Effects of bridging atom in donor units and nature of acceptor groups on physical and photovoltaic properties of A-π-D-π-A oligomers
| Autor: | Jie Min, Yuriy N. Luponosov, Linda Grodd, Evgeniya A. Svidchenko, Christoph J. Brabec, Svetlana M. Peregudova, Souren Grigorian, Sergei A. Ponomarenko, Petr V. Dmitryakov, Sergei N. Chvalun, Dmitry A. Khanin |
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| Rok vydání: | 2018 |
| Předmět: |
Thermogravimetric analysis
Materials science Absorption spectroscopy Organic solar cell 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Acceptor 0104 chemical sciences Electronic Optical and Magnetic Materials Biomaterials Differential scanning calorimetry Materials Chemistry Molecule Physical chemistry Electrical and Electronic Engineering Cyclic voltammetry 0210 nano-technology HOMO/LUMO |
| Zdroj: | Organic Electronics. 55:42-49 |
| ISSN: | 1566-1199 |
| Popis: | The synthesis of a series of novel A-π-D-π-A oligomers bearing either electron-donating dithieno[3,2-b:2′,3′-d]silole (DTS) or dithieno[3,2-b:2′,3′-d]pyrrole (DTP) units linked through a bithiophene π-bridge with the electron-withdrawing methyldicyanovinyl (DCV) or N-ethylrhodanine (Rh) groups is described. In order to evaluate the effects of different donor-acceptor combinations on various physical properties of the oligomers they are comprehensively studied by UV–Vis spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and cyclic voltammetry (CV). Replacing the DTS by DTP as well as the DCV by Rh leads to increasing of HOMO energy levels and slight decreasing of LUMO energy levels, respectively. The DTP-based oligomers have a red shift in absorption spectra and an increased solubility as compared to the DTS-based analogs. Replacing the acceptor DCV unit by Rh also results in significantly higher solubility, but the Rh-based oligomers exhibit weaker intermolecular interactions, poorer optical absorption of sun light as well as lower charge carrier mobility in blends. Altogether, the structural improvement of the DTS-DCV and DTP-DCV blends upon annealing correlates well with the observed photovoltaic performances in organic solar cells. These results give more insight how to fine-tune and predict physical properties and photovoltaic performance of small A-π-D-π-A molecules having different donor-acceptor combinations in their chemical structures and thus providing a molecular design guideline for the next generation of high-performance photovoltaic materials. |
| Databáze: | OpenAIRE |
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