Comparative Study Of Measurement Methods Of Solids’ Dielectric Function

The optical properties of solids are fundamental parameters, they are necessaryfor studying materials’ radiation characteristics. Intrinsic properties of solids aredetermined by three basic physical processes: electronic transitions, lattice vibrationsand free-carrier effects. The dominant physical process depends on the materials andspectral region of interest.In addition, temperature is also an important factorinfluncing the solids’ properties because of its effects on physical process.I caculatesthe wavelength dependence of dielectric constant of some metals such as Ag, Au, Cu,Ni at wavelength of0.1~10μm using Lorentz-Drude and Drude model, and that ofsemiconductors like SiC, GaN in the far infrared using Huang-Born model. Iintroduce several different methods of measuring solids’ optical properties,includingreflectometry with and without K-K analysis, transmission, absorption andellipsometry, evaluate every methods’ advantage and disadvantage, and study thesensitivity of reflectometry and ellipsometry.I also analyze the temperaturedepedence of Y2O3’ optical properties based on pole-fit model and that of severalmetals with the use of Holstein phonon-electron scattering model, Lawrenceelectron-electron scattering model and a simplified model. The study shows that thereal parts of Y2O3’ dielectric constant and refractive index in the far infrared areaincrease as temperature grows, while the image parts don’t increase obviously.According to Drude model, ωcgrows rapidly. The real parts of metals’ dielectricconstant increase with temperature, while the influence of temperature on otheroptical properties of metals is complex. Experiments are also done to study thetemperature dependence of Cu’s optical properties.It shows that as temperatureincreases, n of Cu grows, while k, absolute value of1,2grow first then drop.Atlow temperature, experimental value with short wavelength fits the calculation value.