Figure 5

(a) absorption spectra for the CGO thin films synthesized at different condition. Tauc plots of according samples by (b) direct \((\mathrm{n}=1/2)\), and (c) indirect \((\mathrm{n}=2)\) bandgap consideration. All the fittings are exerted in linear ranges of the plots by OriginLab software. At the inset a schematic curve illustrates the conceptualized band structure for α-CGO and some main electron transitions with different energy distance.