Self‐Organized Buffer Layers in Organic Solar Cells
Self‐Organized Buffer Layers in Organic Solar Cells
复制标题
DOI：
10.1002/adma.200792876
复制
发表时间：
2008-06
影响因子：
29.4
通讯作者：
Qingshuo Wei;T. Nishizawa;K. Tajima;K. Hashimoto
中科院分区：
文献类型：
--
作者：
Qingshuo Wei;T. Nishizawa;K. Tajima;K. Hashimoto
有机分子的自组装是一种极具吸引力的纳米结构制备方法。[1-4]在纳米尺度上控制层状结构在薄膜有机器件中是特别期望的，因为这在很大程度上影响膜的电学、光学和机械性质。为了自发地制造这种多层结构，需要仔细控制驱动力，例如相分离、结晶或材料的表面能。例如，Goffri等人报道了在混合物膜中聚（3-己基噻吩）（P3 HT）和聚乙烯之间自发形成双层结构。[5]聚乙烯的结晶诱导P3 HT在有机半导体/电介质界面处的有效封装，从而产生机械稳健和高性能的薄膜晶体管。最近，Krishnan等人报道了一种在纳米级获得自组织多层结构的新方法。[6]由纳米颗粒和聚合物的混合物形成的旋涂膜被简单地退火，以实现纳米颗粒由于熵和双折射驱动力而在基底表面上的累积。这些开创性的研究为各种有机薄膜器件的制造提出了新的有吸引力的方法。然而，功能材料的自组织双层或多层结构的研究仍然非常有限，仍然具有挑战性。在本论文中，我们报道了一种通过控制材料表面能在有机薄膜中形成层状结构的新方法及其在有机太阳能电池中的应用。众所周知，具有低表面能的材料如氟化或硅酮化合物在涂覆期间优选迁移到空气/液体界面。[7-10]这就是所谓的表面偏析，它是由总能量驱动的
The self-organization of organic molecules is an attractive approach for nanostructure fabrication.[1–4] The control of layered structures on the nanoscale is particularly desirable in thin-film organic devices because this largely affects the electrical, optical, and mechanical properties of the films. To spontaneously fabricate such multilayered structures, the careful control of driving forces such as phase separation, crystallization, or the surface energy of the materials is necessary. For example, Goffri et al. reported the spontaneous formation of bilayer structures between poly (3-hexylthiophene)(P3HT) and polyethylene in mixture films.[5] The crystallization of polyethylene induces the effective encapsulation of P3HT at the organicsemiconductor/dielectric interface, resulting in mechanically robust and high-performance thin-film transistors. Very recently, Krishnan et al. reported a new method of obtaining self-organized multilayer structures at the nanoscale level.[6] The spin-coated films from the mixtures of the nanoparticles and the polymers were simply annealed to achieve the accumulation of the nanoparticles to the substrate surface owing to the entropic and enthalpic driving forces. These pioneering studies proposed new attractive approaches for the fabrication of various organic thin-film devices. However, studies of the self-organized bilayer or multilayer structure of functional materials are still very limited and remain challenging. Moreover, their applications to actual electronic devices have been hardly explored.In the present work, we report a novel, simple approach to form layered structures in organic thin films by controlling the surface energy of the materials and its application to organic solar cells. It is well-known that materials having a low surface energy such as ffuorinated or silicone compounds prefer to migrate to the air/liquid interface during coating.[7–10] This is called surface segregation, which is driven by the total energy