Effect of aluminum doping on zinc oxide thin films grown by pulsed laser deposition for organic light-emitting devices

• Published in: Thin solid films 2000-12, Vol.377, p.798-802
• Main Authors: Kim, H, Piqué, A, Horwitz, J.S, Murata, H, Kafafi, Z.H, Gilmore, C.M, Chrisey, D.B
• Format: Article
• Language: English
• Subjects: Aluminum doped zinc oxide (AZO); Organic light emitting diodes (OLEDs); Pulsed laser deposition (PLD); Transparent conducting oxide (TCO)
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/S0040-6090(00)01290-6

Transparent conducting aluminum-doped zinc oxide (AZO) thin films have been deposited on glass substrates by pulsed laser deposition. The structural, electrical and optical properties of these films were investigated as a function of Al-doping amount (0–4 wt.%) in the target. Films were deposited at a substrate temperature of 200°C in 0.67 Pa of oxygen pressure. It was observed that 0.8-wt.% of Al is the optimum doping amount in the target to achieve the minimum film resistivity and the maximum film transmission. For the 300-nm thick AZO film deposited using a ZnO target with an Al content of 0.8 wt.%, the electrical resistivity was 3.7×10 −4 Ω-cm and the average transmission in the visible range (400–700 nm) was 90%. The AZO films grown by PLD were used as transparent anodes to fabricate organic light-emitting diodes. The device performance was measured and an external quantum efficiency of 0.3% was measured at a current density of 100 A/m 2.