화학공학소재연구정보센터
Current Applied Physics, Vol.10, No.1, 164-170, 2010
Epitaxial growth of highly transparent and conducting Sc-doped ZnO films on c-plane sapphire by sol-gel process without buffer
Highly transparent and conductive scandium doped zinc oxide (ZnO:Sc) films were deposited on c-plane sapphire Substrates by sol-gel technique using zinc acetate dihydrate [Zn(CH(3)COO)(2)center dot 2H(2)O] as precursor, 2-methoxyethanol as solvent and monoethanolamine as a stabilizer. The doping with scandium is achieved by adding 0.5 wt% of scandium nitrate hexahydrate [(ScNO(3)center dot 6H(2)O)] in the solution. The influence of annealing temperature (300-550 degrees C) on the structural, optical and electrical properties was investigated. X-ray Diffraction study revealed that highly c-axis oriented films with full-width half maximum of 0.16 degrees are obtained at an annealing temperature of 400 degrees C. The surface morphology of the films was judged by SEM and AFM images which indicated formation of grains. The average transmittance was found to be above 92% in the visible region. ZnO:Sc film, annealed at 400 degrees C exhibited minimum resistivity of 1.91 x 10(-4) Omega cm. Room-temperature photoluminescence measurements of the ZnO:Sc films annealed at 400 degrees C showed ultraviolet peak at similar to 3.31 eV with a FWHM of 11.2 meV, which are comparable to those found in high-quality ZnO films. Reflection high-energy electron diffraction pattern confirmed the epitaxial nature of the films even without introducing any buffer layer. (C) 2009 Elsevier B.V. All rights reserved.