Organic BODIPY Based Gels: Optical, Electrochemical and Self-Assembly Properties.

Two novel BODIPY dyes, BOC3 and BC12, were synthesized with variable alkyl chains at terminal amide functional units. BC12, featuring a longer alkyl chain (-CH), formed a gel compared to BOC3, which has a shorter alkyl chain (< C->CHOCH), due to supra molecular self-assembly in film. Both dyes exhibited absorption peaks around 530 nm in the visible region, with a red shift of about 30 nm in the film state, essential for organic electronic applications.

An Organic Dyad Composed of Diathiafulvalene-Functionalized Diketopyrrolopyrrole-Fullerene for Single-Component High-Efficiency Organic Solar Cells.

A new low-band gap dyad DPP-Ful, which consists of covalently linked dithiafulvalene-functionalized diketopyrrolopyrrole as donor and fullerene (C60 ) as the acceptor, has been designed and synthesized. Organic solar cells were successfully constructed using the DPP-Ful dyad as an active layer. This system has a record power-conversion efficiency (PCE) of 2.

Highly Directional 1D Supramolecular Assembly of New Diketopyrrolopyrrole-Based Gel for Organic Solar Cell Applications.

A new thermoreversible organogel based on diketopyrrolopyrrole dye (DPP-NCO) is reported for the first time and evolved as a new building block for the fabrication of 1D supramolecular assembly. AFM analysis illustrated that its gel state is composed of different sized 1D rods. DPP-NCO gel used as an additive in organic solar cells yields high efficiency of 7.

Near-infrared unsymmetrical blue and green squaraine sensitizers.

Two novel panchromatic asymmetrical squaraine sensitizers (SPSQ1 and SPSQ2) have been synthesized, characterized and effectively used for TiO2-based dye sensitized solar cells. In a solution, both dyes display a highly intense near-IR absorption (SPSQ1; 651 nm and SPSQ2; 692 nm), the red shifted absorption of SPSQ2 was attributed to the incorporation of the auxiliary acceptor dicyanovinyl unit on the squaraine moiety. Interestingly, the dicyanovinyl unit lowered the LUMO level of SPSQ2, which decreased the band gap and red shifted the absorption when compared to SPSQ1.

NIR absorbing D-π-A-π-D structured diketopyrrolopyrrole-dithiafulvalene based small molecule for solution processed organic solar cells.

A new low band gap small molecule with a D-π-A-π-D molecular structure composed of a dithiafulvalene (DTF) donor and a diketopyrrolopyrrole (DPP) acceptor was synthesized and tested for organic solar cells. Using the small molecule as an electron donor, and PC71BM as an acceptor a high power conversion efficiency (PCE) of 4.3% was achieved.

Organic dyes containing carbazole as donor and π-linker: optical, electrochemical, and photovoltaic properties.

A series of new metal free organic dyes containing carbazole as donor and π-linker have been synthesized and characterized as effective sensitizers for dye sensitized solar cells (DSSCs). The carbazole functionalized at C-2 and C-7 served as electron-rich bridge. The donor property of the carbazole is substantially enhanced on introduction of tert-butyl groups at C-3 and C-6 positions and the oxidation propensity of the dyes increased on insertion of thiophene unit in the conjugation pathway.

Solution processable indoloquinoxaline derivatives containing bulky polyaromatic hydrocarbons: synthesis, optical spectra, and electroluminescence.

New hybrid materials featuring the dipolar fragment 6H-indolo[2,3-b]quinoxaline attached to the bulkier polyaromatic hydrocarbons such as fluoranthene, triphenylene, or polyphenylated benzene have been synthesized by a two-step procedure involving Sonogashira and Diels-Alder reactions. They were characterized by absorption, emission, electrochemical, thermal, and theoretical investigations. The electronic properties of the compounds were dominated by the 6H-indolo[2,3-b]quinoxaline chromophore, and the incorporation of polyaromatic hydrocarbons reduces the chances of nonradiative deactivation processes associated with the excited state and improves the emission properties.