Doped ZnO thin films as anode materials for organic light-emitting diodes

Zinc oxide thin films, doped with aluminum (AZO), gallium (GZO) and zirconium (ZZO), have been deposited on glass substrates by pulsed laser deposition. The electrical and optical properties of these films were investigated as a function of oxygen deposition pressure. These doped zinc oxide films were used as an anode contact to fabricate organic light-emitting diodes. Luminance efficiencies of 0.1 lm/W, 0.2 lm/W and 0.9 lm/W were measured at the light output of 100 cd/m(2) for the AZO, GZO and ZZO films, respectively. Doped zinc oxides are attractive alternative materials as transparent conducting electrode because they are nontoxic and inexpensive compared with indium tin oxide (ITO). (C) 2002 Elsevier Science B.V. All rights reserved.