The Effects of Growth Time on Surface Morphology and Optical Band Gap Energy ZnO Thin Films

Abstract

All thin ZnO films are synthesized by nebulizer on silicon substrates with growth periods of 10, 20, and 30 minutes. The characterizations are performed by ultraviolet-visible (UV-Vis) spectrophotometer, scanning probe microscopy, and X-ray diffraction (XRD), the thin ZnO films with various growth durations of 10, 20, and 30 minutes have been observed. The results show that all samples have polycrystalline hexagonal wurtzite and varying root mean square (RMS) roughness levels with the average island height of 86.931 nm, 70.046 nm, and 99.623 nm for the deposition time of 10, 20, and 30 minutes, respectively. The optical band gap energy of the thin ZnO films have predicted by extrapolating the linear plot of the Tauc equation. It confirms 3.25, 3.24, and 3.23 eV by increasing the growth times.