The effect of oxygen ratio on the crystallography and optical emission properties of reactive RF sputtered ZnO films

• Published in: Physica. B, Condensed matter Vol. 405; no. 4; pp. 1081 - 1085
• Main Authors: Al-Hardan, N.H., Abdullah, M.J., Abdul Aziz, A., Ahmad, H., Rashid, M.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15-02-2010; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Ii-vi semiconductors; Luminescence; Optical properties; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Physics; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; X-ray diffraction; Zinc oxide; X-ray diffraction; Zinc oxide; Optical properties; Luminescence; Refractive index; Photoluminescence; XRD; Spectral line shift; Thin films; Ultraviolet radiation; Reactive sputtering; Absorption spectra; Microstructure; Radiofrequency sputtering
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2009.11.006

ZnO thin films were successfully grown on fused silica substrates by reactive RF sputtering. The ratio of the reactive oxygen (O
2) gas to the sputter argon (Ar) gas varied from 10% to 90%. The XRD results showed a single diffraction peak of (0
0
2) phase, with the values of FWHM tend to decrease as the oxygen ratio increases. The prepared films showed a good optical transmittance with the decrease of refractive index from 2.2 to 1.9 as the oxygen ratio increases. The PL spectra showed a single UV emission with a broad peak at the visible and infrared regions. The UV peak shifted from 3.25 to 3.17
eV, while the intensity decreases as the oxygen ratio increases. The work discussed the influence of the O
2 ratio on the structural and optical properties of the films.