Electro-optic properties of double-type emission of organic electroluminescence device

Abstract

We study electroluminescence and impedance properties of a double-type white organic light-emitting device (WOLED) based on phosphorescent and thermally activated delayed fluorescence emissions in a single heterostructure. Current-voltage characteristics of the WOLED and impedance spectroscopy data are obtained for the layered and composite-layer devices. These results demonstrate that a combination of layer-based and composite-based technologies in a single heterostructure improves both the efficiency and the stability of WOLED heterostructures. Light-emission performance of the WOLED is also studied. The device reveals very good electroluminescence properties and colour coordinates as a white light source. Its maximal brightness is larger than 10 4 cd/m 2 and the maximal external quantum efficiency is larger than 12%.