First-principles study of the optical properties of pure alpha-Al2O3 and La aluminates

摘要

The optical properties of high k-gate alpha-Al2O3 and the effect of doping La have been studied by first principles using the density functional theory. The calculations were performed using the full potential linearized augmented plane wave (FP-LAPW) method with the generalized gradient approximation (GGA). The calculated optical properties and EEL spectrum yield a static refractive index of 1.64 and a plasmon energy of 21.6 eV for pure alpha-Al2O3. Substitution of La for Al increases the static refractive index to 1.73, but decreases the plasmon energy to 17.8 eV for the Al1.5La0.5O3 molecule.