High-Efficiency Organic Photovoltaic Cells Based on the Solution-Processable Hole Transporting Interlayer Copper Thiocyanate (CuSCN) as a Replacement for PEDOT:PSS
High-Efficiency Organic Photovoltaic Cells Based on the Solution-Processable Hole Transporting Interlayer Copper Thiocyanate (CuSCN) as a Replacement for PEDOT:PSS
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DOI：
10.1002/aenm.201401529
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发表时间：
2015-02-04
影响因子：
27.8
通讯作者：
Anthopoulos, Thomas D.
中科院分区：
文献类型：
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作者：
Yaacobi-Gross, Nir;Treat, Neil D.;Anthopoulos, Thomas D.
DOI：10.1002/aenm。 201401529材料； 5) 阻止少数载流子流向不利电极的能力。确实发现这些中间层材料特性对 OPV 的整体性能具有深远的影响 [3-8]，更多信息可以在相关评论文章中找到。[13-18] 理想的中间层材料系统还应满足上述所有或大部分要求，与活性有机层的选择无关。迄今为止，绝大多数 OPV 器件都是基于聚 (3, 4-乙烯二氧噻吩): 聚苯乙烯磺酸 (PEDOT: PSS) 的混合物作为空穴传输层夹层系统。其广泛使用背后的一些原因包括能够提供连续和超光滑薄膜的直接处理协议、相对良好的光学透明度（80-87%）以及其深功函数（约5.1 eV），可导致与一系列常用的有机供体化合物形成欧姆接触。然而，尽管具有这些吸引人的特性，但现在已经确定，由于其酸性性质，PEDOT: PSS 可以与有机活性层发生反应 [19, 20] 并蚀刻下面的透明氧化铟锡 (ITO) 电极，[21] 这两者都限制了电池的长期运行稳定性。此外，最近的研究表明，由于其半金属性质，PEDOT: PSS 的电子阻挡性能不足。[15, 22]可以通过使用气相聚合 PEDOT (VPPPEDOT)[23] 以及各种溶剂处理去除 PSS 成分来减轻一些负面影响。[24]除了 PEDOT: PSS 基材料之外，最近还展示了许多替代溶液加工空穴传输系统，包括导电聚合物、[25, 26] 溶液加工金属氧化物、[27, 28] 石墨烯基材料、[29] 和碳纳米管。 [30]然而，尽管取得了重大进展，但仍然明显需要发现和/或开发具有改进的物理特性的新空穴传输中间层，以用于下一代廉价OPV器件和更广泛的塑料光电子学。我们最近报道了基于无机分子金属赝卤化物半导体硫氰酸铜 (I) (CuSCN) 的空穴传输（p 沟道）晶体管的开发。[31, 32] 研究表明，CuSCN 的溶液处理层由于其特有的宽带隙 (> 3.5 eV)，在电磁波谱的 UV-Vis/NIR 部分表现出固有的空穴传输特性和超高透明度。[31, 32] 这些结果表明 CuSCN 的应用有可能扩展到其他光电器件
DOI: 10.1002/aenm. 201401529 materials; and 5) ability to block minority carrier flow towards the unfavored electrode. These interlayer materials characteristics have indeed been found to have a profound influence on overall OPV performance [3–8] and further information can be found in relevant review articles.[13–18] The ideal interlayer material system should additionally satisfy all or most of the above requirements independent from the choice of the active organic layer.To date the vast majority of OPV devices are based on blends of poly (3, 4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT: PSS) as the hole transporting interlayer system. Some of the reasons behind its widespread use include the straight-forward processing protocols which are able to deliver continuous and ultra-smooth films, the relatively good optical transparency (80–87%), and its deep work function (≈ 5.1 eV) that results in the formation of Ohmic contact with a range of commonly used organic donor compounds. Despite these attractive properties, however, it is now well established that, due to its acidic nature, PEDOT: PSS can react with organic active layers [19, 20] as well as etch the underlying transparent indium tin oxide (ITO) electrode,[21] both of which limit the cell’s long-term operational stability. Moreover, recent studies suggest that the electron blocking properties of PEDOT: PSS are insufficient due to its semi-metallic nature.[15, 22] Some of the negative effects can be moderated by removal of the PSS component, using vapor phase polymerized PEDOT (VPPPEDOT)[23] as well as various solvent treatments.[24] In addition to PEDOT: PSS based materials, a number of alternative solution processable hole transporting systems were recently demonstrated including conducting polymers,[25, 26] solution processed metal oxides,[27, 28] graphene-based materials,[29] and carbon nanotubes.[30] Despite the significant progress, however, there remains a clear need for the discovery and/or development of new hole transporting interlayer with improved physical characteristics for use in next generation inexpensive OPV devices and in plastic optoelectronics more generally. We have recently reported the development of hole transporting (p-channel) transistors based on the inorganic molecular metal pseudo-halide semiconductor copper (I) thiocyanate (CuSCN).[31, 32] It was shown that solution-processed layers of CuSCN exhibit intrinsic hole transporting characteristics and ultra-high transparency across the UV–Vis/NIR part of the electromagnetic spectrum due to its characteristic wide band gap (> 3.5 eV).[31, 32] These results imply that application of CuSCN could potentially be extended to other optoelectronic devices