Optical properties of quantum confined small metallic particles with diffuse surface

In this modified quantum sphere model, the dielectric function for small metallic particles is calculated on taking account of a diffuse surface instead of a hard sphere which inherits with an infinite potential well. In addition to the electrostatic and exchange correlation potentials as usually applied to the self-consistent spherical jellium background model (SJBM) in free metallic particles, we also adopt an effective curved potential well which is relevant to the medium embedding of the metallic particles. Using an appropriate effective pontential, the dipole matrix elements and eigen energy levels are calculated numerically by electron eigenfunctions confined within the particles. As a result, the surface plasmon frequency is simulated numerically as a function of particle size R. The blue and then red shift of the optical absorption peak as the particle size reduces from several hundred angstroms to several nm can be successfully addressed by this unique model. (C) 1997 Elsevier Science Ltd.