We propose and demonstrate weak-microcavity organic light-emitting diode (OLED) displays that deliver both a high
light-extraction efficiency and wide viewing-angle characteristics. A single pair of low- and high-index layers is
inserted between indium tin oxide (ITO) and a glass substrate. The electroluminescent (EL) efficiencies of discrete red,
green, and blue weak-microcavity OLEDs (WMOLEDs) are enhanced by 56%, 107%, and 26%, respectively with
minimal changes viewing angle and EL spectra characteristics. The color purity is also improved for all three colors.
Moreover, we fabricated full-color 128×160 passive-matrix bottom-emitting WMOLED displays to prove their
manufacturability. This design is realized by simple one-step 20-nm etching of the low-index layer of red/green subpixels.
The EL efficiency of white color in the WMOLED display is 27% higher than that of a conventional OLED
We have designed channel-drop filters with two line defects and a resonance system based on the two-dimensional triangular-lattice-hole photonic-crystal structure by two-dimensional and three-dimensional finite-difference time-domain simulations. The quality factors have been calculated to be around 3,500 of a two-dimensional channel-drop filter and to be around 300 of a resonance system based on the triangular-lattice hole-based photonic-crystal slab structure.
We have developed an finite-difference time-domain program that can analyze photonic devices with gain and/or dispersion. As an example, a two-dimensional photonic-crystal laser is simulated. The simulation can show the relaxation oscillation behavior at extremely high current injection.