850881-10-6Relevant articles and documents
'Donor-free' oligo(3-hexylthiophene) dyes for efficient dye-sensitized solar cells
Hu, Yue,Ivaturi, Aruna,Planells, Miquel,Boldrini, Chiara L.,Biroli, Alessio Orbelli,Robertson, Neil
, p. 2509 - 2516 (2016)
The common trend in designing dyes for use in DSSCs with iodide-based electrolyte is based on a donor-π spacer-acceptor (D-π-A) architecture. Here, we report two 'donor-free' cyanoacrylic end-functionalized oligo(3-hexylthiophene) dyes (5T and 6T). Despite having no donor group, both dyes show reversible first oxidation process. Both 5T and 6T have n-hexyl alkyl chains to retard aggregation at different positions as well as different numbers of thiophene moieties. However, the dyes showed similar absorption properties and redox potentials. The DSSCs based on these dyes give power conversion efficiencies of more than 7%, although a significant difference in the VOC and FF has been observed. Using electrochemical impedance spectroscopy, this is attributed to the presence of more trap states when 6T attaches to TiO2 and modifies the surface, mainly affecting the fill factor. Overall, these dyes introduce a new and effective design concept for liquid-electrolyte DSSC sensitisers.
Supramolecular engineering of oligothiophene nanorods without insulators: Hierarchical association of rosettes and photovoltaic properties
Yagai, Shiki,Suzuki, Mika,Lin, Xu,Gushiken, Marina,Noguchi, Takuya,Karatsu, Takashi,Kitamura, Akihide,Saeki, Akinori,Seki, Shu,Kikkawa, Yoshihiro,Tani, Yuki,Nakayama, Ken-Ichi
, p. 16128 - 16137 (2015/02/19)
Supramolecular rosettes of oligothiophenes that do not bear long aliphatic tails have been designed as semiconducting nanomaterials for solution-processable bulk het-erojunction solar cells. The rosettes consist of six barbiturat-ed thienyl[oligo(hexylthiophene)] units (Bar-T-hTn; n = 3,4,5) aggregated by multiple hydrogen bonds, which have been directly visualized by scanning tunneling microscopy (STM) at a solid-liquid interface. 1H NMR spectroscopy in [D8]toluene showed that Bar-T-hTn exists as a mixture of monomers and small hydrogen-bonded aggregates. Hierarchical organization of the hydrogen-bonded aggregates took place through π - π stacking interactions upon casting their toluene solutions, resulting in the growth of highly ordered nanorods whose widths are consistent with the diameters of the rosettes. The nanorods could be generated in the presence of soluble fullerene derivatives via solution casting or the annealing of the resulting thin films. The solar cells fabricated based on these bulk heterojunction films showed power conversion efficiencies of 1-3%, which are far higher than those of the non-hydrogen-bonded reference oligothiophene and the derivative that possesses long aliphatic tails.
Dye-functionalized head-to-tail coupled oligo(3-hexylthiophenes) - Perylene-oligothiophene dyads for photovoltaic applications
Cremer, Jens,Mena-Osteritz, Elena,Pschierer, Neil G.,Muellen, Klaus,Baeuerle, Peter
, p. 985 - 995 (2007/10/03)
A series of novel donor-acceptor systems, consisting of head-to-tail coupled oligo(3-hexylthiophene)s covalently linked to perylenemonoimide, is described. These hybrid molecules, which differ by the length of the oligothiophene units from a monothiophene up to an octathiophene, were created via effective palladium-catalyzed Negishi and Suzuki cross-coupling reactions in good to excellent yields. The optical and electrochemical properties of these compounds were determined and based on this series structure-property relationships have been established which give vital information for the fabrication of photovoltaic devices. Because the synthesized perylenyl-oligothiophenes distinguish themselves by a high absorption between 300 and 550 nm and an almost complete fluorescence quenching of the perylene acceptor, they meet the requirements for organic solar cells. The Royal Society of Chemistry 2005.
