The effects of copper metalation of tetrabenzoporphyrin on the properties and performance of organic solar cells are studied. Tetrabenzoporphyrin (BP) and copper tetrabenzoporphyrin (CuBP) are both solution processed from soluble precursor materials and thermally converted in the thin film. Despite high field-effect hole mobility above 1 cm2 V−1 s−1, the power conversion efficiency (PCE) of solar cell devices with CuBP is severely diminished compared to those with BP. Conducting atomic force microscopy (c-AFM) is used to show that CuBP films are highly conductive in the direction perpendicular to the substrate, relative to those comprising BP. By analyzing the donor absorption characteristics as well as the external quantum efficiency and short-circuit current density of bilayer OPV devices as a function of donor layer thickness, it is determined that the differences in performance are likely due to a prohibitively short effective exciton diffusion length (LD) in the metalated derivative. By modeling the external quantum efficiency of bilayer OPV devices, we are able to approximate this difference in effective LD to be 15 nm for BP and 2 nm for CuBP.
研究了
铜金属化四苯并
卟啉对有机太阳能电池特性和性能的影响。四苯并
卟啉(BP)和四苯并
卟啉铜(CuBP)都是由可溶性前体材料经溶液加工而成,并在薄膜中进行热转换。尽管场效应空穴迁移率高于 1 cm2 V-1 s-1,但与使用 BP 的太阳能电池相比,使用 CuBP 的太阳能电池器件的功率转换效率(PCE)严重降低。传导原子力显微镜(c-A
FM)表明,与含有 BP 的薄膜相比,CuBP 薄膜在垂直于基底的方向上具有高导电性。通过分析供体吸收特性以及双层 OPV 器件的外部量子效率和短路电流密度与供体层厚度的函数关系,可以确定性能差异可能是由于
金属化衍
生物中有效激子扩散长度(LD)过短造成的。通过对双层 OPV 器件的外部量子效率进行建模,我们可以将有效 LD 的差异大致估算为:BP 为 15 nm,CuBP 为 2 nm。