. 2021 Jan 21;6(4):2665–2674. doi: 10.1021/acsomega.0c04837

Table 2. Optical Band Gap Energy and Phase Identification Evidenced from XRD and Raman Spectra for the As-Grown and Annealed Samples Deposited at Different Temperatures Using IPA^a.

glass samples	bandgap, E_g (eV) ± 0.01	Cu foil samples	bandgap, E_g (eV) ± 0.01	phase composition (XRD and Raman)
G4(IPA30)	3.48	C4(IPA30)	3.47	ZnO
G5(IPA50)	3.37	C5(IPA50)	3.43	ZnO
G6(IPA65)	3.40	C6(IPA65)	3.45	ZnO
G4 Ann. 250 °C	3.28	C4 Ann. 250 °C	1.65 & 3.21	Cu_xO/ZnO
G5 Ann. 250 °C	3.21	C5 Ann. 250 °C	1.65 & 2.98	Cu_xO/ZnO
G6 Ann. 250 °C	3.15	C6 Ann. 250 °C	2.00 & 3.00	Cu_xO/ZnO

Crystallite sizes of the samples grown on the SLG substrate are shown in Table 1.

Table 2. Optical Band Gap Energy and Phase Identification Evidenced from XRD and Raman Spectra for the As-Grown and Annealed Samples Deposited at Different Temperatures Using IPAa.