| abstract |
The present invention provides a novel organic electroluminescent device having an optical interference member which reduces the overall reflectance from the device. The invention is particularly suited to current-driven organic displays having an anode, an electroluminescent layer and a cathode, where at least one optical interference member is placed between two of the layers and thus forms part of the electrical circuit required to excite the display. The optical interference member is chosen to have a thickness which causes at least some destructive optical interference of ambient light incident on the display. In addition, the material(s) of the optical interference member are chosen to have a work function which is compatible with the highest occupied molecular orbital, or the lowest unoccupied molecular orbital of the electroluminescent layer, depending on the location of the optical interference member in relation to the anode, cathode and electroluminescent layer. The appropriate selection of material can ensure proper current flow through the device, thus reducing the likelihood of electrical breakdown of the organic electroluminescent layer, and improving the overall energy efficiency of the device. |