Pyridine and carbazole modified biphenyl as a host for blue phosphorescent organic light-emitting diodes

• Carbazole and pyridine modified high triplet energy host material.
• High triplet energy through ortho-modification of phenyl moiety.
• High quantum efficiency in blue phosphorescent organic light-emitting diodes.

A new biphenyl substituted with a carbazole unit and a pyridine unit, 9-(2′-(pyridin-3-yl)-[1,1′-biphenyl]-3-yl)-9H-carbazole, was synthesized as the host material for blue phosphorescent organic light-emitting diodes. A high triplet energy of 2.96 eV was obtained by inclusion of pyridine at ortho-position of biphenyl moietry. The new biphenyl was applied as the host material for blue phosphorescent organic light-emitting diodes and a high quantum efficiency of 18.4% was achieved.