Numerical analysis of the electrical and the optical properties of green phosphorescent organic light-emitting diodes

In this paper, we report a theoretical study on the electrical-optical properties of phosphorescent organic light-emitting diodes (PHOLEDs). Our simulation reveals that the refractive index of each material plays a crucial role in the emission characteristics and that the barrier height at the interface significantly influences the behavior of charge transport as well as the generation of excitons. The calculated transient profiles indicate that the carrier recombination in the PHOLEDs takes place mainly at the interface between the emitting layer and the hole transport layer after 8 μ s. In the case of high index of refraction, the simulation result via modal analysis implies a possibility for improving the light extraction by increasing the substrate mode. As the thickness of each layer has been altered, we observe that the chromaticity of the device changes periodically.