Supplemental Figure 1, Supplemental Figure 2, Supplemental Table 3, Supplemental Figure 4, Supplemental Figure 5

Fig. S1. θ-2θ XRD pattern of the GeO2 deposited at 600 {degree sign}C on the GSO/TiO2 (001); Fig. S2. θ-2θ XRD patterns of the r-GeO2 thin films crystallized without the plasma activation of O2 gas; Table S3. Thickness of the GeO2 layer before and after crystallization; Fig. S4. Raman spectrum of the amorphous GeO2 layer; Fig. S5. θ-2θ XRD patterns and rocking curves of the GSO seed layer after the post deposition annealing