Efficient Electron Injection in Organic Light Emitting Diodes with Al–Mg Alloy Cathode

Abstract
We report the enhancement of electron injection using an Al–Mg alloy cathode in organic light emitting diodes (OLEDs). The luminescence value at 15 V drastically increased from 800 to as the Al cathode was replaced by an Al–Mg alloy with a ratio of Al to Mg in weight percent. Synchrotron radiation photoelectron spectroscopy results showed that the work function of the Al–Mg alloy is lower by 0.2 eV than that of Al. Thus, the energy barrier for electron injection was lowered, reducing the turn-on voltage and increasing the quantum efficiency of OLEDs.