Physics, Chemistry and Applications of Nanostructures

The following sections are included:

• FOREWORD

• CONTENTS

A versatile method to modify the electronic structure and add functionalities to graphene is to bind foreign atoms to the hexagonal carbon lattice. We studied the room temperature chemisorption of oxygen atoms on graphene grown on Ir(111) by using high resolution X-ray photoemission and absorption spectroscopies to determine the adsorption configuration and the chemical structure of the oxidized graphene

The characteristic photonic, electronic, and acoustic functions of quantum-sized nanosilicon are presented along with the exploration of the device applications. Based on the band gap control by appropriate oxidation, the luminescence band can be tuned from red to blue. In heavily oxidized samples blue phosphorescence appears. Nanosilicon also exhibits an avalanche photoconduction effect. Other possible applications of nanosilicon are ballistic electron emitters and thermo-acoustic sound emitters.

The inhomogeneous strain field with Keating interatomic potential, hole energy calculation with nearest neighbor tight-binding single-particle Hamiltonian with the sp3 basis and the electronic energy levels calculation with solving three-dimensional effective-mass Schrödinger equation were used to study dense array of Ge quantum dots in Si. The enlargement of electron binding energy takes place in multilayer Ge/Si structures with vertical stacking of Ge islands due to accumulation of strain energy from different dot layers in a stack and increase of the potential well depth. In strained dots the change interdot distances causes crossing between the hole energy levels corresponding to bonding and antibonding orbitals. The enhancement of oscillator strength of the optical interband transition in type-II QDs occurs, depending on the interdot separation with peak at 3 nm.

The effect of the exchange energy variation in weakly ferromagnetic alloys on the superconductive resistive transition of superconductor/ferromagnet/superconductor (S/F/S) trilayers is studied. Critical temperature, T_c, and resistive transitions versus the F-layer thickness, d_F, have been analyzed in Nb/Cu_0.41Ni_0.59/Nb and Nb/Pd_0.81Ni_0.19/Nb trilayers. We show that T_c(d_F) dependence is sensitive to magnetic inhomogeneities in the F-layer for d_F corresponding to the thickness range where the π-superconducting state is established.

The lifetime of the second-order population of a fully inverted inhomogeneously broadened ensemble of quantum dots (QDs) is investigated. It is assumed that a planar structure of two-level QDs is initially non-resonantly excited by a pump laser pulse. After a delay time τ, the QDs are resonantly probed by laser pulse. Calculations using the master equation approach show that the lifetime of the second-order population is proportional to the QD density which is resonant with the probe laser spectrum.

A model of thermal formation of variable resistivity conducting nanowires during dielectric breakdown of HfO₂ in a meta/insulator/semiconductor structure is proposed. Local heating induced reversible and irreversible phase transitions along grain boundaries in the insulator are considered to be responsible for the change in the resistivity of the structure. The heat wave has been estimated to propagate in HfO₂ with the speed of (0.5-2)×10⁵m/s.

The propagation of Rabi waves in one-dimensional quantum dot chain interacting with the wave beam with a spatially inhomogeneous amplitude was investigated. We demonstrate that the reflections of Rabi waves and their mutual transformations at the field inhomogeneities are possible.

The Usadel equations for S/F multilayer structures are solved exactly by matrix method taking into account the paramagnetic and spin-orbital scattering effects.

A new method for simulation of polymers in nanoconfied geometries is presented. The temperature and the parallel component of pressure are kept fixed and the distance between confining surfaces is varied to keep the parallel component of pressure equal to the bulk pressure. Some static and dynamic properties of polyamide-66 have been calculated and discussed. Polymer molecules can form organized structures near the surfaces, causing a considerable slowdown in dynamic properties of the polymer.

Using Linblad equation for a density matrix we analyze theoretically the dynamics of a spatially inhomogeneous interacting polariton system, where energy relaxation and decoherence are provided by the interactions of polaritons with acoustic phonons.

We consider effective interactions in a 2D hybrid polariton-electron system and calculate dispersion of elementary excitations accounting the spin degree of freedom of the particles and calculate the spectrum of the elementary excitations of this system.

We have investigated the dynamic behavior of magnetic domain walls in ferromagnetic L-shaped nanowires under external magnetic field. By means of micromagnetic simulation we have observed dynamic characteristics of the domain walls with variation of nanowire thickness. The results show that the domain wall propagation depends on the demagnetizing field at the nanowire surface.

