Synthesis and optical properties of photovoltaic materials based on the ambipolar dithienonaphthothiadiazole unit
Synthesis and optical properties of photovoltaic materials based on the ambipolar dithienonaphthothiadiazole unit
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DOI：
10.1039/c4ta05101g
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发表时间：
2015-02
影响因子：
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通讯作者：
Tatsuaki Nakanishi;Y. Shirai;Liyuan Han
中科院分区：
文献类型：
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作者：
Tatsuaki Nakanishi;Y. Shirai;Liyuan Han
二噻吩并[3′2′：5，6; 2′′，3 ′′：7，8]萘并[2，3-c][1，2，5]噻二唑（DTNT）被设计用于控制光伏材料聚合物的能带能量。电化学分析表明，DTNT作为电子供体和电子受体，揭示了双极性的DTNT单元的性质。DTNT分别与2，2 ′-联噻吩（BTh）和3，6-二（2-噻吩基）吡咯并[3，4-c]吡咯-1，4-二酮（DPP）进行直接芳基化聚合，得到了4种不同共聚单元和侧链的聚合物。在PDTNT-BTh系列中，在比强吸收带更长的波长处观察到肩吸收带。PDTNT-DPP系列显示出小于1.4 eV的窄带隙和−5.43 eV的低HOMO能量。含有具有2-乙基己基的PDTNT-BTh聚合物和[6，6]-苯基-C71-丁酸甲酯（PC 71 BM）作为活性层的有机光伏电池在所研究的化合物中提供了最佳性能，JSC为6.98 mA cm-3，VOC为0.758 V，FF为0.52，PCE为2.76%。
Dithieno[3′2′:5,6;2′′,3′′:7,8]naphtho[2,3-c][1,2,5]thiadiazole (DTNT) was designed to control the band energies of the polymers for photovoltaic materials. Electrochemical analysis showed that DTNT acts as both an electron donor and an electron acceptor, revealing the ambipolar nature of the DTNT unit. The direct arylation polymerization of DTNT with 2,2′-bithiophene (BTh) and 3,6-bis(2-thienyl)pyrrolo[3,4-c]pyrrole-1,4-dione (DPP) afforded four polymers that differed in either the unit of copolymerization or the chosen side chains. In the PDTNT-BTh series, a shoulder absorption band was observed at a longer wavelength than the intense absorption band. The PDTNT-DPP series exhibited a narrow band gap of less than 1.4 eV and a low HOMO energy of −5.43 eV. An organic photovoltaic cell that contained a PDTNT-BTh polymer with 2-ethylhexyl groups and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as an active layer afforded the best performance among the studied compounds, with a JSC of 6.98 mA cm−3, a VOC of 0.758 V, a FF of 0.52, and a PCE of 2.76%.