Characteristics of nanocrystalline CeO2 thin films deposited on different substrates at room temperature

Abstract

Nanocrystalline cerium oxide (CeO₂) thin films have been deposited over Si (100), Ni-W (200) and Al₂O₃ (0006) substrates at room temperature by RF magnetron sputtering. The effect of RF sputtering power and deposition pressure on the optical and wettable properties of CeO₂ thin films has been investigated. X-ray diffraction patterns show the dominant single orientation (111) of CeO₂ thin films deposited on different substrates at 150 W applied RF power and 5mTorr deposition pressure.But the value of full width at half maxima is found to be different on different substrates and varies in the range from 0.47°-0.65°. The corresponding crystallite size is also found to be varying from 16.94-12.46 nm. For these deposition parameters ellipsometer results reveal that the refractive index and band gap values are close to that of standard values. Thus, our results demonstrate that following sputtering process it is possible to deposit highly crystalline single oriented (111) CeO₂ thin films over different substrates even at room temperature simply by optimizing process parameters. Further, contact angle measurements indicate that all the deposited CeO₂ films show hydrophobic in nature.