| 초록 |
Trap assisted recombination has been known as the dominant mechanism in phosphorescent dye doped OLEDs because of the large difference in band gap between host and dopant materials to keep the triplet energy of the host higher than the dopant. Recently, however, Langevin recombination is dominant in an exciplex forming co-host without clear explanation of the reason(s). In this presentation, we show through the drift-diffusion model that the Langevin dominant recombination followed by the energy transfer originates from the balanced high electron and hole density coming from the reduced electron and hole mobility in the exciplex co-host system combined with shallow trap depth. In contrast, a single host system resulted in trap assisted recombination as expected. |
