A high performance inverted organic light emitting diode using an electron transporting material with low energy barrier for electron injection

A high performance inverted green emission organic light emitting diode with a maximum external quantum efficiency of 20% and a maximum power efficiency of 80 lm/W was realized by properly selecting an electron transporting material to have no energy barrier for electron injection between the n-doped electron transporting layer (n-ETL) and the ETL. Based on the energy levels and the current density–voltage characteristics of electron only devices, we demonstrate that the interface between an n-ETL and an ETL even in homo-junction is as important as the interface between the cathode and the n-ETL for efficient electron injection into an emitting layer.

Graphical abstract.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A high performance inverted OLED for flexible electronics is demonstrated. ► Efficient electron injection from ITO was achieved by using n-doping of electron transporting layer. ► Low energy barrier at the n-ETL/undoped ETL interface is important for efficient electron injection.