Scientists have built a pixel measuring just 300 nanometres across that could shrink augmented reality displays to the point where entire high-definition screens fit on areas smaller than a pinhead, according to researchers at Julius-Maximilians-Universität Würzburg.
The breakthrough combines optical antennas with organic light-emitting diodes to create pixels as bright as those in conventional displays, despite being dramatically smaller. A full 1920×1080 HD display using this technology would occupy just one square millimetre — small enough to embed in eyeglass frames or even contact lenses, the team claims in Science Advances.
Traditional OLED pixels measure around five micrometres across, limiting how compact displays can become. The Würzburg team’s nano-pixel achieves the same brightness at 300×300 nanometres — roughly one-seventeenth the width — using a gold antenna structure that amplifies and emits light from organic molecules, according to the researchers.
“With the help of a metallic contact that allows current injection into an organic light-emitting diode while simultaneously amplifying and emitting the generated light, we have created a pixel for orange light,” said Bert Hecht, who led the research alongside Jens Pflaum.
Currents concentrate at corners
The miniaturisation challenge centred on controlling electrical currents at nanoscale dimensions. Simply shrinking conventional OLED designs causes currents to concentrate at corners like electricity gathering at lightning rods, creating destructive gold filaments that short-circuit the device, the physicists explain.
Researchers say they solved this by adding an insulation layer atop the optical antenna with a circular 200-nanometre opening at its centre. This design blocks edge currents whilst enabling stable operation—the first prototypes ran continuously for two weeks under ambient conditions without degradation, they report.
The technology currently produces orange light at one per cent efficiency. Future development aims to boost efficiency and expand the colour range to full RGB spectrum, enabling complete miniature displays for augmented reality applications, according to the team.
Smart glasses have long promised to overlay digital information directly onto users’ vision but remained bulky due to display limitations. Current AR headsets require large optical systems to project images, making them conspicuous and uncomfortable for extended wear.
Nanoscale pixels could integrate displays directly into eyeglass arms, projecting images onto lenses without visible hardware, the researchers suggest. The extreme miniaturisation opens possibilities beyond current AR concepts—displays small enough for contact lenses or other body-worn devices previously considered impossible.
OLEDs generate light when electrical current causes electrons and holes to recombine in organic material layers, exciting molecules that release photons. Each pixel produces its own light without backlighting, enabling deep blacks and vivid colours whilst maintaining energy efficiency crucial for portable devices.
The Würzburg team claims their approach represents a fundamental shift from classical optics, which typically cannot produce efficient light-emitting pixels smaller than the wavelength of emitted light. Their optical antenna design overcomes this limitation through electromagnetic field enhancement at the nanoscale, they say.