The theoretical arguments presented in this paper have shown how the distribution of the electrostatic potential V_j(x,U) in semiconductor-vacuum-metal nanostructure changes with an applied voltage. The finiteness and continuity of V_j(x,U) at the surfaces are saved through the formation of the double electric layer due to the change of the charge densities at the interfaces according to the contact potential ΔΦ and U. The obtained distribution of V₁(x,U) in the semiconductor is compared to the known quadratic law for Schottky barriers.

Tip rounding and the consequent effective pressure distribution at the apex of a nano-indenter tip violate the basic assumptions of the equations employed to determine the elastic modulus. The consequences of this violation are especially severe in the estimation of elastic modulus of submicron thickness films. A new analytical model that relies on an accurate strategy for determining the tip radius and tip area function of the tip is proposed to account for the effect of tip rounding. The model verified experimentally on a submicron SiO₂ thin film grown over silicon provides good results.

Magnetization and persistent currents of the superposition of parabolic quantum dot and inverse parabolic antidot in uniform magnetic field are calculated as functions of the distance ρs between their extrema. A transformation from the ideal Volcano disk at ρ S =0 to the quantum dot case for the large shift distances is revealed and discussed.

We discuss mechanical characteristics of single-wall carbon nanotubes. From them the elastic constants (elastic modulus, flexural modulus, torsion modulus) are selected as being most important for a use in mechanical, chemical and biochemical nanosensors and, in particular, in various versions of "electronic nose" (e-nose).

Advanced mathematical model of carbon nanofibre growth was developed. For the first time it takes into account the huge release of energy related to conversion of carbon atoms from a gas phase to solid one. Additionally, melting was proposed as a physical mechanism of shaping of catalytic nanoparticles.

We present the results of experimental investigation of the effect of single-wall carbon nanotubes functionalized with carboxyl groups on the isothermal elastic modulus of water in a wide range of pressures and temperatures.

A carbon nanostructure composed of an array of vertically aligned carbon nanotubes (CNTs) and a planar graphite layer (PGL) located at the top of the array has been fabricated by the injection CVD method. CNT-PGL structure was investigated by scanning electron microscopy and Raman spectroscopy. Raman spectroscopy analysis performed both on CNT-PGL and single PGL showed that PGL structure is similar to turbostratic graphite and most probably consists of disordered and randomly arranged graphene sheets. The calculated in-plane crystallite size of single PGL was 5.2 nm.

To predict the growth mechanism of carbon nanotubes (CNT) upon nickel catalyst, we have performed a series of large-scale DFT-LCAO interface calculations. When using the CVD method for CNT synthesis, carbon adatoms appear upon the nickel catalyst surface due to dissociation of carbon-hydrogen molecules (e.g., CH₄). We have started with the 2D models of molecular adsorption upon smooth and nanosctructured Ni(111) substrate. As a next step, we have simulated the C/Ni(111) interface, where carbon adatoms initially form flat carbon nanoflakes. Association of the adsorbed carbon atoms upon the catalyst surface precedes further swelling of the (C_n)_ads islands after appearance of pentagonal defects within a honeycomb sheet which are more probable upon the catalyst surface containing either defects or nanoclusters. Thus, nanoflakes can be gradually transformed into nanotube embryos (in the form of semi-fullerenes), and finally into capped CNTs with either armchair or zigzag chirality.

The technology for the formation of 2D-ordered vertically-oriented carbon nanowire arrays in porous anodic alumina matrices with titanium metal oxide nanocontacts to a silicon substrate has been developed. The investigation of the morphological feature and the element composition was carried out by a microprofiling technique and the Auger electron spectroscopy. The current-voltage characteristics of the fabricated 2D-ordered carbon nanowires arrays were measured in forward and reverse directions also under the influence of electromagnetic radiation. The mechanism of titanium metal oxide contact as well as the electromagnetic radiation influence on the I-V characteristic is discussed.

Optical properties (refractive index and extinction coefficient in the wavelength range of 400-1100 nm) were derived for thin fullerite films (C₆₀, C₇₀), evaporated on thermally oxidized silicon substrate and overcoated with nanosized metal layers (Bi, In). Annealing of the samples (up to 300 °C) results in variations of the optical properties depending on the type and thickness of the metal nanolayer.

