Efficient deep blue emitter based on carbazole-pyrene hybrid for non-doped electroluminescent device

A new deep blue fluorescent material based on carbazole-pyrene hybrid, namely PyEtCz, was synthesized by palladium catalyzed C-C Suzuki coupling reaction, and structurally characterized by NMR, mass spectra and elemental analysis. The thermal stability, photophysical and optoelectronic properties were fully investigated. The material shows good thermal stability and can form an amorphous glass state. Its CH2Cl2 solution exhibits strong deep-blue emission with high fluorescent quantum yield of 75%. PyEtCz also possesses high HOMO level of -5.48 eV that would facilitate efficient hole injection into the emitting layer. The non-doped OLED using PyEtCz as emitter through vacuum evaporation was fabricated for purpose of investigating its electroluminescence properties. The device exhibited stable blue electroluminescence with CIE coordinate of (0.15, 0.10), a good performance with maximum luminance of 6573 cd m(-2) and maximum luminance efficiency of 3.24 cd A(-1) (3.35%) was achieved.