Seoul National University and Cambridge teams achieve 21.9% efficiency, paving way for high-resolution AR/VR displays

By Kwak Soo-keun

Published 2026.07.09. 00:37

The English acronym of Seoul National University, 'SNU', is realized using perovskite LED. The photo on the right shows it not turning off even when bent. /Seoul National University

A next-generation light-emitting device technology has been developed to succeed organic light-emitting diodes (OLEDs), which have become mainstream in smartphones and high-end TV screens. Since it uses the same thin-film stacking method in a vacuum as existing OLED processes, it is expected to be applied to the development of smaller and sharper augmented reality (AR) and virtual reality (VR) displays.

A joint research team led by Professor Lee Tae-woo from the Department of Materials Science and Engineering at Seoul National University and Professor Samuel Stranks from the University of Cambridge recently announced in the international journal *Nature Nanotechnology* that they achieved world-leading efficiency by fabricating perovskite light-emitting diodes (PeLEDs) using a vacuum deposition method.

Perovskite is considered a next-generation display candidate after OLEDs due to its vivid colors and high luminous efficiency. In particular, devices like AR glasses or VR headsets, which project tiny screens directly in front of the eyes, require bright and densely packed pixels. If perovskite LEDs are commercialized, ultra-high-resolution displays that remain visible under sunlight and clearly render small text could be realized.

Until now, high-efficiency perovskite LEDs were primarily made by dissolving raw materials in liquid and coating them onto substrates. However, this method has limitations in precisely creating tiny pixels or uniformly applying the light-emitting layer over large substrates. The research team developed a new organic molecule to fabricate perovskite via vacuum deposition, similar to OLEDs. This molecule guided the growth direction of perovskite crystals to prevent random formation. Additionally, the team ensured that perovskite crystals grew uniformly across the entire surface instead of clumping in specific areas. The external quantum efficiency of the resulting perovskite LED reached a maximum of 21.9 percent. External quantum efficiency is a key metric indicating how effectively electrons injected into the device produce light that escapes. The team stated that this is the highest level achieved for vacuum-deposited perovskite LEDs.

The lifespan was also significantly extended, taking over 1,500 minutes for the initial brightness to halve. However, to apply this technology to actual smartphones, TVs, or AR devices, the lifespan must be further increased to thousands or tens of thousands of hours.

The team demonstrated the "SNU" pattern, the English acronym for Seoul National University, on a 7×7 cm substrate and also created light-emitting devices on a flexible substrate. This work is evaluated as showing potential for scaling up to large-area and flexible displays beyond small experimental devices.