ORGN 51 |
| Novel series of pi-conjugated dendritic oligofluorenes and oligothiophenes bearing efficient hole-transporting diarylamine-substituted or triarylamine-substituted carbazole-based dendritic wedge(s) with intrinsic redox gradients have been designed and synthesized using copper-catalyzed Buchwald's amination and/or Suzuki's cross-coupling as key step(s). These novel dendrimers exhibiting good energy transfer efficiencies (66-82%), very high thermal (> 540°C) and electrochemical stabilities with HOMO level of 5.2 eV can be used as charges transport enhanced molecular materials for energy transfer, photovoltaic cell and organic light-emitting diodes. Bulk heterojunction solar cells using the blend films of these dendritic oligothiophenes and PCBM as the active layer have been fabricated and investigated. The as-fabricated devices have shown enhanced performance with increasing the oligothiophene conjugation length. Due to the formation of order structures of the dendritic bithiophene after annealing, the power conversion efficiencies of this dendritic bithiophene-based device enhanced the most among the series. The detailed synthesis and structure-functional property relationships of these dendritic oligomers will be presented. |
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Materials, Devices, and Switches
8:00 AM-12:00 PM, Sunday, 10 September 2006 Moscone Center -- Room 132, Oral
Division of Organic Chemistry |