Yin Hexing, Zhu Yuan, Youssef Kareem, Yu Zhibin, Pei Qibing
Soft Materials Research Laboratory, Department of Materials Science and Engineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, CA, 90015, USA.
Department of Industrial and Manufacturing Engineering, High-Performance Materials Institute, FAMU-FSU College of Engineering, Florida State University, Tallahassee, FL, 32310, USA.
Adv Mater. 2022 Jun;34(22):e2106184. doi: 10.1002/adma.202106184. Epub 2021 Dec 22.
Stretchable electroluminescent (EL) devices are obtained by partitioning a large emission area into areas specifically for stretching and light-emission (island-bridge structure). Buckled and textile structures are also shown effective to combine the conventional light emitting diode fabrication with elastic substrates for structure-enabled stretchable EL devices. Meanwhile, intrinsically stretchable EL devices which are characterized with uniform stretchability down to microscopic scale are relatively less developed but promise simpler device structure and higher impact resistance. The challenges in fabricating intrinsically stretchable EL devices with high and robust performance are in many facets, including stretchable conductors, emissive materials, and compatible processes. For the stretchable transparent electrode, ionically conductive gel, conductive polymer coating, and conductor network in surface of elastomer are all proven useful. The stretchable EL materials are currently limited to conjugated polymers, conjugated polymers with surfactants and ionic conductors added to boost stretchability, and phosphor particles embedded in elastomer matrices. These emissive materials operate under different mechanisms, require different electrode materials and fabrication processes, and the corresponding EL devices face distinctive challenges. This review aims to provide a basic understanding of the materials meeting both the mechanical and electronic requirements and important techniques to fabricate the stretchable EL devices.
可拉伸电致发光（EL）器件是通过将大的发光区域划分为专门用于拉伸和发光的区域（岛桥结构）来获得的。弯曲结构和纺织结构也被证明能有效地将传统发光二极管制造工艺与弹性基板相结合，以制造具有结构可拉伸性的EL器件。同时，具有微观尺度均匀拉伸性的本征可拉伸EL器件的发展相对较少，但有望实现更简单的器件结构和更高的抗冲击性。制造高性能和高稳定性的本征可拉伸EL器件面临多方面挑战，包括可拉伸导体、发光材料和兼容工艺等。对于可拉伸透明电极，离子导电凝胶、导电聚合物涂层以及弹性体表面的导体网络都已被证明是有用的。目前，可拉伸EL材料仅限于共轭聚合物、添加表面活性剂和离子导体以提高拉伸性的共轭聚合物，以及嵌入弹性体基质中的磷光体颗粒。这些发光材料的工作机制不同，需要不同的电极材料和制造工艺，相应的EL器件也面临着独特的挑战。本综述旨在提供对满足机械和电子要求的材料以及制造可拉伸EL器件的重要技术的基本理解。
