The effect of silver nanoparticles (NPs) on spectral-luminescent and generation properties of ethanol solutions of vinylogous series neutral merocyanine dye has been studied. Adding silver NPs to dye solutions has led to a growth of optical density D and fluorescence intensity IFL of the dye molecules. With lengthening of a polymethine chain the silver NPs' effect on the D and IIFL values has been increasing. Whilst, a spectral overlap between the silver NPs and merocyanines has been decreasing. It is argued that the effect of the silver NPs on optical properties of the dye solutions may be related to the growth in the value of electron dipole moment of ground-to-the first excited state transition at the lengthened polymethine chain. The dye fluorescence quantum yields and lifetimes in the presence of silver NPs have been measured. Adding the silver NPs to the merocyanine ethanol solutions has led to the reduced dye stimulated emission generation threshold (PTR). A decrease in the value PTR corresponds to the changes observed for the D, IFL values and dye luminescence quantum yields.

The effect of laser radiation on the structural and optical properties of graphene oxide dispersed in water was studied. It was shown that under laser ablation a significant reduction in the size of graphene oxide sheets can be achieved. In this case, the resulting main parts of particles have a size of about 110–120 nm, and are similar to graphene quantum dots. The Raman spectra indicate the reduction of graphene oxide during laser radiation. The thickness of the formed particles practically was not changed, since the ID/IG ratio has close values. The prepared dispersions of graphene oxide exhibit wide luminescence bands in the region of 400–600 nm with a maximum of about 450 nm and a lifetime of 1.6 ns. It was shown that by laser ablation it is possible to achieve a significant increasing in the luminescent ability of graphene oxide in an aqueous solution. In this case, the luminescence intensity increased by almost 2 times, while the optical density of the solution was increased by only 5 % relative to the initial dispersion. The results can be used to create organic luminescent materials, in optical nanotechnology, as well as in photovoltaics, biophysics and bioimaging.

Исследовано влияние наночастиц (НЧ) серебра на спектрально-люминесцентные и генерационные свойства положительно сольватохромного мероцианинового красителя в этанольном растворе. Обнаружен рост сечения поглощения, интенсивности и длительности флуоресценции красителя при добавлении в раствор НЧ. Это обусловливает снижение порога генерации мероцианина. В результате в присутствии НЧ серебра (CAg=10-12 mol/L) ее удалось получить при той же концентрации (10-4 mol/L) красителя, при которой она не была достигнута в их отсутствие. Показательно, что плотность мощности лазерной накачки в первом случае была меньше, чем в последнем. Ключевые слова: мероцианиновый краситель, наночастицы серебра, плазмонный эффект, интенсивность поглощения и флуоресценции, вынужденное излучение.

Spectral-luminescent properties of polymethine dye in ethanol solution were studied upon the addition of gold and silver nanoparticles. The absorption spectrum of Au nanoparticles has a large degree of overlap with the absorption and fluorescence spectra of the dye than the absorption spectrum of Ag. In the presence of plasmon nanoparticles, both the absorption and fluorescence of the polymethine dye was increased. The position of the maxima of the absorption and the fluorescence bands of the dye and their half-width were not changed. The growth of fluorescence in 4 times was recorded for the concentration of Ag nanoparticles, equal to 3*10-14 mol/l, and for the concentration of Au nanoparticles, equal to 7*10-11 mol/l. The greatest increase in the fluorescence intensity of polymethine was registered for solutions with gold nanoparticles. The enhancement of the fluorescence of the dye and the decrease in its lifetime can be connected with an increase in the rate of electronic transitions in dye molecules that are located in the near field of metallic nanoparticles with excited plasmons. The decrease in the intensity of the luminescence of the dye at high concentrations of nanoparticles can be the result of nonradiative energy transfer from polymethine molecules to metal particles, which leads to a decrease in the probability of radiative decay of excited molecules.

The results of the investigation of the microstructural and the optical properties of tin oxide films obtained by electrochemical oxidation are presented in the article. Synthesis was conducted anodized dioxide tin in aqueous solution of sodium hydroxide and oxalic acid. Synthesis of porous tin dioxide was carried out by single-step or multistage methods. The time characteristics of the anodizing process in various electrolytes have been studied. There is a different nature of the time dependence of magnitude of the current anodizing from the chemical composition of the electrolyte. Obtained electron microscopic pictures membranes porous dioxide. The pore sizes of the tin dioxide films were determined. Microanalysis of the quantitative elemental composition of the films showed the formation of SnO2 oxide in the process of electrochemical anodization. The luminescence and Raman scattering spectra of SnO2 films obtained in various electrolytes during the one-stage and two-step methods of synthesis have also been studied. The change in the chemical composition of the electrolyte used or the method of synthesis of tin dioxide films does not lead to the appearance of additional luminescence bands in the luminescence spectra. There is only redistribution in the intensities of the existing luminescence bands. Spectra of Raman scattering of films obtained in NaOH correspond to the literature data. In the case of anodizing in an electrolyte based on H2C2O4, the Raman scattering spectra differ from the spectra observed for the SnO2 film anodized in NaOH and for tin dioxide nanostructures obtained in other studies. At the same time spectra of Raman scattering films the same with the one-stage and two-stage methods of synthesis.

The article deals with a new trend in the teaching of theoretical physics - method of mathematical, functional, dynamical theoretical physics. In which the important role belongs to the inner driving forces: logic, ideas, principles, serving as a backbone factor. Thus, physical and mathematical, philosophical and education approach, being at the categorical level an integral part of functioning and development of theoretical physics, represents the variety of coexisting and consequently changing specific structures of the physical object of differentscale, providing finally establishment of the current unified physical theory. This is why the solution of the methodological and dialectical problems of theoretical physics is of high value.

The results of studies of photovoltaic properties of solar cells based on porous tin oxide films, sensitized with an organic dye are presented. Porous films were prepared by electrochemical anodization of tin in alkaline electrolytes based on aqueous solution of NaOH and aqueous ammonia NH4OH. It was found that the time of anodizing of the Sn films affects on conversion efficiency of light energy into electrical energy. Increasing of the sorption time leads to an increase of the number of molecules on the surface of the porous film. For the solar cell based on tin oxide there is a strong dark current, which significantly reduces the efficiency of conversion of light energy into electrical energy.