The work is aimed to consider photocatalytic efficiency and photoluminescence dependence on oxygen vacancies and other crystal lattice defects in ZnO nanosheets in order to provide their regulation and perdictionA synthesis via precipitation method under different conditions followed by hydrothermal treatment under different temperatures to obtain series of nanosheet samples with various amounts of defects was performed. Obtained samples were fully characterized (SEM, XRD, FTIR, XPS, Raman, absorbance spectra). A novel approach has been proposed and applied to determine the amount of oxygen vacancies and defects from XPS and Raman spectroscopy data. Quantum-chemical calculations (DFT) were performed to obtain density of states and band structure and to study the impact of lattice parameters and oxygen vacancies on electronic structure.The photocatalytic properties under UV and visible light irradiation were studied. Relations between morphological, structural parameters and functional properties (photoluminescent and photocatalytic) of ZnO nanosheets using quantitative structure-property relationship (QSPR) method were established. The impact of defects in combinations with other parameters on functional properties was demonstrated. Revealed de-pendencies and QSPR model provide a possibility to predict functional properties of nanosheets can be used for the development of new materials.

Optical interference studies of graphitized layers formed in diamond by ion implantation and annealing provided the data on the depth and the thickness of the layers as well as their optical parzmeters. The latter were found to be close to those of dispersed graphite. Cathodoluminescince analysis of implanted diamond samples gave evidence of vacancy migration over macroscopic distances (~001μ).

Due to the metastability of diamond, it tends to transform to graphite if the lattice damage density exceeds a critical value. Optical and electrical measurements on the diamond structures comprising ion-implantation-induced buried graphitized layers were performed. The parameters of the layers were found to be close to those of dispersed graphite. Raman spectra indicated the presence of considerable tension in the part of the crystal close to the boundaries of the layers. Cathodoluminescence analysis of implanted diamond samples gave evidence of vacancy migration over macroscopic distances (∼100μm).

Optical interference studies of graphitized layers formed in diamond by ion bombardment and annealing provided the data on the depth and the thickness of the layers as well as their optical parameters. The latter were found to be close to those of dispersed graphite. Cathodoluminescence analysis of diamond samples implanted with fluences below and above the threshold of formation of the graphitized layer has shown that the conditions of formation and/or properties of the optical centres in the area with the buried graphite layer are different from those in the area without the layer which might to be due to the considerable tension in the part of the crystal between the surface and the buried graphitized layer.

Dense diamond-like carbon (DLC) thin films were deposited at room and liquid nitrogen temperatures on Si and SiO2 substrates by pulsed-laser sputtering of a graphite target in a high-vacuum (similar to 10(-6) Torr) chamber. The high density (similar to 3.05 g/cm(3)) of the films was evaluated by comparison of the intensity of carbon core electron excitation energy peaks in X-ray photoelectron spectra (XPS), measured for diamond, graphite and DLC films. Direct experimental evidence is presented for the first time that DLC films deposited at room temperature are essentially amorphous. Graphite nanocluster formation is observed as the appearance of a graphitic nanocluster system suspended in a dense sp(3) amorphous matrix. Data obtained by Raman spectroscopy, IR vibrational spectroscopy, XPS, electron energy-loss spectroscopy (EELS) and transmission electron microscopy (TEM) show that the transformation of the amorphous mixture of sp(3) and sp(2) bonded carbon atoms into the graphitic nanocluster system occurs as a result of the ordering of the sp(2) bonded carbon atoms in the process of annealing at temperatures which are only about two times higher than the temperature of deposition. (C) 1997 Elsevier Science S.A.

A method of diamond-like coating deposition on silicon and quartz, that can be compatible with growth processes of semiconductor and superconductor films, is described. These carbon thin films were prepared by pulsed laser sputtering of a graphite target in a high-vacuum (∼ 10−6 Torr) environment. Investigations by a variety of spectroscopic techniques demonstrate that the films have a high density (∼ 2.9 g/cm3) close to the density of diamond, a high ratio of sp3 to sp2 bonding (0.750.25), and IR transparency. The films were hard, adhesive to the substrate and had a high resistivity. It was found that hydrogen is incorporated into the films up to ∼ 10 at% due to reactions of sputtered carbon particles with residual hydrocarbons in the high-vacuum environment.