Influence of oxygen partial pressure on the structure and photoluminescence of direct current reactive magnetron sputtering ZnO thin films

• Published in: Thin solid films Vol. 473; no. 1; pp. 58 - 62
• Main Authors: Hong, Ruijin, Qi, Hongji, Huang, Jianbing, He, Hongbo, Fan, Zhengxiu, Shao, Jianda
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.02.2005; Elsevier Science
• Subjects: 68.55.J; 78.55; 81.15; 84.40.F; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Luminescence; Optical properties; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Physics; Sputtering; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Zinc oxide; 81.15; Optical properties; Luminescence; 68.55.J; Zinc oxide; 78.55; Sputtering; 84.40.F; Oxygen; Inorganic compounds; Pressure effects; Transition element compounds; Photoluminescence; Orientation; Nonstoichiometry; Thin films; Cathode sputtering; Zinc oxides; Tensile stress; 78.55 Zinc oxide; Partial pressure; Mechanical stress; Direct current; Ambient temperature; Reactive sputtering; Optical films
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2004.06.159

The effects of oxygen partial pressure on the structure and photoluminescence (PL) of ZnO films were studied. The films were prepared by direct current (DC) reactive magnetron sputtering with various oxygen concentrations at room temperature. With increasing oxygen ratio, the structure of films changes from zinc and zinc oxide phases, single-phase ZnO, to the (002) orientation, and the mechanical stresses exhibit from tensile stress to compressive stress. Films deposited at higher oxygen pressure show weaker emission intensities, which may result from the decrease of the oxygen vacancies and zinc interstitials in the film. This indicates that the emission in ZnO film originates from the oxygen vacancy and zinc interstitial-related defects. From optical transmittance spectra of ZnO films, the plasma edge shifts towards the shorter wavelength with the improvement of film stoichiometry.