*3.2. E*ff*ects of Annealing Temperature on Structural Properties of Ti:SnO2 Films*

Figure 1 shows the XRD patterns of the as-deposited and annealed Ti:SnO2 thin films. As the annealing temperature increases, prominent peaks are observed at 26.6◦, 33.8◦, and 51.7◦ corresponding to (110), (101), and (211) phases, respectively. The (101) phase is a combined SnO and SnO2 phase [27]; some of the Sn and Ti atoms are replaced by a diffused process following the annealing process [28,29]. Notably, diffraction peaks are very small in the as-deposited film or the film annealed at 200 ◦C. However, as the annealing temperature increases to 300 ◦C, the crystalline phase appears more within the film. The crystalline structure becomes increasingly pronounced as the annealing temperature increases to 500 ◦C, and hence has a significant effect on the electrical and optical properties, as described in the following sections.

**Figure 1.** X-ray diffraction (XRD) patterns of as-deposited and annealed Ti:SnO2 films.
