The effects of tris(2-phenylpyridine) iridium on the hole injection and transport properties of 4,4′,4″-tri(N-carbazolyl)-triphenylamine thin films

► Electronic properties of 4,4′,4″-tri (N-carbazolyl)-triphenylamine(TCTA) are studied. ► Tris(2-phenylpyridine) iridium[Ir(ppy)3] affects the charge properties in TCTA. ► Ir(ppy)3 can enhance the hole injection properties from indium-tin-oxide to TCTA. ► Hole mobility varies with the doping concentration in the TCTA:Ir(ppy)3 system.