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

## TL;DR

Researchers developed a method to create large, flexible light-emitting devices using aerosol spraying, achieving high brightness and stability for use in drone navigation.

## Contribution

A simple aerosol spraying method with modified ink enables large-scale flexible electroluminescent devices with high brightness and stability.

## Key findings

- The method achieved a maximum brightness of nearly 500 cd·m−2 in small devices.
- A 1.2 m × 1.2 m ultra-large device reached 303.3 cd·m−2 brightness.
- Devices showed excellent stability in high-temperature, humid, and water-rich environments.

## Abstract

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.

This work presents a simple aerosol spraying method using modified luminescent ink to fabricate meter‐scale flexible alternating current electroluminescent (ACEL) devices. Enhanced particle dispersibility and film uniformity yield impressive brightness up to 500 cd m−2, positioning these devices as effective luminous navigation signs for industrial drones.