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

The dependence of the current and power efficiencies of bi-layer organic light-emitting diodes (OLEDs) on the thickness of the constituent organic layers is reported. The thickness of the electron and hole transport layers was simultaneously varied to determine the optimal configuration for power efficiency. 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.