Effects of annealing atmosphere on microstructure and photoelectric properties of titanium-doped ZnO nanofilms

In this research, four titanium-doped zinc oxide (TZO) thin films were deposited on quartz glass substrates by radio frequency (RF) magnetron sputtering. Three of the samples were annealed at 4 0 0 ∘ C for 40 mins in N 2 , Ar and vacuum, respectively. The microstructure and photoelectric properties of the films were characterized. The results showed that annealing in different atmospheres has a significant effect on the microstructure and photoelectric properties. The structure of all the annealed films remained polycrystalline, with a c -axis preferred orientation, and the crystallization quality was improved. In addition, the photoelectric properties were also significantly improved by annealing with the average transmittance in the visible region exceeding 90%, the resistivity reaching 3 . 3 2 × 1 0 − 4 Ω ⋅ cm . The conductivity enhancement was mainly attributed to the increased mobility of carriers. Annealing in argon had the best effect. Finally, the resistivity of all the samples experienced an initial negligible change followed by an increase as the temperature was raised from 10 to 350 K.