A5060991661- Liquid Crystal Research Advancements
- Photonic Crystals and Applications
- Luminescence Properties of Advanced Materials
- Gold and Silver Nanoparticles Synthesis and Applications
- Molecular spectroscopy and chirality
- Optical Polarization and Ellipsometry
- Photonic and Optical Devices
- Photoreceptor and optogenetics research
- Quantum Dots Synthesis And Properties
- Gas Sensing Nanomaterials and Sensors
- Chalcogenide Semiconductor Thin Films
- Surfactants and Colloidal Systems
- Photochemistry and Electron Transfer Studies
- Advanced Nanomaterials in Catalysis
- Copper-based nanomaterials and applications
- Quantum optics and atomic interactions
- Plasmonic and Surface Plasmon Research
- Nonlinear Optical Materials Studies
- Advanced Photocatalysis Techniques
- Glass properties and applications
- Silicon Nanostructures and Photoluminescence
- Analytical Chemistry and Sensors
- Solid State Laser Technologies
- Laser-Ablation Synthesis of Nanoparticles
- Optical Coatings and Gratings
University of Tartu
2014-2024
Sun Yat-sen University
2016-2019
Institute of Physics
2004-2012
National Academy of Sciences of Ukraine
2004-2008
Institute of Software Systems
2004
Energy migration (energy transfer among identical luminescence centers) is always thought to be related the concentration quenching in materials. However, novel Eu3+-doped Ba6Gd2Ti4O17 phosphor seems an exception. In series of Ba6Gd2(1- x)Ti4O17: xEu3+ ( x = 0.1, 0.3, 0.5, 0.7, and 0.9) phosphors prepared investigated, no found. Detailed investigations crystal structure properties reveal that nonoccurrence dimensional restriction energy inside lattices. Ba6Gd2Ti4O17, directly increasing...
Eu3+ ion can be effectively sensitized by Ce3+ through an energy-transfer chain of Ce3+-(Tb3+) n-Eu3+, which has contributed to the development white light-emitting diodes (WLEDs) as it favor more efficient red phosphors. However, simply serving for WLEDs one multicomponents, design n-Eu3+ energy transfer is undoubtedly underused. Theoretically, light achieved with extra blue and green emissions released from Tb3+. Herein, based on these three multicolor luminescence centers been realized in...
Energy transfer from Ce<sup>3+</sup> to Sm<sup>3+</sup> in orthosilicate host enhances the luminescence and shows promising application white LEDs.
The electro-optical response and the microstructure of multiwalled carbon nanotubes dispersed in nematic liquid crystals with negative dielectric anisotropy are investigated. In contrast to undoped crystals, crystal dispersions characterized by irreversible electro-optic or so-called memory effect. This effect is that light transmittance through sandwiched layer dispersion placed between two crossed polarizers considerably increases after electric field application cycle. state persisted...
The structural peculiarities and electro-optic performance of liquid crystal (LC)-colloidal nanoparticle (NP)-polymer (P) composites formed by photoinduced phase separation are considered. We classify these materials under two groups according to limiting cases polymer morphology. first group corresponding small concentration comprises LCs filled with NPs that stabilized a network. It is found that, in addition the light scattering caused LC orientational defects, refractive index mismatch...
A pronounced irreversible electro-optical response (memory effect) has been recently observed for nematic liquid crystal (LC) EBBA doped by multi-walled carbon nanotubes (MWCNTs) near the percolation threshold of MWCNTs (0.02-0.05 wt. %). It is caused homeotropic-to-planar reorientation LC in an electric field. This feature explained electro-hydrodynamically stimulated dispergation and formation a MWCNT network which acts as spatially distributed surface stabilizing planar state LC....
One of prospective ways for boosting efficiency luminescent materials is their combination with noble metal nanoparticles. Collective, so-called plasmon, oscillations surface electrons in a nanoparticle can resonantly interact incident or fluorescent light and cause an increase the absorption cross section radiative rate adjacent emitter. Plasmonic inorganic phosphors require gentle host crystallization at which added nanoparticles will not suffer from aggregation oxidation. The plasmonic...
We study the effects of droplet ordering in initial optical transmittance through polymer dispersed liquid crystal (PDLC) films prepared presence an electrical field. The experimental data are interpreted by using a theoretical approach to light scattering PDLC that explicitly relates and order parameters, characterizing both orientational structures inside bipolar droplets distribution droplets. theory relies on Rayleigh–Gans approximation uses Percus–Yevick take into account due positional...
Abstract Investigations of montmorillonite (MMT) clay mineral modification effects on electro‐optical properties nanocomposites, based the nematic liquid crystal 4‐pentyl‐4′‐cyanobiphenyl (5CB) and MMT have been carried out. Only composite with modified by an organic surface‐active substance, dioctadecyldimethylammonium chloride, has shown to manifest memory effect contrast. A polar dopant (acetone), added mixture, significantly increases homogeneity. Results IR spectroscopy measurements...
Sulfonated Zn phthalocyanine, as a prospective photosensitizer in the photodynamic therapy of tumors, is investigated by means Raman, infrared, and fluorescence spectroscopies. Conventional surface-enhanced spectra from this are obtained compared. Gold nano-islands attached to silica cores (Au-SiO2) proposed nanostructures providing plasmonically enhanced signals. Pronounced enhancement Raman infrared spectral bands sulfonated phthalocyanine allows their more convenient assignment with...
Noble metal nanoparticles are prospective of enhancement light trapping, absorption and overall efficency in solar cells. Light induced plasmonic electric field concentrated near such particles can support process the absorber layer cell. In spite clarity this general principle, discussions about most effective size, shape placement cell structure still under discussion. Here we report calculations inside CdTe doped by nanospheres effects caused phenomena. COMSOL 3D finite element...
An enhanced Raman scattering from a thin layer of adenine molecules deposited on graphene substrate was detected. The value enhancement depends the photon energy exciting light. benzene ring in structure molecule suggests π-stacking top graphene. So, it is proposed that signal explained by resonance electron transfer Fermi level to lowest unoccupied molecular orbital (LUMO) adenine.
Spectral, angular, and temporal distributions of fluorescence as well specular reflection were investigated for silica-based artificial opals. Periodic arrangement nanosized silica globules in the opal causes a specific dip defect-related spectra peak reflectance spectrum. The spectral position coincides with photonic stop band. latter is dependent on size angle observation. shape intensity can be controlled by variation detection angle. Fluorescence increases up to two times at edges dip....
The chemical spray pyrolysis method was used to deposit CuInS2 (CIS) thin films and Au nanoparticles (NPs) in two configurations: glass/Au-NP layer covered with film (Au-NP/CIS) glass/CuInS2 Au-NP (CIS/Au-NP). According X-ray diffraction (XRD), the of 2 mM HAuCl4 aqueous solution a volume 2.5 15 ml onto glass substrate at 340°C results metallic similar mean crystallite size range 30 - 38 nm. sizes remain 20 nm when grown CIS film. prepared show plasmonic light absorption increasing intensity...