Some spectroscopic properties of gold nanorods according to a schematic quantum model founded on the dielectric behavior of the electron-gas confined in a box. I

The long-standing confined-electron-gas approach employed for simulating in a simple way the size-dependent "free electron" dielectric behavior of isotropic nanoparticles has been extended to the investigation of some spectroscopic properties of gold nanorods. The model adopted takes also into accounts size-independent interband effects estimated in a semiempirical way from bulk dielectric data. Predictions relative to the optical absorption and photoluminescence behavior, associated with the coherent, collective excitation of the electron gas, are derived on the basis of a fairly simple formalism, whose implementation allows to deal with a number of conduction electrons of the order of ca. 10(4), at a tolerable computational cost. The predictions of the model agree reasonably well with the few available experimental data. The nature of some approximations introduced suggests also the opportunity of a further analysis of specific points. (C) 2003 Elsevier Science B.V. All rights reserved.