Locally twisted donor-p-acceptor fluorophore based on phenanthroimidazole-phenoxazine hybrid for electroluminescence

A new phenanthroimidazole-based emitter with an electron-rich phenoxazine (PIPXZ) for electrolumi-nescence is developed. The introduction of phenoxazine to the phenanthroimidazole motif results in a locally twisted donor-pi-acceptor conformation. The unique molecular structure endows the new material with an intense charge-transfer excited state and good fluorescence efficiency. The new emitter PIPXZ is systematically investigated by absorption/emission spectroscopy, thermoanalysis, density functional theory calculation, etc. PIPXZ is successfully applied in organic light-emitting device (OLED) as the emitting layer, emitting sky-blue EL with an external quantum efficiency of 1.79% at 10 0 0 cd m-2. This study may offer a guideline for designing charge-transfer blue emitters for OLEDs (C) 2022 Published by Elsevier B.V.

Automated summary

A new phenanthroimidazole-based emitter with an electron-rich phenoxazine (PIPXZ) has been developed, which possesses a locally twisted donor-pi-acceptor conformation due to the introduction of phenoxazine. The unique molecular structure of PIPXZ leads to an intense charge-transfer excited state and good fluorescence efficiency. The emitter has been systematically investigated and successfully applied in an organic light-emitting device, demonstrating a high external quantum efficiency.