Indolo[3,2-b]carbazole-based alternating donor–acceptor copolymers: synthesis, properties and photovoltaic application
作者:Erjun Zhou、Shimpei Yamakawa、Yue Zhang、Keisuke Tajima、Chunhe Yang、Kazuhito Hashimoto
DOI:10.1039/b912258c
日期:——
Two new donorâacceptor (DâA) type copolymers, poly5,11-di(1-decylundecyl)indolo[3,2-b]carbazole-3,9-diyl-alt-4,7-dithien-2-yl-2,1,3-benzothiadiazole-5â²,5â³-diyl} (PIC-DTBT) and poly5,11-di(1-decylundecyl)indolo[3,2-b]carbazole-3,9-diyl-alt-4,7-di(2,2â²-bithien-5-yl)-2,1,3-benzothiadiazole-5â²,5â³-diyl} (PIC-DT2BT) were synthesized. The polymers have an alternating structure consisting of a large-size fused aromatic ring, indolo[3,2-b]carbazole (IC), as the donor segment and 4,7-dithien-2-yl-2,1,3-benzothiadiazole (DTBT) or 4,7-di(2,2â²-bithien-5-yl)-2,1,3-benzothiadiazole (DT2BT) as the acceptor segment. The absorption spectra and the electrochemical properties of PIC-DTBT and PIC-DT2BT indicate that these copolymers have suitable energy levels for photovoltaic application. Polymer photovoltaic devices based on blends of the copolymers and [6,6]-phenyl C61 butyric acid methyl ester (PCBM) have a high open-circuit voltage (>0.9 V) under the illumination of AM 1.5 (100 mW cmâ2). The higher power conversion efficiency (PCE) of PIC-DT2BT (2.07%) compared to that of PIC-DTBT (1.47%) suggests that DT2BT could be a promising building block for the efficient DâA type copolymers if the low solubility is overcome by the molecular design of the donor segment.
合成了两种新的给体-受体型共聚物,聚5,11-二(1-癸基
十一烷基)
吲哚并[3,2-b]咔唑-3,9-二基-alt-4,7-二
噻吩-2-基-
2,1,3-苯并噻二唑-5',5''-二基}(
PIC-DTBT)和聚5,11-二(1-癸基
十一烷基)
吲哚并[3,2-b]咔唑-3,9-二基-alt-4,7-二(2,2'-联
噻吩-5-基)-
2,1,3-苯并噻二唑-5',5''-二基}(
PIC-DT2BT)。这些聚合物具有交替结构,其中大尺寸的融合芳香环
吲哚并[3,2-b]咔唑(IC)作为给体部分,4,7-二
噻吩-2-基-
2,1,3-苯并噻二唑(DTBT)或4,7-二(2,2'-联
噻吩-5-基)-
2,1,3-苯并噻二唑(DT2BT)作为受体部分。
PIC-DTBT和
PIC-DT2BT的吸收光谱和电
化学性质表明,这些共聚物具有适合光伏应用的能级。基于这些共聚物和[6,6]-苯基C61
丁酸甲酯(PCBM)混合物的聚合物光伏器件在
AM 1.5(100 mW cm⁻²)照射下具有较高的开路电压(>0.9 V)。
PIC-DT2BT(2.07%)相对于
PIC-DTBT(1.47%)更高的功率转换效率(PCE)表明,如果通过给体部分的分子设计克服其低溶解度,DT2BT可能是一种有前途的高效给体-受体型共聚物的构建单元。