-We succeeded in developing a single-unit hybrid organic light-emitting diode (OLED) device with efficient light emission from both a phosphorescent layer and a fluorescent layer. The single-unit hybrid OLED achieved a power efficiency higher than that of a two-unit hybrid tandem OLED with phosphorescent and fluorescent layers.

This paper discusses the effectiveness of energy transfer from an exciplex to an emitter in both phosphorescent and fluorescent organic light‐emitting diodes. This energy transfer enhances the efficiency, lowers the drive voltage, and extends the lifetime. The increase in the quantum efficiency of a fluorescent organic light‐emitting diode using this mechanism is also analyzed.

Efficient energy transfer from an exciplex to a phosphorescent dopant was successfully introduced to a blue phosphorescent organic light-emitting diode by carefully designing the exciplex and dopant. This energy transfer simultaneously achieved increase in quantum efficiency, decrease in driving voltage, and improvement in lifetime even in blue devices.

We succeeded in developing a single‐unit hybrid organic light‐emitting diode (OLED) device with efficient light emission from both a phosphorescent layer and a fluorescent layer. The single‐unit hybrid OLED achieved power efficiency higher than that of a two‐unit hybrid tandem OLED with a phosphorescent and fluorescent layers.

This paper discusses the effectiveness of energy transfer from an exciplex to an emitter in both phosphorescent and fluorescent OLEDs. This energy transfer enhances the efficiency, lowers the drive voltage, and extends the lifetime. The increase in the quantum efficiency of a fluorescent OLED using this mechanism is also analyzed.