems that combine triarylamine donor blocks and dicyanovinyl (DCV) acceptor groups have been synthesized. Starting from the triphenylamine (TPA)-thiophene-DCV compound (1) as a reference system, various synthetic approaches have been developed for controlling the light-harvesting properties and energy levels of the frontier orbitals in this molecule. Thus, the introduction of methoxy groups onto TPA, the replacement of one phenyl ring of TPA by a thiophene ring, or the extension of the π-conjugating spacer group lead to the modulation of the HOMO level.

Triphenylamine/tetracyanobutadiene-based D-A-D π-conjugated systems as molecular donors for organic solar cells.

Thiophene-based D-A-D π-conjugated systems containing triphenylamine end groups connected to a 1,1,4,4-tetracyanobuta-1,3-diene acceptor by oligothiophene chains of variable length have been synthesized. These compounds show interesting light-harvesting properties and low-lying HOMO levels. Preliminary results on bilayer heterojunction solar cells with C(60) as acceptor show power conversion efficiency higher than 1.

A tailored hybrid BODIPY-oligothiophene donor for molecular bulk heterojunction solar cells with improved performances.

Fixation of a 5-hexyl-2,2'-bithienyl unit on a conjugated BODIPY donor increases the conversion efficiency of the resulting molecular bulk heterojunction solar cells from 1.30 to 2.20%.

BODIPY derivatives as donor materials for bulk heterojunction solar cells.

BODIPY derivatives have been used as donor in solution-processed bulk heterojunction solar cells using PCBM as acceptor. A power conversion efficiency of 1.34% has been obtained under simulated solar irradiation.