Opto-electronic properties of titanium-doped indium-tin-oxide films deposited by RF magnetron sputtering at room temperature

Opto-electronic characteristics of indium-fin-oxide (ITO)-doped titanium films deposited on a Coming 7059 glass substrate was prepared by radio frequency (RF) magnetron sputtering at various sputtering powers with a titanium target and various post-annealing temperatures. The results indicate that the carrier concentration of the ITO films increases with the function of titanium doping, but the mobility decreases. When the titanium target power is set at 5 W, the mobility exhibits a maximal value, but the carrier concentration is minimal thus the resistivity shows a minimal value. The transmittance of all titanium-doped ITO films reaches 70-85% in the 300-800 nm wavelength range. After annealing, the preferred crystallization plane of the ITO and ITO:Ti films was the (2 2 2) plane. The carrier concentration decrease is dependent on increasing annealing temperature. The optical transmittance of 90% at the wavelength of 550 nm can be observed. The study results also show that the optical energy band gap increases with increasing annealing temperature and the maximum value is 3.97 eV at the growth condition of 723 K and Ti 5 W was. (c) 2006 Elsevier B.V. All rights reserved.