基于ZnS材料的纺织基交流电致发光器件研究现状及展望

Research status and prospect of textile-based flexible AC electroluminescent devices based on ZnS materials

宽禁带Ⅱ-Ⅵ化合物ZnS是电致发光材料的最佳基质之一,以其掺杂物为发光材料主体的柔性交流电致发光器件具有优良的机械性能、简易的制造工艺、均匀的发光性能及较低的生产成本等特点,被视为未来极有前途的柔性显示设备,在可穿戴设备、仿生伪装、智能交互及软机器人等领域具有广阔应用前景。近年来,将交流电致发光原理与纺织技术相融合的研究策略,成为柔性发光设备领域的研究热点。本文结合近年来纤维基、织物基柔性交流电致发光器件在照明显示、信息交互、智能穿戴、视觉传感及潮流装饰等领域的研究,对发光器件的结构、发光机理、性能提升、优化方案进行了分类、综述及分析,并对柔性交流电致发光器件的未来发展进行了展望。

With the rise of soft robot,smart wearable,human-computer interaction and other fields,flexible electroluminescent devices are developing vigorously.Electroluminescence,also known as electric field luminescence,is a phenomenon that converts electrical energy directly into light energy.In the early 20thcentury,Destriau discovered that ZnS powder suspended in an insulating medium would emit light under an electric field.In the middle of the 20thcentury,after the emergence of transparent glass,the structure of“sandwich”electroluminescent devices was basically established,which could obtain stable electroluminescence under an electric field.This promoted the development of electronic display devices.The wide band gapⅡ-Ⅵcompound ZnS is one of the best hosts for electroluminescent materials,and flexible alternating current(AC)electroluminescence devices based on ZnS dopant as the main luminescent material have the characteristics of excellent mechanical properties,simple manufacturing process,uniform luminescence performance and low production cost.Therefore,the above-mentioned compound ZnS is regarded as a very promising flexible display device in the future.It has broad application prospects in the fields of wearable devices,bionic camouflage,intelligent interaction and soft robots.In recent years,the research strategy of integrating the principle of AC electroluminescence with textile technology has become a research hotspot in the field of flexible light-emitting devices.To achieve a macroscopic understanding of research in the field,we discuss based on the recent research on thin-film-based and textile-based flexible alternating current electroluminescent devices in the fields of lighting display,information interaction,smart wear,visual sensing and trend decoration.In this paper,the structure,luminescence mechanism,performance improvement and optimization scheme of electroluminescence devices are classified,reviewed and analyzed.Firstly,based on the structure of the flexible electroluminescent device,the luminescence mechanism of the device is analyzed by each functional layer of the device,and the high operating voltage limitation,brightness enhancement bottleneck,mechanical stability and self-healing of the device are discussed.Secondly,in view of the research hotspot of AC electroluminescent fabrics,the preparation process,characteristics and application advantages of textile-based AC electroluminescent devices are discussed in detail from the fiber-based and fabric-based perspectives.Specifically,fiber-based AC electroluminescent devices can be knitted or woven to achieve seamless integration,maximizing the flexibility and permeability of AC electroluminescent fabrics.However,due to its complex process and small size,there are still shortcomings in cost and device brightness,uniformity,wear resistance,stability and other properties.Moreover,the luminescence performance,mechanical performance and wearable performance of fiber integrated into fabric also need further exploration and research.The fabric-based AC electroluminescence devices can achieve good brightness,uniformity,flexibility and mechanical stability,but the dense stacking of functional materials reduces the flexibility and moisture permeability,which limits the wearable comfort performance to a large extent.In addition,for miniaturization and portable applications,self-powered electroluminescence devices have attracted much attention.Finally,the future development of flexible AC electroluminescent devices is prospected.The combination of electroluminescent materials and fabrics will continue to attract extensive attention from researchers,and show broader application prospects in wearable devices,bionic camouflage,intelligent applications and soft robots.First of all,diversified application scenarios and complex usage requirements put forward higher requirements for AC electroluminescent devices,and multifunctional flexible AC electroluminescent devices will usher in a booming period of development.Secondly,the road to practical application of high-performance wearable smart AC electroluminescent devices must overcome the difficulties of wearing comfort and use safety.On the basis of stable luminescent properties and mechanical properties,flexible AC electroluminescent fabrics can significantly improve wearing comfort and create better landing conditions for their wearable applications,which will be an important research direction for AC electroluminescent devices.With the help of the mature production system and technology of textile enterprises,the effective integration of luminous principle and textile technology can be realized.It may be a feasible way to reduce costs and simplify the process,which may effectively promote the large-scale industrialization process of wearable AC electroluminescent devices.