Investigations of dispersion interactions in systems with FCC fullerite by a direct summation of discrete atom-atom interactions using a Lennard-Jones potential are presented. First, the interaction between two C₆₀ fullerenes in 19 principal orientations as a function of the separation has been calculated. Then a weighted average potential was used to determine the lattice parameter and a number of physical properties of the fullerite crystal. A modified Buckingham equation as an excluded volume expression was then proposed and evaluated for the fullerite-fullerene and fullerite-other molecule interactions. This equation revealed a highly accurate descriptive ability, when compared to experiment.

Diamond hosting nitrogen-vacancy (NV) color defect centers is the only solid state system in which a single spin addressing, initialization and readout can be implemented at room temperature. Quantum chemistry simulations of the diamond surface influence on the NV center spin properties are presented. We are discussing perspectives of new field of single NV center application for implementation of the single-spin magnetometry promising to achieve high spatial resolution, imaging speed and sensitivity.

Molecular orbital calculations (at the PM3 level) of nitrogen substitution impurity in diamond (P1 center) have been performed. Stationary states of nitrogen atom in the diamond lattice have been determined and the reaction coordinate for transitions between these states has been calculated. An interpretation of the maser effect in P1 center has been proposed.

We report on the first attempt to develop an effective ionizing shielding material on the basis of thermally stable phosphates widely used in aerospace applications filled with the micro-sized boron compounds and carbon nanotubes.

Geometrical models for zigzag and armchair bare boron nanotubes are proposed assuming that (i) all atomic sites are placed at the same cylindrical surface; (ii) all atoms are 6-coordinated; and (iii) all B-B bonds lengths are equal. Explicit expressions are obtained for tubes radii, their one-dimensional lattice constants, atomic sites and inter-site distances.

Catalyst-free growth of boron nitride nanotubes and whiskers is achieved in a quartz tube of an optical furnace in the flow of dried and purified nitrogen. Electron-diffraction analysis using a scanning and transmission electron microscopy technique indicates that the nanotubes are covered by a polycrystalline shell. XRD analysis shows only boron nitride components while energy-dispersive X-ray spectroscopy (EDX) demonstrates the presence of boron and nitrogen as well as oxygen in whiskers.

Molar binding energy of isolated boron nitride achiral nanotubes are found by the first principles calculations to oscillate in the range of small radii. The structures (1,1), (3,0), and (4,0) are predicted to be the most stable. Stable sequences of nanotubular layers in multi-walled boron nitride nanotubes are suggested.

The compressive buckling of boron nitrides nanotubes (BNNTs) has been studied using molecular dynamics (MD) simulations. We have used the Lennard-Jones pair potential to characterize the interactions between non-bonded atoms and harmonic potentials for bond stretching and bond angle vibrations. Results of the MD simulations are used to characterize the critical uniaxial compressive buckling loads of BNNTs and indicate that the critical buckling loads increase for larger nanotubes.

The ab initio and semi-empirical computer simulations of the optical absorption and the emission energies of the silicon nanoclusters (1-3 nm) embedded in alumina matrix and the study of their dependence on the cluster size were performed. It was shown that the cluster structure relaxation of the excited state took place mainly inside of the silicon cluster and which in its turn led to the significant space shift of one of the silicon atoms from its ground state position. The presence of various Al₂O₃/Si interfaces besides those with the silanone bond does not significantly influence on the properties studied.

By means of first principles calculations we show that both uniaxial and radial strains provide a feasible tool to tune band-gaps in silicon nanowires with the <001>, <011>, <111> and <112> axes. The most promising results are obtained for the <011>-oriented nanowires which display a 35 % reduction in the band gap under 5 % tensile uniaxial strain, that opens a way to different device applications based on silicon quantum dot or quantum well structures.

Quantum-chemical modeling of structural stability of Si nanowires is presented. Formation and diffusion of intrinsic point defects in the nanowires have also been studied. The significant decrease of the Frenkel pairs formation energy in nanowires as compared with bulk crystalline silicon was found.

One-dimensional photonic crystal microcavities formed from porous silicon layers were analyzed theoretically for different angles of incidence and different polarization of light. The effect of minimal reflectance at Brewster angle was observed for the reflection of the structures for p-polarized light. The Frehnel fringes were strongly suppressed and the microcavity resonance was enhanced at the angle near the Brewster one. The experimental spectra demonstrate more complex behaviour of the reflectance of the porous-silicon based multilayer structures which can be explained considering the polarization-dependent properties and the real feature light scattering and absorbance of porous silicon layers.

