High Transparent and Conductive TiO2/Ag/TiO2 Multilayer Electrode Films Deposited on Sapphire Substrate
Transparent conducting oxides attract intense interests due to its diverse industrial applications. In this study, we report sapphire substrate-based TiO2/Ag/TiO2 (TAT) multilayer structure of indium-free transparent conductive multilayer coatings. The TAT thin films were deposited at room temperature on sapphire substrates and a rigorous analysis has been presented on the electrical and optical properties of the films as a function of Ag thickness. The optical and electrical properties were mainly controlled by the Ag mid-layer thickness of the TAT tri-layer. The TAT films showed high luminous transmittance ~ 84% at 550 nm along with noteworthy low electrical resistance ~ 3.65 × 10−5 Ω-cm and sheet resistance of 3.77 Ω/square, which is better are than those of amorphous ITO films and any sapphire-based dielectric/metal/dielectric multilayer stack. The carrier concentration of the films was increased with respect to Ag thickness. We obtained highest Hackke’s figure of merit 43.97 × 10−3 Ω−1 from the TAT multilayer thin film with a 16 nm thick Ag mid-layer.
KeywordsTitanium dioxide Dielectric/metal/dielectric Silver Transparent conductive oxide Sputtering Thin films
The research was supported by the International Science and Business Belt Program through the Ministry of Science, ICT and Future Planning (2017K000488). This work was supported by the Technology Innovation Program, 10048568, Development of Manufacturing Technology of 1500 N Grade Sapphire for Optic and Display Component Applications funded by the Ministry of Trade, Industry and Energy.
- 3.Klein, A.: Transparent conducting oxides: electronic structure–property relationship from photoelectron spectroscopy with in situ sample preparation. J. Am. Ceram. Soc. 96, 331 (2013)Google Scholar
- 12.Ginley, D.S., Hosono, H., Paine, D.C.: Handbook of Transparent Conductors. Springer, New York (2010)Google Scholar
- 24.Ryou, J.H.: Gallium Nitride (GaN) on Sapphire Substrates for Visible LEDs Nitride Semiconductor Light-Emitting Diodes (LEDs) Materials, Technologies and Applications. ISBN: 978-0-85709-507-7, 66 (2014)Google Scholar
- 25.Prest, C.D., Memering, D.N., Rothkopf, F., Hill, M.D., Lynch, S.B., Tan, T.Y.: US Patent 0023430A1 (2014)Google Scholar
- 26.Mukherjee, S.: Applied Mineralogy: Applications in Industry and Environment, p. 37. Springer, Berlin (2012). ISBN 978-94-007-1162-4Google Scholar
- 27.MacLeod, A., Clark, C.: Optical Coating Design with the Essential Macleod. The Essential MacLeod Version 9. 6. 415, pp. 85716–95227. Thin Film Center Inc., 2745 E Via Rotonda, Tucson (2012)Google Scholar
- 36.Raether, H.: Surface plasmons on smooth and rough surfaces and on gratings. Springer, Berlin (1988)Google Scholar