“…It is interesting to note that the anodized film, even without heat treatment, already exhibits high crystallinity; this fact occurs because the film was grown in such a way that electrolytic breakdown occurred, therefore generating sparks on the surface of the growing film due to the enormous increase in local temperature, thus inducing an increase in crystallinity. [24][25][26] Fig. 2c shows the Tauc plot for indirect bandgap that does not present significant changes in the bandgap value due to the treatment applied, which is consistent with the literature although slightly lower, 3.4 eV.…”