標題: | Evolving molecular architectures of donor-acceptor conjugated polymers for photovoltaic applications: from one-dimensional to branched to two-dimensional structures |
作者: | Su, Yu-Wei Lin, Yu-Che Wei, Kung-Hwa 材料科學與工程學系 Department of Materials Science and Engineering |
公開日期: | 14-十二月-2017 |
摘要: | Over the last ten years, the molecular architectures of p-type donor-acceptor (D-A) conjugated polymers designed for bulk heterojunction (BHJ) photovoltaics, when mixed with fullerenes or n-type polymers, have progressed substantially from one-dimensional (1-D) to branched to two-dimensional (2-D) D-A conjugated structures. In the 1-D structures, alternating D and A units allow internal charge transfer along the conjugated backbone and increase the effective resonance length, as a result of facilitated pi-electron delocalization. Upon progressing from 1-D structures to branched D-A conjugated polymers (comprising repeating donor units in the main chain with electron-withdrawing side chain units) to 2-D conjugated polymers (having D-A repeating units on their backbones as well as perpendicular electron-donating groups on their D units), the solubility, effective conjugation length, and photophysical and BHJ photovoltaic properties have all been altered dramatically. The ideal p-type 2-D conjugated D-A polymer for use in BHJ photovoltaic devices should possess a low band gap (to broaden the absorption range), excellent packing characteristics (particularly along the out-of-plane direction, ensuring good carrier transport), and suitable energy levels for efficient electron transfer (to fullerene moieties or n-type polymers). In this review, we discuss the effects of the structural characteristics and optical properties of these conjugated polymers as well as their packing characteristics on the device performances. |
URI: | http://dx.doi.org/10.1039/c7ta07228g http://hdl.handle.net/11536/144135 |
ISSN: | 2050-7488 |
DOI: | 10.1039/c7ta07228g |
期刊: | JOURNAL OF MATERIALS CHEMISTRY A |
Volume: | 5 |
起始頁: | 24051 |
結束頁: | 24075 |
顯示於類別: | 期刊論文 |