Dual-Microcavity Technology for Red, Green, and Blue Electroluminescent Devices

Microcavity structures are used in inorganic-, organic-, quantum-dot-, and perovskite-based electroluminescent (EL) devices to advance next-generation displays. However, there are difficulties in controlling electrical characteristics and patterning processes for producing different thicknesses for each red, green, and blue (RGB) subpixel, and the issues are more challenging in the high-resolution display for future realistic media. Here, a novel design method is presented for a dual-microcavity structure that controls high-order modes of a second cavity stacked on top of EL devices with the same cavity length for each subpixel to produce multiple peaks at RGB resonant wavelengths. The dual-microcavity effect demonstrated by top-emitting organic light-emitting diodes (OLEDs) can be conveniently fabricated via in situ deposition. By modulating the high-order modes, the spectral characteristics of each RGB dual-microcavity top-emitting OLED (DMTOLED) are manipulated while its electrical properties are maintained. Green DMTOLED exhibits a maximum luminance of 2.075 × 10⁵ cd m⁻², allowing applications not only for commercialized displays but also for outdoor augmented reality and automotive displays. Furthermore, dual-microcavity structures with narrow spectral bandwidths can be applied to next-generation EL devices for more realistic media. The method is expected to be applied industrially, promoting the advancement of EL devices for next-generation displays.