Investigation of Optical and Electrical Properties to Selenophene and Thiophene as π-bridge in Organic Photovoltaic Polymers
| Autor: | Yuan-Cheng Hu, 胡元正 |
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| Rok vydání: | 2015 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 103 In this study, we report two conjugated copolymers, combined with indacenodithiophene- (IDT) and fluorinated quinoxaline- (FQ) based monomers, while using thiophene and selenophene as π-bridge in both, yielding pIDTTFQ and pIDTSFQ, respectively. In an aim to apply them into polymer photovoltaics and achieve better power conversion efficiencies (PCEs), alternating variant π-space to harness the photochemical properties of conjugated copolymers has been one of the strategies in modifying present copolymer combinations. Theoretical calculations reveal that the usage of selenophene reliefs the intramolecular repulsion and the corresponding twist, with the decrease of dihedral angle. Compared with pIDTTFQ, the absorption edge of pIDTSFQ in solid state is extended from 685nm to 742nm, while the EHOMO was increased from -5.37eV to -5.31eV. Considering the decreased Voc and the enhanced Jsc, the optimized pIDTTFQ- and pIDTSFQ-based devices achieve PCE values of 2.0±0.1% and 2.6±0.5%, respectively. However, the two polymers exhibit similar devices performance but much different absorption ranges, which signifies the potential of choosing selenophene as π-bridge to achieve better device performance. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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