【作者】 张斌；

【导师】 杨伟；

【作者基本信息】 华南理工大学 ， 高分子化学与物理， 2013， 博士

【摘要】 聚合物太阳电池作为一类新型的电池类型，因其重量轻、价格便宜、制备简单、可制作成大面积以及结构易调节等优点，得到了学术界和工业界极大的关注。在聚合物太阳电池研究领域中，作为电子给体的窄带隙共轭聚合物是研究的一个重点。作为一个理想的电子给体聚合物，需要具有宽的光谱吸收、高的短路电流密度、高的开路电压和高的填充因子。因此，本论文主要研究工作涉及设计和合成新型的D-A型窄带隙共轭聚合物，以及通过不同取代基团的调节，获得具有不同HOMO能级的聚合物，从而达到调节聚合物太阳电池开路电压的目的。首先，合成了新型的辛氧基取代的苯并呋咱类衍生物。该类衍生物在常用有机溶剂中具有很好的溶解性，有利于提高聚合物在合成过程中的溶解性，从而可以获得高分子量的窄带隙共轭聚合物。另外，该衍生物也具有很好的平面性，从而可以获得具有优秀太阳光谱吸收能力的聚合物。通过将该衍生物分别与咔唑单元、吲哚咔唑单元和噻吩单元进行交替共聚，得到了一系列的基于辛氧基取代的苯并呋咱类窄带隙聚合物。其中，基于咔唑和辛氧基取代的苯并呋咱类衍生物的共聚物具有最优秀的光伏性能，能量转换效率达到了5.48%。然后，设计和合成了一系列的不同基团取代的基于三苯胺单元的窄带隙聚合物。通过不同的供电子性的烷基和烷氧基、以及吸电子性的三氟甲基修饰三苯胺单元，以达到对最终聚合物的HOMO能级的调节，从而可以对该类聚合物太阳电池的开路电压达到一个调节的作用。供电子性的烷基和烷氧基可以提高聚合物的HOMO能级和降低聚合物太阳电池的开路电压；然而，吸电子性的三氟甲基基团可以降低聚合物的HOMO能级和提高聚合物太阳电池的开路电压。最终，基于此类不同基团取代的三苯胺单元的窄带隙聚合物制备成的太阳电池的开路电压可以从0.70V调节到1.00V。最后，设计和合成了两个9-位被C=N双键取代的芴类衍生物的窄带隙共轭聚合物。通过9-位被C=N双键取代，可以提高芴类聚合物的分子平面性，有利于提高聚合物分子主链间的π-π相互堆积。另外，吸电子性的C=N双键可以降低聚合物的带隙，提高其对太阳光谱的吸收能力。其中，基于此类芴衍生物的聚合物太阳电池的能量转换效率能够达到0.5%左右。更多还原

【Abstract】 Polymer solar cells(PSCs), as one kind of novel solar cells, are becoming increasinglymore and more attractive academically and industrially, because of its versatile merits in lightweight, cheap price, feasible fabrication, large-scale area and easy structure tuning. In theresearch field of PSCs, the preparation of low band-gap donor materials is the important issue.As an ideal donor material, it must exist broad solar absorption, high short current density,high open circuit voltage and high fill factor.Therefore, in this dissertation, we designed and synthesized novel D-A narrow band-gappolymers; and through the fine tuning by the different substituted groups, the polymers withdifferent HOMO energy levels were obtained, which can tune the open circuit voltage inPSCs feasibly.Preliminarily, an octyloxy substituted benzofunazan derivative was synthesized. Thisderivative had good solubility in common organic solvents, which was beneficial forenhancing the polymers’ solubility in polymerization and acquiring the narrow band-gappolymers with high molecular weight. Moreover, it had good planarity which can increasepolymrs’ solar absorption. Through the polymerization between this derivative and carbazole,indocarbazole or thiophene, a series of narrow band-gap polymers based on octyloxysubstituted benzofunazan were synthesized. In these polymers, the one containing octyloxysubstituted benzofunazan derivative and carbazole had the best photovoltaic performance withthe power conversion efficiency of5.48%.Furthermore, a series of different groups substituted triphenylamine based narrowband-gap polymers were designed and synthesized. Through the decoration by theelectron-donating alkyl and alkoxy groups, and electron-withdrawing trifluoromethyl groupsin triphenylamine, the HOMO energy levels of target polymers could be adjusted feasibly, andultimately the open circuit voltages in these PSCs were tuned. The electorn-donating alkyland alkoxy groups in triphenylamine can increase the HOMO energy level and decrease theopen circuit voltage in PSCs; on the other hand, the electron-withdrawing trifluoromethlygroups could decrease the HOMO energy level and increase the open circuit voltage. Finally,the open circuit voltages in PSCs based on these narrow band-gap polymers can be tuned between0.70V and1.00V.At last, two fluorene-derivatives based polymers, which were substituted by the C=Ndouble bonds in9-position, were designed and prepared. Through the substitution in9-position by the C=N double bonds, it can increase the molecular planarity which wasbeneficial for enhancing the π-π stacking between the polymer main chains. On the other side,the electron-withdrawing C=N double bonds can decrease the polymers’ band gap whichwould increase the polymers’ solar absorpation. The photovoltaic properties based on thesepolyfluorenes can reach to the power conversion efficiency of about0.5%.更多还原