Fig. 1: Scalable fabrication of nano-OLEDs.
From: Scalable nanopatterning of organic light-emitting diodes beyond the diffraction limit
a, Cross-sectional schematic of a nanostencil in close contact with the substrate. The free-standing SiNx membrane faces the substrate, separated by an air gap of 0.5–1 µm. b, Illustration of the nano-OLED fabrication process. After spin coating the HIL and the insulation layer, a nanostencil is aligned and attached to the substrate, serving as a mask for etching and thermal evaporation of the organic nanopixels, consisting of the HTL and EML, resulting in self-aligned pixel insulation. Subsequent layers, ETL and cathode, are deposited as continuous films. c, SEM images of the nanopixels at different steps of the fabrication process. The nanostencil features a square array of circular nanoapertures with a diameter of 100 nm and a periodicity of 300 nm. d, Photograph of a nano-OLED device operating at 5.0 V (left), and the optical micrograph (middle) of a nanopixel array displaying the ‘ETH Zürich’ logo at 50,000 ppi. Each logo comprises approximately 2,800 nanopixels, and the SEM image (right) shows a part of the nanopixel array. The nanodisc OLED pixels have a diameter of 200 nm and a periodicity of 500 nm.
