AZO/Au/AZO tri-layer thin films for the very low resistivity transparent electrode applications

• High-quality Al-doped ZnO (AZO)/Au/AZO transparent conducting oxide films.
• AZO films (30 nm) made by RF sputtering; ion sputtering for Au film (5–20 nm).
• Effects of Au thickness on optical and electrical properties were analyzed.
• The resistivity of 9 × 10−5 Ω cm and the transmittance of 86.2% of the multilayer films were obtained in this study.

Aluminum-doped ZnO (AZO)/gold/AZO tri-layer structures with very low resistivity and high transmittance are prepared by simultaneous RF magnetron sputtering (for AZO) and ion sputtering (for Au). The properties of the tri-layer films are investigated at different Au layer thicknesses (5–20 nm). The effects of Au layer thickness and the role of Au on the transmission properties of the tri-layer films were investigated. The very low resistivity of 1.01 × 10−5 Ω cm, mobility of 27.665 cm2 V−1 s−1, and carrier concentration of 4.563 × 1022 cm−3 were obtained at an Au layer thickness of 20 nm. The peak transmittance of 86.18% at 650-nm wavelength was obtained at an Au layer thickness of 8 nm. These results show the films to be a good candidate for high-quality electrode scheme in various display applications.