Search

The results of the investigation of the electronic structure of the conduction band in the energy range 5-25 eV above the Fermi level E and the interfacial potential barrier upon deposition of aziridinylphenylpyrrolofullerene (APP-C) and fullerene (C) films on the surface of the real germanium oxide ((GeO)Ge) have been presented. The content of the oxide on the (GeO)Ge surface has been determined using X-ray photoelectron spectroscopy. The electronic properties have been measured using the very low energy electron diffraction (VLEED) technique in the total current spectroscopy (TCS) mode. The regularities of the change in the fine structure of total current spectra (FSTCS) with an increase in the thickness of the APP-C and C coatings to 7 nm have been investigated. A comparison of the structures of the FSTCS maxima for the C and APP-C films has made it possible to reveal the energy range (6-10 eV above the Fermi level E) in which the energy states are determined by both the π* and σ* states and the FSTCS spectra have different structures of the maxima for the APP-C and unsubstituted C films. The formation of the interfacial potential barrier upon deposition of APP-C and C on the (GeO)Ge surface is accompanied by an increase in the work function of the surface E- E by the value of 0.2-0.3 eV, which corresponds to the transfer of the electron density from the substrate to the organic films under investigation. The largest changes occur with an increase in the coating thickness to 3 nm, and with further deposition of APP-C and C, the work function of the surface changes only slightly. [ABSTRACT FROM AUTHOR]

Composite thin-film structures based on C/CdTe were prepared by discrete vacuum evaporation in a quasi-closed volume and by vacuum evaporation from a Knudsen cell. The synthesized fullerene samples contained cadmium telluride with a content ranging from 1 to 50 wt %. The morphology and composition of the films were controlled using scanning electron microscopy and energy-dispersive X-ray analysis. The optimum geometry, the total energy, and the spectrum of excited states of the fullerene-cadmium telluride molecular complex were calculated by quantum-chemical methods. The spectral dependences of the photo-luminescence, Raman scattering, extinction coefficient, and refractive index were measured for different compositions. It was found that, in contrast to the spectra of pure fullerene, the luminescence and absorption spectra of the fullerene doped with cadmium telluride exhibit an additional peak in the wavelength range of 600-620 nm. These data were interpreted as the existence of dipole-allowed transitions in the spectrum of excited singlet states of the fullerene due to the interaction with cadmium telluride. The composite films had an increased resistance to degradation under the action of oxygen and water vapor. [ABSTRACT FROM AUTHOR]

The evaporation of pure C60 films is investigated. The rates of evaporation of the fullerene are experimentally measured, and the saturated vapor pressures are determined in the temperature range 250–290°C. The influence of atmospheric oxygen and ultraviolet irradiation on the rate of evaporation of the fullerene is studied. It is shown that the evaporation parameters of pure C60 films differ substantially from the reference values. [ABSTRACT FROM AUTHOR]