Hybrid white OLED

Hybrid white OLED usually consist of phosphorescent green and red emission layers, combined with a fluorescent blue emission layer. Thus, the excellent lifetime of blue fluorescent emitters can be combined with the high efficiency of phosphorescent green and red emitters. To prevent parasitic triplet exciton diffusion from the phosphorescent emission layers into the fluorescent blue emission layer, a high triplet energy interlayer can be employed.
Different concepts for such an interlayer are currently being investigated in our work group. To obtain sufficient charge transport properties for electrons and holes, a mixed interlayer consisting of a hole-transporting material and an electron-transporting material can be favorable. Furthermore, it is possible to control the color temperature of the OLED by adjusting the mixing ratio.

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Fig.: Typical hybrid stack for white OLED