Interest to ZnSxSe1-x alloys is due to their band-gap tunability varying S and Se content. Films of ZnSxSe1-x were grown evaporating ZnS and ZnSe powder mixtures onto SiO2, NaCl, Si and ITO substrates using an original low-cost method. X-ray diffraction patterns and Raman spectroscopy, show that the lattice structure of these films is cubic ZnSe-like, as S atoms replace Se and film compositions have their initial S/Se ratio. Optical absorption spectra show that band gap values increase from 2.25 to 3 eV as x increases, in agreement with the literature. Because S atomic radii are smaller than Se, EXAFS spectra confirm that bond distances and Se coordination numbers decrease as the Se content decreases. The strong deviation from linearity of ZnSe coordination numbers in the ZnSxSe1-x indicate that within this ordered crystal structure strong site occupation preferences occur in the distribution of Se and S ions. The behavior is quantitatively confirmed by the strong deviation from the random Bernoulli distribution of the three sight occupation preference coefficients of the strained tetrahedron model. Actually, the ternary ZnSxSe1-x system is a bi-binary (ZnS+ZnSe) alloy with evanescent formation of ternary configurations throughout the x-range.

The results of studying the growth of a ZnS–SiO 2 nanocomposite film by discrete thermal evaporation at lowered condensation temperatures using an ultrahigh-vacuum setup are presented. It is shown that ZnS–SiO 2 nanocomposite films contain an amorphous SiO 2 matrix and zinc-sulfide ZnS nanocrystals. The nanocrystallite shape and sizes depend on the condensation temperature.

ZnS x Se (1 − x ) ( x = 0.36, 0.68, and 0.73) films of various compositions are prepared by the thermal deposition of a mixture of zinc sulfide and zinc selenide powders in ultrahigh vacuum. It is shown that the produced films and the source materials are close in chemical composition. The crystal structure of the films is studied via X-ray diffraction. The local atomic environment of selenium and zinc atoms is studied by means of EXAFS spectroscopy.

The influence of the condensation temperature on the structure and optical properties of ZnS and ZnSe films is studied. The presence of the hexagonal phase, along with the cubic, is revealed in films deposited on the cleaved NaCl facet. The appearance of the hexagonal phase is explained by the mechanical stress produced at the film-substrate interface.

Here we report an investigation of structure and luminescence characteristics of ZnS nanostructures formed in porous anodic aluminum oxide (AAO). Nanostructures were obtained by physical vapor deposition of ZnS onto porous aluminum oxide templates possessing ordered system of channels. Scanning electron microscopy (SEM) studies reveal a periodic arrangement of nearly identical nanostructures (with diameters of similar to 50 nm and the height of 50 +/- 20 nm) in hexagonal close packed network with a spatial periodicity of similar to 100 nm. According to XRD ZnS nanostructures crystalize in AAO matrix preferably in sphalerite phase with preferred growth of cubic ZnS in (111) structure direction. Contrary ZnS@Al2O3 reference sample grown on smooth Al2O3 substrate contains metal Zn phase, originated from an enhanced adhesion of zinc atoms to the substrate at the initial stage of deposition. Raman spectra of both ZnS in AAO matrix and on smooth Al2O3 indicate the presence of ZnS-LO mode at similar to 345 cm(-1) corresponding to cubic ZnS phase. The luminuescence spectrum of zinc sulfide nanostructures in AAO matrix has main components located at 407, 445, 490, 517, 537 and 576 nm ascibed accordingly to luminescence of Al2O3 F+ and F centres, intrinsic luminescence of zinc sulphide and recombination of excitons at the ZnS surface states appearing due to interaction of semiconductor with the matrix material on ZnS/AAO interface. ZnS films grown on smooth Al2O3 does not provides luminescence due to the presence of the metal phase of Zn. (C) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

The atomic structure of zinc sulfide films obtained by thermal evaporation in ultrahigh vacuum at condensation temperatures of −100°C, −50°C, and 0°C was investigated. Structural states were assessed by means of X-ray diffraction and atomic force microscopy. Fourier transform was used to study the local atomic environment and acquire the structural information (interatomic distances and coordination numbers) by zinc K edge EXAFS spectroscopy.

Investigations of the luminescent characteristics of ZnSe and ZnS nanostructures obtained by thermal deposition on porous anodic aluminum oxide films are presented. Luminescence associated with the interaction of semiconductors with the matrix material was detected.

The influence of thermal annealing on the photoluminescence, electroluminescence, and the transmission and reflection spectra in nanocrystalline zinc sulfide films has been studied. All the samples exhibit a broad emission band, the intensity of which depends on the annealing temperature. It is shown that luminophors, the crystal lattice of which includes imperfections that appeared in the transition from wurtzite to sphalerite, feature the highest emission intensity.

An approach to fabricating electroluminescence devices is suggested in which an active ZnSe layer in a nanocomposite form (nanocrystallite embedded in an amorphous matrix) is used for the first time. In contrast to standard thin-film electroluminescence devices, no impurity doping of the active layer is required for providing radiation with a given wavelength. The current-voltage characteristic of a developmental device is taken, and the impedance of an electroluminescence capacitor is measured. The electroluminescence spectrum is found to have a maximum at a wavelength of 335 nm.

The effect of thermal annealing on the structure of nanocrystalline ZnS films obtained at negative (centigrade) condensation temperatures on NaCl, Si, and SiO2 substrates has been studied. It is shown that the structure of zinc sulfide films on Si and SiO2 substrates differs from that of films on NaCl substrates. The hexagonal phase appears in the films on NaCl and disappears upon annealing. The appearance and disappearance of this phase is due to the effect of stresses in the film-substrate system.

Here we report a novel approach for preparation of ZnSe nanodot arrays by physical vapor deposition on porous aluminum oxide templates possessing ordered system of channels. The structure of nanodot arrays was investigated by scanning electron microscopy and EXAFS-spectroscopy. The geometry of nanodots and local atomic structure parameters like the interatomic distances and coordination numbers of Zn and Se atoms are reported. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

A novel approach is presented for synthesis of ZnSe nanodot arrays by physical vapor deposition on porous aluminum oxide templates with ordered channels. The structure of nanodots was studied by scanning electron microscopy and EXAFS spectroscopy. Data were obtained for the sizes of nanodots in the array and local atomic structure parameters, i.e., the interatomic distances and coordination numbers, in comparison with the data for the ZnSe film synthesized on a smooth surface of nonporous Al2O3.

This paper presents the results of our study of the structural state and local atomic structure of zinc selenide films obtained by thermal evaporation in supervacuum at condensation temperatures of −150°C, 0, and 150°C. Structure-sensitive methods such as X-ray diffraction, atomic force microscopy, and EXAFS spectroscopy were used. The parameters of the local atomic environment (interatomic distances, coordination numbers) of zinc and selenium atoms were obtained by Fourier transformation.

The structure and electrophysical and optical properties of semiconductor ZnSe nanocomposite thin films are studied. These films are obtained by discrete thermal evaporation in an ultrahigh vacuum. ZnSe films are synthesized in various structural states in the condensation temperature range 2–200°C. The optical spectra of these films are studied in the visible region.