Circularly Polarized Phosphorescent Electroluminescence from Chiral Cationic Iridium(III) Isocyanide Complexes

Circularly polarized organic light-emitting diodes (CP-OLEDs), which directly emit CP light from organic light-emitting diodes, have attracted considerable attention because of their wide applications in various photonic devices. In this work, a pair of chiral bis-cyclometalated phosphorescent iridium(III) isocyanide complexes is designed and synthesized, which exhibits almost the same photophysical properties and obvious mirror image in circular dichroism spectrum. These two complexes are used for fabricating CP-OLEDs, obtaining 4473 cd m⁻², 7.50 cd A⁻¹, and 2.55 lm W⁻¹ for the maximum luminance and the maximum current and power efficiencies, respectively. In addition, the dissymmetry g_EL factors of CP emission are in the order of 10⁻³, which is the highest value among the reported devices based on phosphorescent Ir(III) complexes. The results demonstrate that the chiral Ir(III) complexes are of great potential value for application in CP-OLEDs.