Igor J. Šetrajčić

SURFACE LOCALIZATION OF ELECTRONS IN ULTRATHIN CRYSTALLINE STRUCTURES

Electron subsystem of ultrathin films was analyzed using Greens function method including quantum size effect and effect of boundaries on Hamiltonian parameters. We have calculated basic physical properties of electrons in crystalline films: energy spectra, possible states, space distribution of electrons and the position of Fermi level, which enabled the complete insight into the thermodynamic or conducting characteristics of observed film-structure. The comparison with crystal bulk have shown that electronic properties of the materials are strongly influenced by both the sample dimensions and boundary conditions. The numerical calculations performed for very thin crystalline metallic-like films show that localized states and spatial distribution of the (quasi)free electrons might be manipulated by varying the surface parameters which is significant for operation of devices based on thin films.

Consequences of Confinement Conditions on Absorption in Molecular Nanofilms

Consequences of Confinement Conditions on Absorption in Molecular Nanofilms I.J. Šetrajčića,∗, D. Rodić, J.P. Šetrajčić, A.J. Šetrajčić-Tomić, S.M. Vučenović University of Novi Sad, Faculty of Sciences, Department of Physics, 21000 Novi Sad, Vojvodina, Serbia University of Novi Sad, Faculty of Medicine, Department of Pharmacy, 21000 Novi Sad, Vojvodina, Serbia University of Banja Luka, Faculty of Sciences — Physics, 78000 Banja Luka, Republic of Srpska — B&H

Changes in optical characteristics of dielectric nanofilm structures in relation to bulk ones

A microscopic theory of optical properties of ideal ultrathin molecular films, was formulated in bosonic and nearest-neighbor approximation. Calculating of dynamical permittivity by the single-pole Greens functions have shown that the threshold of light absorption, refraction, reflection and transmission can be moved along frequencies, changing the film thickness. This can give a great contribution to practical ultrathin film engineering, especially to construction of drug delivery nanoparticles in nanomedicine.

HEAT CONDUCTIVITY OF SOME LAYERED STRUCTURES

Callaway model with Debye’s approximation of phonon states density is used to determine heat conductivity of some layered structures of Nb 1-x Sn x Se 2 type. In total relaxation time, a term proportional to squared frequency, typical for layered structures, is kept. Electronic heat conductivity is determined by Wiedemann–Franz law and BRT model for superconductors. In both cases, heat conductivity is determined numerically in the range of 2 – 200 K. Results correlate well with experimental data.