Technical status of top-emission organic light-emitting diodes

Top-emission organic light-emitting diodes (TEOLEDs) that contain semi-transparent metal top cathodes and highly reflective anodes have been actively researched for display applications due to their many advantages such as their high aperture ratio, good color purity, and high efficiency. In this research, the technical design of TEOLEDs used in organic light-emitting diode (OLED) displays is reviewed, covering the optical theory with the microcavity effect, optical losses, and the importance of the Purcell effect in the optical calculation. The key methodologies for addressing the high efficiency and low driving voltage of TEOLEDs are also discussed.