High-contrast top-emitting organic light-emitting devices for active-matrix displays

Unlike previous high-contrast devices that all involve inserting extra layer(s) with optical purposes (e.g., absorption and interference) into the active region of devices, in this-letter we report a high-contrast top-emitting organic light-emitting device (OLED) that utilizes only optical characteristics of electrodes and anti-reflection coatings deposited outside the active region, thus reducing the complexity of devices. Furthermore, the device has an inherent microcavity which is beneficial to electroluminescence efficiency. The devices are readily compatible with the processing of active-matrix backplanes, and active-matrix OLED displays incorporating such high-contrast top-emitting devices were demonstrated to have improved readability under a strong lighting environment. (C) 2005 American Institute of Physics.