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A narrow-band green emitting K 3 Tb(PO 4 ) 2 phosphor has been synthesized by a novel single-crystal growth approach involving the application of an inert flux. Its structural and spectroscopic peculiarities have been systematically studied by means of single-crystal X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy analysis, and diffuse reflectance, infrared and photoluminescence spectroscopy. The layered framework of the title compound is organized by linking together slightly distorted phosphate tetrahedra with non-condensed TbO 7 polyhedra into [Tb(PO 4 ) 2 ] 3- sheets interconnected by potassium cations. K 3 Tb(PO 4 ) 2 reveals an intense slow green photoluminescence (PL) (decay time constant τ is near 2.6 ms) under excitation in the range from VUV (100 nm) up to blue light (484 nm). Intensive narrow lines of the 5 D 4 → 7 F 6-0 (4f 8 → 4f 8 ) radiative transitions in Tb 3+ ions form the PL spectra. Besides, fast violet PL (time constant τ < 20 ns) occurs under PL excitations in a narrow range from 250 to 325 nm. Dependencies of the PL quantum yield, and the green and violet PL decays on the excitation wavelength have been analyzed taking into account the multi-phonons, cross-relaxation processes and exciting light absorption by the inherent defects in the K 3 Tb(PO 4 ) 2 crystal lattice. The dependency of the complex characteristics of PL quantum yield on the excitation wavelength and violet photoluminescence is ascribed to the formation of Tb 4+ ions. The color coordinates and color purity of the emission were estimated for the cases of PL excitation in the 160-371 nm spectral range. It has been shown that these characteristics are similar to or even better than those reported for conventional commercial green phosphors. The high values of correlated color temperature ( T  > 4863 K) of the emission indicates the potential use of K 3 Tb(PO 4 ) 2 for enhancing cold-light emitting devices.

Micro/nanosized carbon materials were prepared by electrochemical exfoliation method in the forms of the colloids and thin films. Scanning electronic microscopy, optical and luminescent microscopy, and Raman scattering and luminescent spectroscopy were applied for characterization of materials. The wide photoluminescence band in the visible spectral region was observed for each of the samples. The shape of the photoluminescence band depends on excitation wavelength and on the size of the particles. At least two components with maxima at ~580 and ~710 nm can be distinguished in the photoluminescence spectra. The relations between the photoluminescence properties and morphology of the samples have been described and discussed.

Confocal micro-Raman spectroscopy is used as a sensitive tool to study the nature of laser-induced defects in single-layer graphene. Appearance and drastic intensity increase of D- and D' modes in the Raman spectra at high power of laser irradiation is related to generation of structural defects. Time- and power-dependent evolution of Raman spectra is studied. The dependence of relative intensity of defective D- and D' bands is analyzed to relate the certain types of structural defects. The surface density of structural defects is estimated from the intensity ratio of D- and G bands using the D-band activation model. Unusual broadening of the D band and splitting of the G band into G - and G + components with redistribution of their intensities is observed at high laser power and exposition. Position of the G + band is discussed in relation with nonuniform doping of graphene with charge impurities. Simultaneous presence in the Raman spectra of heavily irradiated graphene of rather narrow G band and broaden D band is explained by coexistence within the Raman probe of more and less damaged graphene areas. This assumption is additionally confirmed by confocal Raman mapping of the heavily irradiated area.

The set of composite materials that consist of micro/nanocellulose and complex K 2 Eu(MoO 4 )(PO 4 ) luminescent oxide particles was prepared. The composites were studied by means of scanning electron microscopy, XRD analysis, dilatometry, differential scanning calorimetry and thermogravimetric analysis, and dielectric and luminescence spectroscopy.Dependencies of density, crystallinity, relative extension, thermal extension coefficient, dielectric relaxation parameters, intensity and shape of photoluminescence bands on temperature, and content of oxide component were studied. The structure of the composite without oxide is formed by grains of nearly 5-50 μm in size (crystallinity is about ~56%). Structure of the micro/nanocellulose samples which contain oxide particles is similar, but the cellulose grains are deformed by oxide particles. Dependencies of the abovementioned properties on temperature and oxide content were analyzed together with data on the size distribution of oxide particles for the samples for various oxide and molecules of water concentrations.