LAUSR

The electronic structures and associated optical properties of aluminum, copper, and silver were investigated in bulk, thin-film and nanoparticle forms using first-principles band structure methods. The calculations show the progression from continuous bands to subbands to discrete states as spatial confinement is imposed in one and three dimensions. The associated optical properties described by the imaginary component of the dielectric function, e2(ω), were also investigated. The interband contributions to e2(ω) were calculated from the band structure, while the intraband contributions were calculated using the Drude theory for free electrons. Both contributions to e2(ω) are needed to understand the optical properties of metals and to interpret their reflectance spectra. The interband transitions need to be considered to explain reflectivity at energies lower than the plasma frequencies, but not all interband transitions result in reflectance peaks since they are significantly weaker compared to the int...