CeO2 Optical Properties and Electrical Characteristics

Abstract

The characterizations of optical dielectric function of the cerium dioxide (CeO2) were made by the spectroscopic ellipsometry (SE) technique using Kramers-Kronig relation and Tauc-Lorentz (TL) dispersion model. The results showed that the bandgap energy and refractive index of the CeO2 are about 3.32 eV and 2.18, respec-tively. According to the optical properties, the current conduction mechanisms in CeO2 thin films are Poole-Frenkel emission in high electric fields (> 2.36 MV/cm) at 450-500 K and Schottky emis-sion in medium electric fields (0.5-1.6 MV/cm) at 350-500 K. Consequently, the trap energy level and the Al/CeO2 barrier height are determined to be about 1.57{plus minus}0.01 eV and 0.63{plus minus}0.01 eV, re-spectively.