5 research outputs found
Consequences of Confinement Conditions on Absorption in Molecular Nanofilms
This paper presents a model of molecular ultrathin crystalline film and analysis of dielectric properties of these spatially very restricted structures. Using the two-time dependent Green functions the energy spectrum and possible exciton states were determined and the dynamic permittivity was calculated. It was shown that the appearance of localized states in the boundary layers of the film depend on the thickness and the changing values of parameters in the border areas of the film. These localized states define schedule and determine the number of resonant absorption lines in the infrared area of the external electromagnetic radiation
Quantum size effects in the optical properties of organic superlattices containing 3, 4, 9, 10 perylene tetracarboxylic dianhydride (PTCDA)
71.35.Aa Frenkel excitons and self-trapped excitons, 33.20.-t Molecular spectra, 78.20.Bh Theory, models, and numerical simulation, 78.55.Kz Solid organic materials,
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 Nb1-x Snx Se2 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.Callaway model with Debye’s approximation of phonon states density is used to determine heat conductivity of some layered structures of Nb1-x Snx Se2 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