Urbach Energy of Hexagonal ZnO and Mg 0.05 Zn 0.95 O Thin Film Grown by RF Sputtering
Sornchai T anunchai, Sripen T owta, Nik orn Mangk orntong, P ongsri Mangk orntong and Supab* Author for corresponding; e-mail address: supab@science.cmu.ac.th
Volume: Vol.32 No.3 (SEPTEMBER 2005)
Research Article
DOI:
Received: -, Revised: -, Accepted: -, Published: -
Citation: Anunchai S..T., Owta S..T., Orntong N.O..M. and Supab P.O..M.O., Urbach Energy of Hexagonal ZnO and Mg 0.05 Zn 0.95 O Thin Film Grown by RF Sputtering, Chiang Mai Journal of Science, 2005; 32(3): 453-458.
Abstract
The Urbach energy which is associated with Urbachs tail can be deduced from the absorption coefficient and depends on structural defects. Thus, the Urbach energy is used as a parameter to determine the optimum growth conditions of ZnO and Mg0.05Zn0.95O thin film grown by rf sputtering. The thin films were deposited from single target of ZnO and Mg0.05Zn0.95O onto glass substrates with no intentional heating under argon atmosphere of 30 militorr. The sputtering power was varied between 100-300 watts. It was found that at sputtering power of 150 watt the deduced Urbach energy has the lowest value indicating the optimum sputtering power.