Aluminum-Doped Zinc Oxide Thin Films Prepared by Sol-Gel and RF Magnetron Sputtering |
| G.M. Wu, Y.F. Chen and H.C. Lu
Institute of Electro-Optical Engineering, Dept. of Chemical and Materials Engineering, Chang Gung University, Kweisan, Taoyuan 333, Taiwan R.O.C. |
| Full Text PDF |
| Zinc oxide (ZnO) thin films have become technologically important materials due to their wide range of electrical and optical properties. The characteristics can be further adjusted by adequate doping processes. In this paper, aluminum-doped zinc oxide thin films have been prepared on glass substrates using a sol-gel route and the radio-frequency magnetron sputtering process. The stoichiometry could be easily adjusted by controlling the nano-sized precursor concentration and the thickness by dip-coating cycles. On the other hand, the mixed N2O/Ar plasma gas provided adequate N doping for the RF sputtering process. The results showed the low electrical resistivity of 21.5 Ωcm with the carrier concentration of - 3.21 × 1018 cm-3 for the n-type aluminium-doped zinc oxide film. They were 34.2 Ωcm and + 9.68 × 1016 cm-3 for the p-type aluminium-doped zinc oxide film. The optical transmittance has been as high as 85-90% in the 400-900 nm wavelength range. The aluminium-doped zinc oxide (2 at.% Al) films exhibited the hexagonal wurzite structure with (002) preferred crystal orientation. The electrical characteristics were depicted by the gradual increase in N and NO that occupy the oxygen vacancies. |
| DOI: 10.12693/APhysPolA.120.149 PACS numbers: 81.15.Cd, 82.70.Gg, 77.55.hf |