双烷硫基侧链二维共轭聚合物给体材料的合成及其性能研究

发布时间：2018-04-13 14:31

本文选题：烷硫基侧链 + 苯并二噻吩　；参考：《南京理工大学》2017年硕士论文

【摘要】：近年来,聚合物太阳能电池的能量转换效率(PCEs)已经突破11%,展现出了强大的应用前景。聚合物的侧链工程可以有效调控其光伏性能,引入不同的烷基链长度或构型对聚合物材料的物化性质、与受体材料共混形貌等有着重大的影响。本论文中,通过在电子供体单元上引入不同的烷硫基链,成功合成了 7个D-A型共轭聚合物,并对其热稳定性,光学性质,电化学性质,结晶性质和光伏性能进行了系统性地研究。(1)为了研究烷硫基侧链对聚合物的性能影响,我们先合成了一系列具有不同长度的烷硫基侧链二维苯并二噻吩(BDTT-DS)供体单元,将其与电子受体单元4,7-双(5-溴-2-噻吩基)-5,6-二氟苯并[c][1,2,5]噻二唑(BTff)交替共聚得到四个具有较窄带隙的共轭聚合物 PBDTT-DS1-BTff、PBDTT-DS2-BTff、PBDTT-DS3-BTff和 PBDTT-DS4-BTff。通过研究发现,四个聚合物表现出不同的最大光吸收波长,表明它们具有不同的聚集行为,并且两个烷硫基链的引入,使得聚合物具有较低的HOMO能级(-5.50 eV),致使基于它们的器件有较高的开路电压(VOC);结果表明合适的烷硫基侧链有益于聚合物的光伏性能的提高,在本章中,基于聚合物BDTT-DS2-BTff的器件效率最优,其能量转换效率(PCE)为5.82%,其中开路电压(VOC)、短路电流密度(Jsc)和填充因子(FF)分别为0.92 V、11.06 mA/cm~2和57.2%。(2)以4,7-双溴-2-(2-乙基己基)-5,6-二氟苯并[d][1,2,3]三氮唑(FBTz)为电子受体单元,与含有不同烷硫基侧链的苯并[1,2-b:4,5-b']二噻吩供体单元交替聚合,得到聚合物 PBDTT-DS2-FBTz、PBDTT-DS4-FBTz 和 PBDTTs-FBTz。研究发现,这种共聚物具有较宽的光学带隙(～1.90 eV),且表现出良好的溶解性和结晶性能。不经过任何器件优化,基于该三个聚合物制备的电池器件均具有较高的开路电压(1.00V),且基于聚合物PBDTTs-FBTz的器件效率最优,其PCE为2.43%,其中VOC为1.01 V,JSC为 6.40 mA/cm~2,FF 为 38.0%。
[Abstract]:In recent years, the energy conversion efficiency of polymer solar cells (PCEs) has broken through 11, showing a strong application prospects.The side chain engineering of polymer can effectively control its photovoltaic performance. The introduction of different alkyl chain length or configuration has great influence on the physical and chemical properties of polymer materials and the morphology of polymer blends with acceptor materials.In this paper, seven D-A conjugated polymers have been successfully synthesized by introducing different alkanthiyl chains into the electron donor unit, and their thermal stability, optical properties and electrochemical properties have been investigated.In order to study the effect of alkanesulfide side chains on the properties of polymers, a series of 2-D benzodithiophene BDTT-DSs with different lengths were synthesized.It is found that the four polymers exhibit different maximum light absorption wavelengths, indicating that they exhibit different aggregation behaviors and the introduction of two alkyl thio chains.The polymer has a lower HOMO energy level of -5.50 EV, resulting in a higher open circuit voltage of the devices based on them. The results show that the appropriate alkane sulfur side chain is beneficial to the improvement of the photovoltaic performance of the polymer, and in this chapter,The device efficiency is optimal based on polymer BDTT-DS2-BTff.It is found that the copolymer has a wide optical band gap of 1.90 EV, and shows good solubility and crystallinity.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O631.3;TM914.4

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