标题: 可热交联富勒烯衍生物和阳极缓冲层用于溶液式制程高分子太阳能电池和钙钛矿太阳能电池
Thermally Crosslinkable Fullerene Derivative and Anodic Buffer Layers Used In Solution-processed Polymer Solar Cells and Perovskite Solar Cells
作者: 赵翊翔
许千树
Chao, Yi-Hsiang
Hsu, Chain-Shu
应用化学系硕博士班
关键字: 高分子太阳能电池;钙钛矿太阳能电池;富勒烯衍生物;氧化钒;介面工程;形貌控制;Polymer Solar Cells;Perovskite Solar Cells;Fullerene Derivatives;Vanadium Oxide;Interfacial Engineering;Morphology Control
公开日期: 2016
摘要: 本研究致力于研究可热交联富勒烯衍生物和阳极缓冲层用于高分子太阳能电池与钙钛矿太阳能电池之介面工程、形貌控制或稳定性的研究。
本研究第一部分以湿式氧化石墨烯与过渡金属氧化物复合层当阳极缓冲层用以提升 Poly(3-hexylthiophene) (P3HT) : [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) 所形成的混掺体异质结构高分子太阳能电池,本缓冲层具备帮助电洞收集、介面修饰和较佳的大气稳定性,这些目标的达成,有利于制备全湿式制程反式结构有机高分子太阳能电池,同时,以石墨烯复合氧化钒和石墨烯复合氧化钼所形成之阳极缓冲层,其元件光电转换效率可以达到 4.1 % 和 3.4 %,更进一步地,使用低能隙材料 poly{(5,6-difluorobenzo-2,1,3-thiadiazole-4,7-diyl)-alt-(3’,4”-di-(2-octyldodecyl)-2,2’;5’,2”;5’’,2’’’-quaterthiophene-5,5’’’-diyl)} (PTh4FBT) 搭配石墨烯复合氧化钒所形成的阳极氧化层其效率可以达到 6.7 %,与蒸镀制成三氧化钼有着相同的效率。最后,我们也使用 X 光光电子纵向分布鉴定与萤光放光图谱来分析,我们发现氧化石墨烯能够阻挡氧化钒先驱物的下陷,改善主动层缺陷,而能够提升元件效率。
本研究之第二部份以紫质嵌入高分子作为一个互补吸收的策略,而适当的紫质比例可以产生全可见光谱吸收的分子,其元件短路电流可以大幅提升从 13.5 mA/cm2到 14.9 mA/cm2 ,所以元件光电效率可以从 6.8 % 到8 %,为目前紫质嵌入系统高分子光电转换效率报导的最高效率值。更进一步的使用 1-Chloronaphthalene (1-CN) 为溶剂添加剂,帮助改善主动层溶液之溶解度和 cross-linked [6,6]-phenyl-C61-butyric styryl dendron ester (C-PCBSD) 为介面修饰层改善元件漏电流的情形,其元件短路电流可提升至 16.1 mA/cm2,效率值可以提升至 8.6 %。这紫质嵌入高分子共聚的策略规避了一般开路电压和短路电流权衡现象,我们希望能够作为未来设计 D-A (Donor-Acceptor) 光电高分子的策略之一。
本研究之第三部分以C-PCBSD 混掺 Fulleropyrrolidinium ions (FPI) 其比例达1:1时,经由可见光吸收光谱鉴定,仍然保有抗溶剂等性质。由于 C-PCBSD 在元件上其电子迁移率较低,我们提出以FPI 混掺在 C-PCBSD 薄膜中产生阴离子诱导电荷转移来解决此问题,而FPI混掺后的 C-PCBSD 薄膜在空间电荷限制电流的元件上,可证实能提高电子迁移率,其μe 由 1.3 × 10-5 cm2V-1s-1 提升 6.0 × 10-5 cm2V-1s-1 ,另外我们将其应用在有机高分子太阳能电池元件上面,作为氧化锌的修饰层,使用Poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b’]dithiophene-2,6-diyl-alt-(4-(2-ethylhexanoyl)-thieno[3,4-b]thiophene-)-2-6-diyl)] (PBDTTT-C-T) : [6,6]-Phenyl-C71-butyric acid methyl ester (PC71BM) 作为主动层材料,其元件短路电流可以从 13.1 mA/cm2提升到 15.4 mA/cm2 ,所以元件光电效率可以从 5.8 % 到6.7 %,更进一步地,将此阴极缓冲层用在钙钛矿太阳能电池上,其元件短路电流可以大幅提升从 14.1 mA/cm2到 19.1 mA/cm2,所以元件光电效率可以从 7.0 % 到11.9 %,除此之外此阴极缓冲层也改善了钙钛矿太阳能电池的热稳定性。
本研究之第四部份以C-PCBSD 混掺于 CH3NH3PbIxCl3-x主动层中形成混掺体异质结构用于改善钙钛矿太阳能电池之元件表现再现性差、大气下不稳定与薄膜针孔孔洞等问题。C-PCBSD 可改善钙钛矿主动层表面覆盖率与致密度,其可抵抗湿气侵入,阻止溶剂侵蚀,可抑制漏电流的产生。其元件短路电流可以大幅提升从 18.7 mA/cm2到 22.3 mA/cm2,填充因子也从 70 %上升至 77 %,所以元件光电效率可以从 12.1 % 到17.2 %。最后,我们也使用可见光光谱图和2D grazing incidence x-ray diffraction (2D-GIXRD)光绕射图谱来鉴定与分析其薄膜在大气下稳定性。其结果显示,C-PCBSD混掺 CH3NH3PbIxCl3-x 薄膜元件放在大气下180小时之后,其元件能维持在相比原本起始效率的87 %对比无混掺C-PCBSD 的CH3NH3PbIxCl3-x 薄膜元件其相比原本起始效率的50% ,这显示其元件有良好的大气稳定性。
The research is aimed to study the crosslinkable fullerene derivative and anodic buffer layer used in interfacial engineering, morphology control and stability of polymer solar cells and perovskite solar cell. In the first part of this study, high efficiency and long-term stable P3HT : PC61BM -based polymer bulk-heterojunction polymer solar cells (BHJPSC) are achieved by incorporating solution-processed composite anodic buffer layers (ABLs) into the devices to serve three functions : hole collection, interface optimization and long term stability. Through the excellent electron-blocking ability of the solution-processed graphene oxide (sGO) layer allows the sGO / vanadium oxide (VOx) and sGO / molybedenum oxide (MoOx) composite ABLs based BHJPSCs to reach power conversion efficiency (PCE) of 4.1 % and 3.4 %, respectively. Furthermore, when a low band gap (LBG) polymer PTh4FBT was used, its BHJPSCs containing sGO/VOx layer exhibits nearly identical PCE value of 6.7 % with the reference cell containing evaporated MoO3 interlayer. The results demonstrate that the potential of sGO/VOx as a highly efficient ABL in inverted PSCs。