In-plane electroluminescence from microcavity organic light-emitting transistors

Abstract We report the observation of in-plane emission beneath the drain electrode in multilayer heterostructure organic light-emitting transistors (OLETs). A novel modification method for the interface between the hole transport layer and the emission layer has been proposed, which brought a great enhancement for the light power and external quantum efficiency. Further, distributed Bragg reflector was incorporated to the in-plane-emitted OLETs, which combined with the top thin layer of Au, forming a vertical microcavity. The electroluminescence spectra were significantly altered by the microcavity and much narrower linewidth was obtained. The results will help to develop high color purity and white OLETs with high performance, which would be useful for multifunctional displays.