基于咔唑结构的共轭聚合物太阳能电池材料的合成及表征

Synthesis and Characterization of Carbazole Based Conjugated Polymer for Organic Photovoltaics

通过Sukuzi偶联反应,分别以3种烷基(正辛基、异辛基和十二烷基)咔唑为给体单元,4,7-二(5-溴-3-己基噻吩-2-基)-5,6-二氟-[2,1,3]苯并噻二唑为受体单元,合成了一系列共轭聚合物,并研究了不同烷基链对聚合物光吸收性能和电化学能级的影响.结果表明:相比于支化的异辛基和较长碳链的十二烷基取代的聚合物,正辛基取代的聚合物有更广的吸收范围和较窄的光学带隙,通过XRD可知π-π堆积的间距为4.13?;通过理论计算,其开路电压(VOC)可达1.15 V,更适合用作聚合物太阳能电池材料.

A series of conjugated polymers are synthesized successfully from donor unit with three kinds of alkyls（-octyl,-isooctyl,-dodecyl） carbazole and acceptor unit based on 4,7-bis（5-bromo-3-hexylthiophen-2-yl）-5,6-difluoro-[2,1,3]benzothiadiazole via Suzuki coupling reaction. The influence of optical absorption properties and electrochemical energy levels from different kinds of alkyl chains is investigated. Compared with the copolymers of branching isooctyl chain and dodecyl possessing longer carbon chains, the copolymer replaced with octyl exhibits a wider absorption region and narrower optical band gap. Besides, the spacing of π-π stacking is found to be 4.13 ？ via XRD spectra, open circuit voltage calculated by the theoretical formula reaches 1.15 V, which proves to be the suitable material for manufacturing the polymer solar cells.