Meter-Scale Ultra-Large-Area Flexible Electroluminescent Devices Enabled by Aerosol Spraying

Flexible alternating current electroluminescent (ACEL) devices have garnered significant research interest due to their potential applications in illumination and display. However, challenges remain in fabricating ACEL devices with high brightness and excellent working stability over a large luminescent area. In this study, we demonstrate a simple aerosol spraying method with modified luminescent ink to fabricate meter-scale flexible ACEL devices. In the fabrication process, the particle dispersibility of luminescent ink and the uniformity of sprayed film have been significantly improved. This improvement is primarily attributed to the introduction of long-chain molecular groups of the surfactant, which can bind to the surface of ZnS:Cu luminescent particles at one end, while the other end remains suspended in the oily solvent, providing substantial steric hindrance. The fabricated planar thin-film ACEL devices demonstrated excellent substrate compatibility and flexibility, with exceptional operational stability in high-temperature, humid, and water-rich environments. Remarkably, we achieved a maximum brightness of nearly 500 cd·m^-2 in small-sized devices, while a brightness of 303.3 cd m^-2 from an ultra-large device of 1.2 m × 1.2 m. These devices have been further explored as navigation signs for autonomous takeoff and landing of industry drones.