Fused Dithienogermolodithiophene Low Band Gap Polymers for High-Performance Organic Solar Cells without Processing Additives
作者:Hongliang Zhong、Zhe Li、Florent Deledalle、Elisa Collado Fregoso、Munazza Shahid、Zhuping Fei、Christian B. Nielsen、Nir Yaacobi-Gross、Stephan Rossbauer、Thomas D. Anthopoulos、James R. Durrant、Martin Heeney
DOI:10.1021/ja311700u
日期:2013.2.13
We report the synthesis of a novel ladder-type fused ring donor, dithienogermolodithiophene, in which two thieno[3,2-b]thiophene units are held coplanar by a bridging dialkyl germanium. Polymerization of this extended monomer with N-octylthienopyrrolodione by Stille polycondensation afforded a polymer, pDTTG-TPD, with an optical band gap of 1.75 eV combined with a high ionization potential. Bulk heterojunction solar cells based upon pDTTG-TPD:PC71BM blends afforded efficiencies up to 7.2% without the need for thermal annealing or processing additives.
Regiochemical Effects of Sulfur Oxidation on the Electronic and Solid-State Properties of Planarized Oligothiophenes Containing Thieno[3,2-<i>b</i>]thiophene Units
作者:Lidaris San Miguel、Adam J. Matzger
DOI:10.1021/jo801619q
日期:2008.10.17
The effect of position and degree of sulfur oxidation on the fundamental properties of a series of planarized thieno[3,2-b]thiophene S,S-dioxides derivatives was studied. The optical data reveal a red shift in the longest wavelength of absorption relative to the nonoxidized analogues that is indicative of a reduced HOMO-LUMO gap. The position of oxidation rather than the extent of oxidation is the most critical factor in controlling electronic properties. Single-crystal analysis reveals that some of the oligothiophene S,S-dioxides studied present pi-pi interactions which are completely absent in the nonoxidized analogue.