Volume 3 Issue 3
Authors: Divya Jyoti; Devendra Mohan
Abstract: The growth of nanostructured TiO2 on indium tin oxide (ITO) coated glass substrate has been reported. A thin film of TiO2 nanoparticles has been first layered down by dip coating and annealed followed by growth of anatase TiO2 nanotubes with a remnant blocking layer by solvothermal process. The novelty of the task lies in the formation of blocking layer beneath the nanotubes to be employed as photoanode in front side illuminated dye-sensitized solar cell. The morphology and microstructure of the nanotubes have been characterized by x-ray diffraction and electron microscopy, Raman spectroscopy, UV-visible spectra. Dye-sensitized solar cell has been assembled using this nanotube film as photoelectrode. The performance of the cell has been analyzed on the basis of incident photon to current conversion efficiency (IPCE) spectra and current-density, voltage (JV) characteristics. The observed efficiency value is 7.28%.
Keywords: Blocking Layer; Pinning; Fermi Level; Extinction Length
Authors: Alla Dovlatova; Dmitri Yerchuck; Felix Borovik
Abstract: The concept of the quantum Fermi liquid for the description of (quasi)-1D electronic systems is recovered. The model of the (quasi)-1D quantum Fermi liquid is developed on the example of the trans-polyacetylene and it is the generalization of the well-known model of organic (quasi)-1D conductors, elaborated by Su, Schrieffer and Heeger (SSH-model). It is shown, that the spin-charge separation effect can be realized in (quasi)-1D quantum Fermi liquids. It has a topological soliton origin in distinction from a spinon-holon spin-charge separation effect, predicted by the Tomonaga-Luttinger liquid model. The model presented allows to extend the limits of the applicability of the SSH-model to the electron-electron correlated (quasi)-1D-systems without any restriction on an electron-electron interaction force. The (quasi)-1D-systems with a strong electron-phonon interaction and/or a strong electron-photon interaction can be also described within the framework of the 1D quantum Fermi liquid model proposed. The practical significance of the model proposed consists in the clarification of the nature of charge and spin carriers and in the clarification of the origin of mechanisms of the quasiparticles’ interaction in the (quasi)-1D-systems. The model predicts the formation of longlived coherent, squeezed and entangled states of phonons in (quasi)-1D electronic systems with strong electron-phonon interaction at room temperature and even higher. It seems to be significant for the elaboration of the devices of the nanoelectronics, of the spintronics and of the other modern nanotechnology branches, based on the use of (quasi)-1D-systems, in particular, the nanotubes.
Keywords: Electron-Phonon Interaction; Electron-Photon Interaction; Spin-Charge Separation; Fermi Liquid
Authors: Yevgen Korniyenko; Yevgen Posokhov
Abstract: It has been shown that derivatives of 2,5-diaryl-1,3-oxazole can be used as fluorescent probes to monitor the changes in physico-chemical properties of human erythrocyte membranes under the action of low molecular weight cryoprotectants such as glycerol and 1,2-propanediol. It has been found that increase in cryoprotectant concentration increases hydration of erythrocyte membrane. The minimal concentration of the cryoprotectant, which causes the perturbation of the erythrocyte membrane, has been estimated to be 0.5 % and 5.0 % for glycerol and 1,2-propanediol, correspondingly. Using a set of fluorophores with different locations in lipid bilayer enabled us to show that the increase in the membrane hydration occurs in polar regions of the membrane (in the areas of glycerol residues of phospholipids, carbonyl groups of phospholipids and in the area of methylene groups in the vicinity of carbonyl groups of phospholipids), while no changes in hydration have been observed in the most hydrophobic regions of the lipid bilayer: in the area of the methylene groups of phospholipids near the centre of lipid bilayer and in the center of lipid bilayer. The suggested fluorescent probes can be used to monitor the changes of physico-chemical properties in different regions of lipid bilayer under the action of the cryoprotectants and to determine optimal concentrations of cryoprotectants for the low-temperature storage of cells.
Keywords: Fluorescent Probe; Human Erythrocyte Membrane; Cryoprotectants; Glycerol; 1,2-Propanediol