Dependence of the current and power efficiencies of organic light-emittingdiode on the thickness of the constituent organic layers

The dependence of the current and power efficiencies of bi-layer organic li ght-emitting diodes (OLEDs) on the thickness of the constituent organic lay ers is reported. The thickness of the electron and hole transport layers wa s simultaneously varied to determine the optimal configuration for power ef ficiency. It was verified that the inclusion of a suitable electrode buffer layer reduced the effective energy barrier against carrier injection, thus improved the injection efficiency. An optimal thickness for the electrode buffer layer was also identified and explained.