Ultrahigh-Efficiency Green PHOLEDs with a Voltage under 3 V and a Power Efficiency of Nearly 110 lm W−1 at Luminance of 10 000 cd m−2

Maintaining high power efficiency (PE) under high brightness is still a pressing problem for the practical application of organic light-emitting diodes (OLEDs). Here, ultrahigh-efficiency green phosphorescent OLEDs (PHOLEDs) with a record-low voltage at luminance above 5000 cd m⁻² are fabricated, by developing a novel anthracene/pyridine derivative as the electron-transporting material (ETM) combined with a material displaying thermally activated delayed fluorescence as the host. The pyridine units of the ETM not only facilitate charge injection, but also enhance the electron-transporting mobility, profiting from the closely packed molecules caused by the intermolecular H-bonding. The optimized green PHOLEDs show record-low driving voltages of 2.76 and 2.92 V, with EQEs/PEs of 28.0%/102 lm W⁻¹ and 27.9%/97 lm W⁻¹ at 5000 and 10 000 cd m⁻², respectively. Furthermore, device optimization exhibits an unprecedented high PE of 109 lm W⁻¹ at 10 000 cd m⁻² with voltage under 3 V. Those values are the state-of-the-art among all reported green OLEDs so far, paving their way toward practical applications.

Ultrahigh-efficiencygreen phosphorescent organic light-emitting diodes (PHOLEDs) with a voltage under 3 V and a power efficiency of nearly 110 lm W⁻¹ at a luminance of 10 000 cd m⁻² are developed by utilizing a novel anthracene/pyridine derivative as the electron-transporting material combined with a material displaying thermally activated delayed fluorescence as the host.

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