基于苯并二噻吩的共轭聚合物的合成及其在太阳能电池中的应用

发布时间：2018-06-27 09:35

本文选题：聚合物太阳能电池 + 苯并二噻吩　；参考：《中国海洋大学》2015年硕士论文

【摘要】：传统的石化资源一方面面临着能源枯竭危机,另一方面在应用的同时也造成极大的环境污染。因此,人们急切需要开发和利用一些资源丰富、可再生利用的清洁能源,以满足日益增长的能源需求。在各种可再生能源中,太阳能属于取之不尽、用之不竭的可再生绿色能源。太阳能具有不受地域限制、没有噪音、无污染、利用成本较低等优势,因此是人类获取清洁能源的最佳途径之一,而高效、方便地利用太阳能的重要方式之一就是太阳能电池的推广应用。相比传统无机太阳能电池,有机太阳能电池能够采用低成本的溶液加工法制备质轻、柔性的大面积器件,而且相关材料可以轻易进行化学设计、裁剪和合成,引起了各国科学家和各大公司的浓厚兴趣,迅速形成了研究热潮。本文按照给体-受体(D-A)的设计思路,合成了一系列共轭聚合物,并对其光伏性能进行了研究。在第二章,通过Stille偶联反应,将4,8-双(5-(3,4,5-三(氧基)苯基)噻吩-2-基)苯并[1,2-b：4,5-b']二噻吩(TOBDT)与2,3-联苯-5,8-间(噻吩-2-基)喹喔啉(TQ1)或10,13-间(4-(2-乙基已基)噻吩-2-基)二苯并[a,c]吩嗪(TQ2)聚合得到了两种基于苯并二噻吩和喹喔啉的共聚物。通过增加TQ2单元中的共轭程度,其聚合物表现出了较窄的带隙(Eg),较低的HOMO能级和增强的链间的π-π相互作用。相对于TQ1,基于TQ2的聚合物太阳能电池的开路电压(Voc)、短路电流密度(Jsc)和填充因子(FF)性能参数的同时提升。基于TQ2和PC71BM的器件获得了4.24%的光电转换效率。这些结果初步表明通过增加受体单元(喹喔啉)的共轭程度,是一种提高聚合物太阳能电池性能的有效方法。在第三章,为了深入研究平面性,烷基侧链引起的空间位阻及分子量的影响以得到高效率聚合物太阳能电池,我们设计并合成了一种“平整型”聚合物PTOBDTDTffBT。通过将DTffBT单元上的烷基侧链移除,并且在BDT单元上引入了更短的辛氧基侧链,实现了分子内和分子间的空间位阻最小化。运用此空间位阻最小化策略,得到了具有高数均分子量(343.37 kg/mol),平整的共轭骨架和强聚集特性的的聚合物PTOBDTDTffBT。光学特性表明,即使在160℃下,分子间强的聚集也只能被部分破坏。理论计算提供了更为深刻的信息：聚合物骨架的扭转角非常小：噻吩-苯基桥使得辛氧基向聚合物骨架外移6.77A。以上两点都确保了分子间强的聚集特性。尽管聚合物PTOBDTDTffBT拥有高平面性和强聚集特性,但掠入射X射线衍射分析表明其薄膜为无定型。聚合物PTOBDTDTffBT表现了深达-5.46 eV的HOMO能级和1.71 eV的窄带隙。由于强聚集特性,PTOBDTDTffBT/PC71BM活性层表现出了随温度变化而变化的光伏特性：在100℃以下温度旋涂活性层时,器件效率稳定在6.6%以上；但旋涂温度升高到120到160℃间时,短路电流和填充因子下降,器件效率也逐渐下降到3.58%。从高温度下聚合物溶液的UV-vis吸收光谱和X射线光电子能谱分析可以推断,器件光伏性能随制备活性层温度变化的原因可以解释为：高温度溶液中PC71BM更容易被甩出;并且AFM和TEM观察发现高温度可能导致活性层更粗糙和形貌和更大尺寸的相分离。最终,在80℃下旋涂制备活性层时,器件效率达到了7.68%,这对于“平整型”PBDT-DFffBT聚合物来说,是一个巨大的突破。
[Abstract]:On the one hand, the traditional petrochemical resources are faced with the crisis of energy exhaustion, on the other hand, it also causes great environmental pollution at the same time. Therefore, people urgently need to develop and utilize some clean energy, which are rich in resources and renewable, in order to meet the increasing energy demand. In all kinds of renewable energy, solar energy is not the one. Solar energy is one of the best ways to obtain clean energy, which is one of the most important ways for human to get clean energy. One of the most important ways to use solar energy efficiently and conveniently is the promotion and application of solar cells. Compared with the traditional inorganic solar energy. Energy batteries, organic solar cells can use low cost solution processing method to prepare light and flexible large area devices, and the related materials can be easily designed, cut and synthesized. It has aroused the interest of scientists and companies in various countries and rapidly formed a research upsurge. This paper is based on the design of the donor receptor (D-A). A series of conjugated polymers were synthesized and their photovoltaic properties were studied. In the second chapter, 4,8- double (5- (3,4,5- three (Yang Ji) phenyl) thiophene -2- based thiophene (TOBDT) and 2,3- biphenyl -5,8- (thiophene -2- based) (TQ1) or 10,13- (3,4,5-) thiophene (thiophene thiophene) two were synthesized through the coupling reaction in the second chapter. The copolymers of benzo [a, c] phenazine (TQ2) polymerization obtained two kinds of copolymers based on benzo two thiophene and chlorozine. By increasing the degree of conjugation in the TQ2 unit, the polymer shows a narrower band gap (Eg), a lower HOMO level and an enhanced interchain pion interaction. Relative to TQ1, the open circuit voltage of a TQ2 based polymer solar cell (Voc) ) the simultaneous enhancement of the short circuit current density (Jsc) and the filling factor (FF) performance parameters. The devices based on TQ2 and PC71BM obtained 4.24% photoelectric conversion efficiency. These results preliminarily indicate that by increasing the conjugation degree of the receptor unit (q), it is an effective method to improve the performance of the polymer too solar energy battery. In the third chapter, for further research We have designed and synthesized a "flat" polymer PTOBDTDTffBT. by removing the alkyl side chain on the DTffBT unit and introducing a shorter octyl side chain on the BDT unit to realize the intramolecular and the intramolecular. The spatial steric hindrance minimization between molecules. Using this space steric minimization strategy, the optical properties of polymer PTOBDTDTffBT. with high number average molecular weight (343.37 kg/mol), a flat conjugate skeleton and strong aggregation characteristics show that even at 160 C, the intermolecular strong aggregation can only be partially destroyed. Deep information: the twist angle of the polymer skeleton is very small: the thiophene phenyl bridge makes the octyl group moving to the polymer skeleton outside 6.77A., which ensures the strong intermolecular aggregation. Although the polymer PTOBDTDTffBT has high flatness and strong aggregation properties, the grazing incidence X ray diffraction analysis shows that the film is amorphous. The substance PTOBDTDTffBT shows the HOMO level of -5.46 eV and the narrow band gap of 1.71 eV. Because of the strong aggregation characteristics, the PTOBDTDTffBT/PC71BM active layer shows the photovoltaic characteristics that vary with the temperature. The efficiency of the device is more than 6.6% when the active layer is spinning below 100 centigrade, but the spin coating temperature rises to 120 to 160 centigrade. The circuit current and filling factor decrease, and the device efficiency is gradually reduced to 3.58%. from high temperature polymer solution UV-vis absorption spectrum and X ray photoelectron spectroscopy analysis, which can be explained by the reason that the photovoltaic performance of the device changes with the temperature of the active layer can be explained as the PC71BM in high temperature solution is easier to be thrown out; and the AFM and TEM view It was found that high temperature could lead to more roughness of the active layer and the phase separation of the larger size. Finally, the device efficiency reached 7.68% when the active layer was prepared at 80 degrees centigrade, which was a great breakthrough for the "flat" PBDT-DFffBT polymer.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM914.4

【相似文献】