Photophysics and Optoelectronics, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, Groningen, 9747AG, The Netherlands.
INRS-EMT Centre for Energy, Materials and Telecommunication, 1650 Boul. Lionel Boulet, Varennes, QC, J3X 1S2, Canada.
Macromol Rapid Commun. 2020 Jun;41(11):e2000124. doi: 10.1002/marc.202000124. Epub 2020 May 5.
Blends of semiconducting (SC) and ferroelectric (FE) polymers have been proposed for applications in resistive memories and organic photovoltaics (OPV). For OPV, the rationale is that the local electric field associated with the dipoles in a blend could aid exciton dissociation, thus improving power conversion efficiency. However, FE polymers either require solvents or processing steps that are incompatible with those required for SC polymers. To overcome this limitation, SC (poly(3-hexylthiophene)) and FE (poly(vinylidene fluoride-trifluoroethylene)) components are incorporated into a block copolymer and thus a path to a facile fabrication of smooth thin films from suitably chosen solvents is achieved. In this work, the photophysical properties and device performance of organic solar cells containing the aforementioned block copolymer consisting of poly(vinylidene fluoride-trifluoroethylene): P(VDF-TrFE), poly(3-hexylthiophene): P3HT and the electron acceptor phenyl-C -butyric acid methyl ester: [60]PCBM are explored. A decrease in photovoltaic performance is observed in blends of the copolymer with P3HT:[60]PCBM, which is attributed to a less favorable nanomorphology upon addition of the copolymer. The role of lithium fluoride (the cathode modification layer) is also clarified in devices containing the copolymer, and it is demonstrated that ferroelectric compensation prevents the ferroelectricity of the copolymer from improving photovoltaic performance in SC-FE blends.
将半导体（SC）和铁电（FE）聚合物共混，以应用于电阻式存储器和有机光伏（OPV）。对于 OPV，其基本原理是共混物中偶极子产生的局部电场有助于激子解离，从而提高功率转换效率。然而，FE 聚合物要么需要溶剂，要么需要与 SC 聚合物不兼容的加工步骤。为了克服这一限制，SC（聚（3-己基噻吩））和 FE（聚（偏二氟乙烯-三氟乙烯））组分被整合到嵌段共聚物中，从而实现了从合适选择的溶剂中制备光滑薄膜的简便方法。在这项工作中，研究了含有上述嵌段共聚物的有机太阳能电池的光物理性质和器件性能，该嵌段共聚物由聚（偏二氟乙烯-三氟乙烯）：P（VDF-TrFE）、聚（3-己基噻吩）：P3HT 和电子受体苯基-C-丁酸甲酯：[60]PCBM 组成。共聚物与 P3HT：[60]PCBM 的共混物的光伏性能下降，这归因于共混物中添加共聚物后纳米形态变得不利。还阐明了含共聚物器件中氟化锂（阴极修饰层）的作用，证明铁电补偿阻止了共聚物的铁电性在 SC-FE 共混物中提高光伏性能。
