Results 1 - 10 of 12
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[en] The results of comparison studies of the CdTe-CdS interphase boundary in Au/CdTe/CdS sandwich structures synthesized on a substrate of artificial fluorophlogopite mica in highly nonequilibrium conditions (with a substrate temperature Ts = 125 K) and in quasi-equilibrium conditions (Ts > 720 K) are reported. The X-ray diffraction patterns and a capacitance-voltage characteristic are also reported. It is shown that highly nonequilibrium conditions allow synthesis of structures with excellent crystalline quality and with an interphase boundary that is no worse than in the structures grown under equilibrium conditions
[en] The results of electron microscopy and sensor studies of nucleation of oriented CdTe films synthesized under highly nonequilibrium conditions on the substrate cooled to Ts = 228 K are reported. The photomicrographs of the surface, the distribution functions of the islands of a new phase at the initial stage, and the kinetic curves of the sensor analysis obtained during the synthesis are presented. It is shown that the experimental results can be noncontradictorily accounted for by the spinodal evolution character of the population of adatoms
[en] The results of comparative studies of electrical and galvanomagnetic properties of cadmium telluride films are reported. The films were synthesized under highly nonequilibrium conditions by the methods of a thermal screen and a quasi-closed volume. The temperature dependences of the conductivity, Hall coefficient, and effective Hall mobility are reported. As a result of experimental data, it is concluded that the method of a thermal screen favorably affects the stoichiometry of the composition and, thus, is conducive to obtaining films with a lower concentration of defects.
[en] The results of experimental studies of electrical and galvanomagnetic properties of CdTe films synthesized under highly nonequilibrium conditions via vapor condensation on a substrate cooled with liquid nitrogen are reported. The temperature dependences of dark conductivity, current-voltage characteristics with and without illumination, temperature dependences of the Hall coefficient RH and effective Hall mobility μH in the planar geometry, and dark current-voltage characteristics in the sandwich geometry are reported. Anisotropy of conductivity is revealed. It is shown that the electrical and galvanomagnetic properties of the films are consistently described by a percolation model of charge transport, according to which, at high temperatures, the charge transport takes place over the percolation level of the valence band, and at low temperatures, over the percolation level of the impurity band.
[en] The results of technological experiments and structural investigations of films of CdSexTe1-x alloys synthesized by the thermal-screen method on heated and cooled substrates (under highly nonequilibrium conditions) are presented. It is shown that the synthesis of the entire range of compositions of alloy films with the structure from epitaxial to amorphous is possible from the mechanical mixture of CdSe and CdTe powders of the same composition under highly nonequilibrium conditions. The electron diffraction patterns and the microphotographs of film surfaces are reported.
[en] Structural (X-ray and electron diffraction) investigations of the interface in films of (Zn 1-x CdxTe) 1-y (In2Te3) y alloys and zinc selenide grown on glass substrates under strongly nonequilibrium (substrate temperature Ts = 200 K) and quasi-equilibrium (Ts = 473 K) conditions have been performed. It is shown that growth of alloy films occurs through formation of nuclei of different shape and orientation. It is established that the alloy films grown on a cooled substrate have better (with respect to crystalline orientation) structural quality in comparison with similar films grown on a heated substrate, where Ostwald ripening plays an important role during growth
[en] The results of crystallinity studies of an ensemble of cadmium-sulfide nanowire crystals synthesized from the vapor phase in a quasi-closed volume are reported. The nanowires are from 10 nm to several micrometers in diameter and tens of millimeters in length. Electron diffraction and luminescence are studied. The diffraction patterns and micrographs are presented. The results suggest a high degree of crystallinity of the nanowires.
[en] Structural and technological studies of processes in which cadmium-sulfide nanowhiskers are synthesized in a quasi-closed volume by the method of vacuum evaporation and condensation are reported. It is demonstrated that the processes are in agreement with the classical vapor–liquid–crystal model. Micrographs of the objects in different formation stages are presented.
[en] The effect temperature has on the composition of a vapor phase passed through a thermal field after the evaporation of a mechanical mixture of the powders of cadmium selenide and telluride is studied. It is found that the composition of the vapor phase can be changed throughout the range of concentrations by varying the temperature. The results of the study are satisfactorily explained by the effect temperature has on the particle distribution function in correspondence to the weights of the molecules constituting the mixture. The temperature dependences of the composition of the vapor phase are presented for several mechanical mixtures of the powders of (CdSe)x(CdTe)1−x, where x = 0.45–0.90.
[en] An epitaxial cubic 350-nm-thick cadmium selenide has been grown on silicon for the first time by the method of evaporation and condensation in a quasi-closed volume. It is revealed that, in this method, the optimum substrate temperature is 590°C, the evaporator temperature is 660°C, and the growth time is 2 s. To avoid silicon etching by selenium with formation of amorphous SiSe2, a high-quality ~100-nm-thick buffer silicon carbide layer has been synthesized on the silicon surface by substituting atoms. The powder diffraction pattern and the Raman spectrum unambiguously correspond to cubic cadmium selenide crystal. The ellipsometric, Raman, and electron diffraction analyses demonstrate high structural perfection of the cadmium selenide layer and the absence of a polycrystalline phase.