Effect of Argon Annealing Treatment on Photoelectric Properties of GZO Films Deposited by Atomic Layer Deposition

Gallium-doped zinc oxide (GZO) thin films with (100) preferred orientation were prepared on SiO2/Si substrates by atomic layer deposition (ALD). Effects of argon annealing temperature on GZO thin films were systematically investigated by X-ray diffraction (XRD), scanning electron spectroscopy (SEM), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), and Hall-effect measurement. XRD analysis showed that as the annealing temperature increased from 450 to 850 degrees C, the crystallization performance was greatly enhanced with the crystallite size of the film increasing from 35 to 65 nm. PL results revealed that the emission of oxygen vacancies in the annealed films was gradually reduced except for the film annealed at 850 degrees C, which was consistent with the decrease in concentration of oxygen vacancies deduced from XPS measurement. In addition, the resistivity of the annealed GZO films exhibited a noticeable increase up to 3 orders of magnitude. Results demonstrate that the annealing treatment process can obtain high-quality GZO films. This work lays the foundation for practical applications of ALD-GZO films including but not limited to photoelectric, transparent electronic devices.