Self-healable electroluminescent devices

Abstract

Electroluminescent (EL) devices have been extensively integrated into multi-functionalized electronic systems in the role of the vitally constituent light-emitting part. However, the lifetime and reliability of EL devices are often severely restricted by concomitant damage, especially when the strain exceeds the mechanical withstanding limit. We report a self-healable EL device by adopting a modified self-healable polyacrylic acid hydrogel as the electrode and a self-healable polyurethane as a phosphor host to realize the first omni-layer-healable light-emitting device. The physicochemical properties of each functionalized layer can be efficiently restored after experiencing substantial catastrophic damage. As a result, the luminescent performance of the self-healable EL devices is well recovered with a high healing efficiency (83.2% for 10 healing cycles at unfixed spots, and 57.7% for 20 healing cycles at a fixed spot). In addition, inter-device healing has also been developed to realize a conceptual “LEGO”-like assembly process at the device level for light-emitting devices. The design and realization of the self-healable EL devices may revive their performance and expand their lifetime even after undergoing a deadly cut. Our self-healable EL devices may serve as model systems for electroluminescent applications of the recently developed ionically conductive healable hydrogels and dielectric polymers.

Electroluminescence: Self-healing electroluminescent devices

Inspired by the self-healing abilities of biological systems, scientists have developed an electroluminescent (EL) device that heals itself after being damaged, paving the way for a range of new applications. Although EL devices are used in a wide range of electronic applications, including backlights for the control panels, digital displays, and wearable electronics, they are prone to damage, which restricts their working life and reliability, limiting their applications. Now, Chunyi Zhi and colleagues from the City University of Hong Kong have developed the first self-healing EL device by using a modified self-healable polyacrylic acid hydrogel for electrodes and self-healable polyurethane as a phosphor host. Even after experiencing dozens of catastrophic damages, the physiochemical properties of the device can be restored and could be used in new applications, such as healable hydrogels and dielectric polymers.