Cavendish Laboratory, University of Cambridge, J. J. Thomson Ave., Cambridge CB3 0HE, UK.
Small. 2012 Jun 25;8(12):1920-7. doi: 10.1002/smll.201102382. Epub 2012 Apr 2.
Films of the fullerene derivatives [6,6]-phenyl-C(61)-butyric acid methyl ester (PC(61) BM) and [6,6]-phenyl-C(71)-butyric acid methyl ester (PC(71) BM) are patterned on silicon nitride membranes using photolithography to study, with X-ray spectromicroscopy, the lateral, solid-state diffusion of fullerene derivatives into conjugated polymer films. After patterning of the fullerene film, a film of conjugated polymer is laminated on top and the structure is annealed in order to study lateral intermixing and facilitate measurement of fullerene miscibility. Lateral intermixing of polymer and fullerene readily occurs for poly(2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT) and regiorandom poly(3-hexylthiophene) (RRa-P3HT). A 42 wt.% miscibility of PC(61) BM in PBTTT is measured, while miscibilities of 20 and 41 wt.% are measured for PC(61) BM and PC(71) BM, respectively, in RRa-P3HT, thereby demonstrating a significant difference in the miscibilities of these two fullerene derivatives. For regioregular poly(3-hexylthiophene) (RR-P3HT), incomplete lateral intermixing of fullerene and RR-P3HT is observed with PCBM crystallite formation competing with the lateral diffusion of PCBM molecules into the polymer film.
富勒烯衍生物[6,6]-苯基-C(61)-丁酸甲酯（PC(61)BM）和[6,6]-苯基-C(71)-丁酸甲酯（PC(71)BM）的薄膜通过光刻技术在氮化硅膜上进行图案化，以使用 X 射线光谱显微镜研究富勒烯衍生物在共轭聚合物薄膜中的横向固态扩散。在富勒烯薄膜图案化后，将一层共轭聚合物层压在顶部，并对结构进行退火，以研究横向混合并促进富勒烯混溶性的测量。聚合物和富勒烯的横向混合很容易发生在聚[2,5-双（3-十四烷基噻吩-2-基）噻吩[3,2-b]噻吩]（PBTTT）和区域无规聚（3-己基噻吩）（RRa-P3HT）中。测量到 PC(61)BM 在 PBTTT 中的 42wt%混溶性，而在 RRa-P3HT 中 PC(61)BM 和 PC(71)BM 的混溶性分别为 20wt%和 41wt%，从而证明这两种富勒烯衍生物的混溶性有显著差异。对于规则聚（3-己基噻吩）（RR-P3HT），观察到富勒烯和 RR-P3HT 的不完全横向混合，PCBM 晶核形成与 PCBM 分子向聚合物薄膜中的横向扩散竞争。
