OLED pixel smaller than a human hair may enable wearable displays

Researchers at Julius-Maximilians-Universität Würzburg have developed the world’s smallest light-emitting OLED pixel, measuring just 300 by 300 nanometers—thinner than a human hair. This breakthrough overcomes previous miniaturization limits caused by the wavelength of emitted light, using optical antennas and a metallic contact that injects current while amplifying light. The pixel’s brightness matches that of conventional OLED pixels much larger in size, enabling the potential to fit a full 1080p display within a single square millimeter. This advancement could revolutionize wearable displays by allowing ultra-compact, high-resolution screens integrated directly into eyeglass arms or even contact lenses. The team addressed technical challenges such as uneven current distribution and short-circuiting by adding a custom insulation layer with a 200-nanometer opening, ensuring pixel stability for at least two weeks under ambient conditions. While current efficiency is around 1%, researchers aim to improve this and expand the color range to full RGB. The