Low-temperature nickel-doped indium tin oxide anode for flexible organic light-emitting devices

Characteristics of an organic light-emitting diode (OLED) with a structure of Al/tris(8-hydroxyquinoline) aluminum (Alq3), N,N′-bis-(1-naphthyl)-N,N′-diphenyl-1, 1′biphenyl-4, 4′-diamine(NPB)/indium tin oxide (ITO)/Arton film have been improved by the introduction of Ni atoms in the ITO surface layer. The threshold voltage and turn-on voltage of an OLED device with Ni sputter power of 90 W and ITO surface oxygen plasma treatment can be reduced, respectively, by 3.4 V and 2.6 V. The existence of Ni atoms and the formation of Ni oxide phases on ITO surface are suggested for the improved characteristics.