The investigation of sky-blue emitting anthracene-carbazole derivatives: Synthesis, photophysics and OLED applications

New well-defined structurally different 9,10-bis(9-hexyl-6-((E)-styryl)-9H-carbazol-3-yl)anthracene derivatives, shortly named "6a, 6b and 6c", with side groups having electron donating and withdrawing were systematically synthesized using Suzuki cross-coupling and Vilsmeier-Haack reactions. The impact of electron donating and withdrawing groups and their influence on the molecules photophysical properties has been investigated. The materials showed sky-blue emissions with high internal quantum efficiencies. Based on photophysical investigations the most promising molecule (6a) has been selected and high efficiency OLEDs with external quantum efficiency at very low current efficiency (similar to 1 mA/cm(2)) reaching 5% (doped) were obtained.