Sky-blue OLED through PVK:[Ir(Fppy)2(Mepic)] active layer

- Photophysics of [Ir(Fppy)2(Mepic)] as a guest in a PVK host matrix.
- Fabrication and characterization of a sky-blue OLED.
- Successful and feasible low-cost OLED with facile fabrication methods.

The heteroleptic [Ir(Fppy)2(Mepic)] complex exhibits an intense sky-blue phosphorescence (λmax = 474 nm; CIE color coordinates: x = 0.14 and y = 0.29) and a unitary quantum yield (ϕ = 0.98) in acetonitrile from a distinct triplet excited state of mixed 3MLCT/LLCT characters. [Ir(Fppy)2(Mepic)] as a guest in a poly-(9-vinylcarbazole) (PVK) host matrix leads to energy transfer from the polymer to the complex, resulting in the complex's blue emission with quenching of the PVK fluorescence. The active layer of an operational organic light-emitting diode (OLED) with PVK:[Ir(Fppy)2(Mepic)] film had its optoeletronic properties characterized by current-voltage curve and electroluminescent spectrum. The device exhibits a space-charge limited current and its illumination occurs after reaching the trap-filled limit at 35 V. This work is a successful proof of concept for a feasible low-cost sky-blue OLED with a simple architecture and fabrication methods that require non-specific instruments.

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