Optimized efficiency and angular emission characteristics of white top-emitting organic electroluminescent diodes

The concept of an additional capping layer, which is deposited onto the semitransparent top contact, is applied to minimize microcavity effects for white light emission from top-emitting organic light emitting devices (OLEDs). The influence on the optical properties of such devices with silver as top electrode material is discussed using an analytical method and numerical simulations. The results of the theoretical findings are experimentally verified for inverted top emitting devices on opaque substrates, showing broad spectral bandwidth and angle-independent color coordinates.