A Study on the Structure and the Photoelectrical Properties of the Al-Doped ZnO Thin Films by Atomic Layer Deposition in Low Temperatures

The AZO transparent conductive films are prepared by the atomic layer deposition (ALD) at a low temperature of 150 °C. The different Al–Zn doping ratios were designed during the deposition. The phase structure of the films was characterized by XRD, the electrical properties of thin films were analyzed by the Holzer test, and the optical properties of thin films were analyzed by the UV-3600 (UV-VIS-NIR) spectrophotometer. The results showed that all the films preferred the orientation of the C axis during the growth process, the AZO films have a very low resistivity of 6.955×10⁻⁴ Ω·cm with the Al doping ratio by 2%, the deposition temperature is 150 °C and the thickness of the film is 200 nm. The transmission of AZO films with the different doping ratios in the visible region is 85%. The proper doping ratio can be selected to get the excellent photoelectric properties of AZO thin films. Such low resistivity AZO transparent conductive film is expected to replace the ITO as the transparent electrode for the organic light-emitting devices and the other new generation of the optoelectronic devices.