Abstract We report that sequential deposition of a highly crystalline polymer donor and a soluble fullerene acceptor leads to a well-defined interpenetrating network and enhanced power conversion efficiencies in bilayer polymer solar cells. Even without the use of solvent additives, layered thin films of poly[(5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl)-alt-(3,3‴-di(2-octyldodecyl)-2,2’; 5′,2’’; 5″,2‴-quaterthiophen-5,5‴-diyl)] (PffBT4T-2OD) and [6,6]-phenyl C71-butyric acid methyl ester (PC71BM), as electron donor and acceptor materials, respectively, showed bicontinuous networks similar to those of a PffBT4T-2OD:PC71BM bulk-heterojunction (BHJ) thin film processed with 1,8-diiodooctane (DIO) as a solvent additive. Transmission electron microscopy results confirmed the BHJ-like morphology of the bilayered PffBT4T-2OD/PC71BM thin films. Bilayer solar cells fabricated without the DIO additive produced a power conversion efficiency of η ≈ 7.65%, which is even higher than that of a BHJ solar cell fabricated with the DIO additive (η ≈ 7.04%). These results demonstrate that a highly crystalline polymer donor and an electron-accepting small molecule can be a good combination for efficient bilayer polymer solar cells.

中文翻译：

---

通过无添加剂连续沉积实现高效聚合物太阳能电池的电子供体-受体复合材料的双连续网络

摘要 我们报告说，高度结晶的聚合物供体和可溶性富勒烯受体的顺序沉积导致双层聚合物太阳能电池中定义明确的互穿网络和增强的功率转换效率。即使不使用溶剂添加剂，聚[(5,6-二氟-2,1,3-苯并噻二唑-4,7-二基)-alt-(3,3‴-二(2-辛基十二烷基) -2,2'; 5',2''; 5″,2‴-quaterthiophen-5,5‴-diyl)] (PffBT4T-2OD) 和 [6,6]-苯基 C71-丁酸甲酯 (PC71BM) )，分别作为电子供体和受体材料，显示出类似于用 1,8-二碘辛烷 (DIO) 作为溶剂添加剂处理的 PffBT4T-2OD:PC71BM 体异质结 (BHJ) 薄膜的双连续网络。透射电子显微镜结果证实了双层 PffBT4T-2OD/PC71BM 薄膜的 BHJ 样形态。未添加 DIO 添加剂制造的双层太阳能电池的功率转换效率为 η ≈ 7.65%，甚至高于使用 DIO 添加剂制造的 BHJ 太阳能电池的功率转换效率 (η ≈ 7.04%)。这些结果表明，高度结晶的聚合物供体和电子接受小分子可以是高效双层聚合物太阳能电池的良好组合。