Researchers developed the world's smallest OLED device at 100 nm, for super-resolution imaging and chiplet communication

Researchers from ETH Zurich, in collaboration with colleagues from the Indian Institute of Science and the University of Alberta, developed a new method to fabricate nanoscale OLED devices - with pixel size of only 100 nm. This goes below the diffraction limit of the emission wavelength, which can be highly useful for both super-resolution imaging and on-chip light sources for ultrabroadband chip-to-chip (chiplet) communication. 

The researchers created a display with a pixel pitch of 250 nm - or 100,000 PPI (!). The process achieves the direct nanoscale patterning of organic semiconductors by self-aligned nanostencil etching and lithography. The process is resist-free and involves etching and evaporation through nanoapertures in a free-standing film adhering to the substrate. 

The researchers report that the fabricated nanoscale OLED device, that has over 1 megapixels, exhibits an average EQE of 13.1%. The researchers also demonstrate electroluminescent metasurfaces with subwavelength-scale meta-atoms that can electrically modulate the emitted light. The diffractive coupling between nanopixels enables control over the far-field emission properties of light, including directionality and polarization.

This interesting research arrives only a few days after a paper from the Julius-Maximilians-Universität Würzburg (JMU), in which the researchers reported on the deposition of the world's smallest OLED to date, at 300 x 300 nm. To create such small pixels, the researchers developed a novel metallic contact that allows current injection into the OLED while simultaneously amplifying and emitting the generated light.