Researchers at ETH Zurich have developed a process to manufacture OLEDs on a nanoscale. The resulting OLEDs are smaller than the wavelength of the emitted light, which allows precise control of the direction and polarization of the light. "The diameter of the most minute OLED pixels we have developed to date is in the range of 100 nm, which means they are around 50x smaller than the current state of the art," said researcher Jiwoo Oh. This ETH Zurich logo consists of 2800 nano light-emitting diodes and, at a height of 20 µm, matches the size of a human cell. A single pixel measures around 0.2 µm. Courtesy of ETH Zurich. The pixels range in size from 100 - 200 nm, which could be used in ultra-high-resolution screens within eyewear. The ETH researchers' nano-OLEDs can be positioned between 200 - 400 nm apart, depending on the color of visible light. Intelligently arranged nano-OLEDs can produce optical wave effects in which the light from neighboring pixels mutually reinforces or cancels each other out. Instead of emitting light in all directions above the chip, the researcher’s OLEDs only emit at very specific angles. The research team demonstrated that polarized light can also be generated by means of interactions. Polarized light can be used within medicine, for example, to distinguish healthy tissue from cancerous tissue. Radio and radar technologies use wavelengths ranging from millimeters to kilometers, called phase array arrangements, and allow antennas or transmitter signals to be precisely aligned and focused. These technologies could help in the optical spectrum, such as to further accelerate the transmission of information in data networks and computers. OLEDs are commonly manufactured by vapor depositing the light-emitting molecules onto silicon chips. The researchers used silicon nitride to miniaturize OLEDs. Silicon nitride forms strong, thin membranes that do not sag on surfaces, regardless of surface space. The researchers were able to produce templates for placing the nano-OLED pixels that are around 3000x thinner. The researchers plan to further miniaturize the pixels and to control them. With this technology, groups of OLEDs could potentially be bundled into meta-pixels and positioned precisely in space. This research was published in Nature (www.doi.org/10.1038/s41566-025-01785-z).