Finally, we use X-ray photoelectron spectroscopy (XPS) to characterize and analyze the penetration for VOx precursor. We found that sGO can effectively block the penetration of VOx precursor and improved the performance of devices.
In the second part of this study, porphyrin-incorporated polymers were synthesized to circumvent the Voc-Jsc trade-offs in BHJPSCs. The rational design of porphyrin-moiety as light harvest unit onto backbone of copolymer enhanced the solubility and made it as a panchromatic light absorber. As a result, the short circuit current of device is enhanced from 13.1 mA/cm2 to 15.4 mA/cm2 with significantly improved power conversion efficiencies up to 8.0 %. Moreover, a best device performance with PCE value of 8.6 % was achieved when a processing additive (1-CN) and a C-PCBSD cathodic interlayer were introduced into the device fabrication.
In the third part of this study, we developed a new cathodic buffer layer consisting of a C-PCBSD matrix and an ionic FPI dopant. Through the characterization of UV-vis spectrum, the C-PCBSD matrix can well protect the FPI dopant from washed. The incorporation of FPI can improve the electron mobility via an anion induced charge transfer (AIET) mechanism while maintaining the solvent-resistant property of the crosslinked layer. The zinc oxide (ZnO) combined with C-PCBSD / FPI layer can effectively and universally improve the performance of planar heterojunction polymer solar cells (PHJPSCs), BHJPSC, and organic metallohalide perovskite solar cells (OMPSCs). The enhanced PCE can be ascribed to the increasement of device’s short circuit current from 0.3 mA/cm2, 13.1 mA/cm2, and 14.1 mA/cm2 to 2.3 mA/cm2, 15.4 mA/cm2, and 19.1 mA/cm2, respectively. Moreover, the insertion of C-PCBSD / FPI layer can improve the thermal stability of the device by preventing direct contact between ZnO and CH3NH3PbI3 layer in OMPSCs.
In the final part of this study, we demonstrate BHJ-OMPSCs with improved device characteristics and stability simultaneously by blending the C-PCBSD with CH3NH3PbIxCl3-x. The C-PCBSD can form solvent-resistant network both on the surface and in the bulk of the perovskites, which can resist the moisture incursion to prevent the interfaces from erosion, and to passivate the voids or pinholes generated in the bulk active layer to suppress the leakage. As a result, the device showed largely increased short circuit current from 18.7 mA/cm2 to 22.3 mA/cm2 with PCE up to 17.2 %. Moreover, CH3NH3PbIxCl3-x blending C-PCBSD thin films are characterized by UV-Vis spectrospcopy, and 2D-GIXRD to evulate the ambient stability. After keeping in ambient air for 180 hours, the device containing C-PCBSD still maintain 87 % of its original PCE value, while the device without C-PCBSD will droped to 50 %.
URI: http://etd.lib.nctu.edu.tw/cdrfb3/record/nctu/#GT070052511
http://hdl.handle.net/11536/139292
显示于类别:Thesis