Improvement of current efficiency at high field regime via description of roll-off characteristic in model device of OLEDs

We demonstrated the effect of the field dependency of charge carrier mobility on roll-off characteristic of current efficiency. Field dependent factor in Poole-Frenkel model is controlled to describe charge balance of electron and hole concentration at high field. It is well established that roll-off characteristic is dependent upon mobility match which results in charge balance in EML. We exhibited the improvement of the roll-off characteristic of current efficiency and explained how charge balance is induced through this description.