Charge Injection in Organic Light Emitting Diodes Governed by Interfacial States

摘要

Charge injection in organic light emitting diodes (OLEDs) is studied by impedance spectroscopy on a solution processable polymer based OLED (PLED) using different metallic cathodes. A negative capacitance is observed in organic light-emitting diodes (OLEDs) at low frequencies which can be explained using a detailed kinetic model based on sequential injection through surface states at the metal/organic interface. In this paper the methodology used to derive this model and its application to experimental data is presented.