Nanoconfining Optoelectronic Materials for Enhanced Performance and Stability
Nanoconfining Optoelectronic Materials for Enhanced Performance and Stability
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DOI：
10.1021/acs.chemmater.9b01707
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发表时间：
2019-07-23
影响因子：
8.6
通讯作者：
Lee, Stephanie S.
中科院分区：
文献类型：
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作者：
Kong, Xiaoqing;Zong, Kai;Lee, Stephanie S.
光电子有源层的溶液加工有望开启从可卷曲显示器到智能纺织品的技术新纪元，但这些材料的加工仍然存在关键挑战。虽然这些化合物(包括有机小分子和聚合物以及金属卤化物钙钛矿)的溶液沉积是降低制造成本的关键，但溶液处理的快速、不受控制的性质总是会导致形成动力学陷阱薄膜，其异质和缺陷跨越多个长度尺度，从而降低器件性能。考虑到分子作为溶剂从活性层蒸发出来的有限时间，通常是几秒钟，使用纳米孔支架来选择所需的结晶结果是解决这一关键问题的一种有前途的方法。随着晶体尺寸的减小，其表面自由能在决定其形态和结构方面起着越来越重要的作用。通过将结晶限制在支架的亚微米孔内，可以利用这种表面自由能效应来选择特定的晶型和晶体取向。在这个视角下，我们重点介绍了利用纳米多孔支架来稳定高效晶型的金属卤化物钙钛矿，以及引导有机半导体晶体的横向和垂直方向，分别优化面内和面外的电荷传输。关键的是，使用纳米孔支架的可伸缩溶液相沉积方法的例子被强调为潜在的商业化目标。
The solution processing of optoelectronic active layers promises to usher in a new era of technologies, from rollable displays to smart textiles, but critical challenges remain in the processing of these materials. While solution based deposition of these compounds, including organic small-molecules and polymers and metal-halide perovskites, is key to driving down manufacturing costs, the rapid, uncontrolled nature of solution processing invariably results in the formation of kinetically trapped films, with heterogeneities and defects spanning multiple length scales that degrade device performance. Given such finite time, usually on the order of seconds, for molecules to organize as solvent evaporates from the active layers, the use of nanoporous scaffolds to select for desired crystallization outcomes is a promising approach to addressing this critical issue. As the size of crystals decreases, their surface free energy plays an increasingly important role in dictating their morphology and structure. By confining crystallization within the sub-micrometer pores of scaffolds, such surface free energy effects can be exploited to select for specific polymorphs and crystal orientations. In this Perspective, we highlight the use of nanoporous scaffolds to stabilize high-performing polymorphs of metal-halide perovskites, as well as guide the orientation of organic semiconductor crystals both laterally and vertically for optimized in-plane and out-of-plane charge transport, respectively. Critically, examples of scalable solution-phase deposition methods using nanoporous scaffolds are highlighted as potential targets for commercialization.