The researchers have developed extremely small organic light-emitting diodes, so-called nano-OLEDs. These are so tiny that 100 can fit next to each other in the diameter of a human cell, ETH Zurich announced on Monday.

Today, OLEDs are mainly used in high-quality smartphones and television screens. However, according to ETH Zurich, the newly developed nano-OLEDs are up to 50 times smaller than previous OLED pixels. This means that pixels can be arranged much more densely than with the previous technology.

Pixels in the size range of 100 to 200 nanometres lay the foundation for ultra-high-resolution screens, which could display razor-sharp images in glasses close to the eye, for example. They also open up new possibilities in microscopy. As a light source, nano-OLEDs could illuminate the smallest areas in a targeted manner and thus enable particularly detailed images. The researchers also see potential for applications in medical technology, such as biosensors that can detect the signals of individual nerve cells.

According to ETH Zurich, because the pixels are smaller than the wavelength of visible light, optical effects can also be used in a targeted manner to focus or direct light – for example for new types of mini-laser or holographic images.

The researchers produced the new light-emitting diodes using a specially developed process that enables the extremely precise placement of certain molecules. Ultra-thin ceramic membranes made of silicon nitride are used as templates and allow unprecedented miniaturisation in a single manufacturing step.

They presented the new OLEDs to experts in a study published in the journal Nature Photonics.

Adapted from French by DeepL/sb