Determination of internal quantum efficiency of OLEDs with the consideration of the Purcell effect

Abstract

Organic light-emitting devices (OLEDs) with various device configurations have been the subjects of intensive research due to their applications in display and lighting [1-4]. Considering the microcavity effect, OLEDs can be roughly categorized into two types, i.e., weak microcavity OLEDs and strong microcavity OLEDs. Conventional bottom emitting OLEDs are weak microcavity devices while OLEDs with distributed Bragg reflectors or two metallic electrodes are considered as strong microcavity devices. Light emission properties, including the internal quantum efficiency (IQE), external quantum efficiency, exciton lifetime and angular dependence, are distinct in the two types of OLEDs due to the Purcell effect [5-8].