Department of NanoEngineering, University of California, San Diego , 9500 Gilman Drive, Mail Code 0448, La Jolla, California 92093-0448, United States.
Chem Rev. 2017 May 10;117(9):6467-6499. doi: 10.1021/acs.chemrev.7b00003. Epub 2017 Mar 25.
Mechanical deformability underpins many of the advantages of organic semiconductors. The mechanical properties of these materials are, however, diverse, and the molecular characteristics that permit charge transport can render the materials stiff and brittle. This review is a comprehensive description of the molecular and morphological parameters that govern the mechanical properties of organic semiconductors. Particular attention is paid to ways in which mechanical deformability and electronic performance can coexist. The review begins with a discussion of flexible and stretchable devices of all types, and in particular the unique characteristics of organic semiconductors. It then discusses the mechanical properties most relevant to deformable devices. In particular, it describes how low modulus, good adhesion, and absolute extensibility prior to fracture enable robust performance, along with mechanical "imperceptibility" if worn on the skin. A description of techniques of metrology precedes a discussion of the mechanical properties of three classes of organic semiconductors: π-conjugated polymers, small molecules, and composites. The discussion of each class of materials focuses on molecular structure and how this structure (and postdeposition processing) influences the solid-state packing structure and thus the mechanical properties. The review concludes with applications of organic semiconductor devices in which every component is intrinsically stretchable or highly flexible.
机械变形性是有机半导体诸多优势的基础。然而，这些材料的机械性能是多样化的，而允许电荷传输的分子特性会使材料变得坚硬和易碎。本综述全面描述了控制有机半导体机械性能的分子和形态参数。特别关注机械变形性和电子性能如何共存。综述首先讨论了各种类型的柔性和可拉伸器件，特别是有机半导体的独特特性。然后讨论了与可变形器件最相关的机械性能。特别是，它描述了低模量、良好的附着力以及断裂前的绝对可拉伸性如何实现稳健的性能，以及如果戴在皮肤上的话如何实现机械“不可感知性”。在讨论三类有机半导体的机械性能之前，先描述了计量技术：π 共轭聚合物、小分子和复合材料。每一类材料的讨论都集中在分子结构上，以及这种结构（和沉积后处理）如何影响固态堆积结构，从而影响机械性能。综述最后介绍了有机半导体器件在其中每个组件本质上都是可拉伸或高度灵活的应用。
