Simple excited-state modification toward a deep-blue hybridized local and charge-transfer (HLCT) fluorophore and non-doped organic light-emitting diodes

Realizing high-performance deep-blue fluorophores and non-doped organic light-emitting diodes (OLEDs) with the Commission International de I'Eclairage (CIE) coordinates of CIEy < 0.046 is an important and challenging task for wide color-gamut displays. In this work, we report an efficient deep-blue hybridized local and charge-transfer (HLCT) fluorescent material with considerable fluorescence quantum yield and bipolar-transporting characteristics by managing the excited state and charge-transporting properties via a simple and novel acceptor p-difluorobenzene. The resulting non-doped OLED not only shows a high external quantum efficiency of 5.62%, but also exhibits stable deep-blue emission with the CIE coordinates of (0.163, 0.035) and a narrow full-width at half-maximum of 50 nm. This should be one of the state-of-the-art efficiencies achieved in the non-doped OLEDs with a CIEy of less than 0.046.