Improved light extraction efficiency of white organic light-emitting devices by biomimetic antireflective surfaces

One simple method to increase the light extraction from white organic light-emitting devices by using biomimetic silica antireflective surfaces is demonstrated. A silica cone array was directly etched on the opposite side of the indium–tin–oxide coated fused silica substrate. The antireflective surfaces can dramatically suppress the reflection loss and increase the transmission of light over a large range of wavelength and a large field of view. Using such surfaces, the luminance efficiency of the device in the normal direction is increased by a factor of 1.4 compared to that of the device using flat silica substrate.