Synthesis of diimidazolylstilbenes as n-type blue fluorophores: alternative dopant materials for highly efficient electroluminescent devices.

Two new n-type diimidazolylstilbenes as blue-fluorescent dopant materials are synthesized and characterized. Blue-fluorescent devices based on these two compounds as the dopants reveal outstanding external quantum efficiencies (EQEs) (current efficiencies) of 7.8% (10.4 cd A(-1) ) and 7.7% (7.9 cd A(-1) ) with Commission internationale de l'Eclairage (CIE) co-ordinates of (0.14, 0.15) and (0.15, 0.11).