Fig. 5: Controlling omnidirectional EL of electroluminescent metasurfaces made by concentric bull’s-eye nano-OLED pixels.
From: Scalable nanopatterning of organic light-emitting diodes beyond the diffraction limit
a,d, SEM images of 1D concentric bull’s-eye nanopatterned EML with p values of 300 nm (a) and 250 nm (d). b,e, BFP images for the PL of nanopatterned EML (left) and device EL (right) of the bull’s-eye patterns in a (b) and d (e), showing radiation patterns independent of the azimuthal angle. The EL radiation patterns reveal that tuning the bull’s-eye periodicity redirects emission to different polar angles θ. c,f, Polar plots for the angular dependence of EL intensity extracted from the vertical (purple) and horizontal (yellow) cuts in the BFP images of the patterns in a (c) and d (f). The cuts are corrected by the cosθ apodization factor and compared with the Lambertian profiles (black).
