Seoul National University Develops Nearly Invisible Electrode for Transparent OLEDs

Researchers at Seoul National University have developed a transparent electrode that is both highly conductive and nearly invisible. The breakthrough could improve transparent OLED displays, which are used in augmented reality and smart windows.

Metal mesh electrode achieves 93-99% transparency

The team, led by Professor Hong Yong-taek, created the electrode using a metal mesh fabricated with a technique called metal-vapor-desorption layer (MVDL) transfer. This method allows fine patterns to be formed directly on organic substrates without damaging them.

Specifications

• Optical transparency: 93% to 99%
• Sheet resistance: 1.1 to 4.0 Ω/sq
• Figure of merit: >10,000
• Electrode thickness: <1 micrometer

The electrode achieves optical transparency between 93% and 99%, making it almost invisible to the eye. Its sheet resistance ranges from 1.1 to 4.0 ohms per square, and the figure of merit exceeds 10,000, indicating excellent electrical performance.

The electrode is less than one micrometer thick. The team demonstrated the technology in a working transparent OLED, proving it can be integrated without harming organic layers.

The research was published in Materials Horizons as the outside front cover article. We covered earlier research on transparent conductive materials while following display technology advances.