An increase of the conductivity in the low temperature range has been observed for Si/Mg₂Si/Si(111) heterosystems with embedded Mg₂Si nanocrystals (NCs) and/or two-dimensional (2D) Mg₂Si layer. The models of conductivity processes through the silicon layer with embedded Mg₂Si NCs and 2D Mg₂Si layer have been proposed.

Multilayer structures (up to 15 layers) with β-FeSi₂ nanocrystallites (NCs) buried in silicon crystalline lattice were grown by repetition of reactive deposition epitaxy (RDE) or solid phase epitaxy (SPE) of thin iron film on Si(100) or Si(111) substrates and by silicon molecular beam epitaxy (MBE) (100-200 nm). Cross-section high resolution transmission electron microscopy (HR TEM) images and Raman spectroscopy data proved that NCs formed in the silicon matrix had the structure and optical properties of β-FeSi₂. Significant photoluminescence (PL) signal at 0.8 eV was observed for all samples.

The density, phase composition and parameters of fine crystalline structure (microstrains, density of dislocations, and the sizes of areas of coherent dispersion) have been investigated for Si₃N₄ samples, sintered from nanocrystalline α-Si₃N₄ powder at the pressure of 4 GPa and temperatures of 1300-1850 °C. The most intensive grain growth occurs after densification and phase α→β transformation in silicon nitride.

The influence of size effects on the growth rate of Si nanowhiskers is studied theoretically. It is shown that the dependence of the sticking (condensation) coefficient of Si atoms on the Au-Si droplet size can influence the growth rate of nanowhiskers.

The X-ray absorption near edge structure (XANES) spectroscopy investigations of the electronic structure with the use of synchrotron radiation were performed for surface nanolayers of the single crystalline silicon wafers subjected to low-energy hydrogen and argon plasma treatments. It was shown that the surface silicon oxide nanolayer with a thickness greater than native silicon oxide is formed as a result of such treatment. At the same time, in the investigated wafers the surface layers of a few nanometers contain elementary silicon in a disordered (amorphous) state. Possible clusterization of the surface layers was considered to be a resultant of the plasma treatment.

Disappearance of divacancy (V₂) and trivacancy (V₃) complexes upon isochronal and isothermal annealing of electron irradiated Si crystals has been studied by means of deep level transient spectroscopy. The annealing studies have shown that the V₂ and V₃ defects are mobile in Si at T > 200 °C. In oxygen-rich material they are trapped by oxygen atoms resulting in the appearance of V₂O and V₃O defects. The activation energies for diffusion of the V₂ and V₃ centers have been determined.

We have studied optical properties of a novel type of hybrid nanostructures that combine CdTe colloidal quantum dots with organic dye molecules in a J-aggregate state. The QD/J-aggregate system shows the broadband absorption in visible and ultraviolet part of the spectrum typical for the quantum dots, along with the narrow emission linewidths characteristic of the J-band emitters (~15 nm full width at half-maximum (fwhm)). PL spectroscopy and PL lifetime studies demonstrated the efficiency of the energy transfer to be about 91 %.

Here, we discuss energy relaxation dynamics for nanoscale self-assembled porphyrin triads based on non-covalent two-fold extra-coordination of the porphyrin free-base extra-ligand with Zn-octaethylporphyrin chemical dimer (ZnOEP)₂Ph, (donor, D), while the last, in its turn, may contain covalently linked electron acceptors, quinone, Q or pyromellitimide, Pim. Based on picosecond time-resolved spectroscopy in solutions and theoretical estimations it has been proven that the deactivation of the dimer excited S₁ state is caused by two competing processes (energy migtation, EM, and photoinduced electron transfer, PET). In contrast, the porphyrin extra-ligand relaxation dynamics is governed by the effective superexchange PET to a spatially separated electron acceptors Q or Pim, where the dimer (ZnOEP)₂Ph plays the role of quantum bridge.

We examined optical effects associated with a chemical substitution of Cd ions by Hg(II) in CdSe colloidal quantum dots in a toluene solution. At mild conditions Hg(II) benzoate reacts with CdSe core quantum dots stabilized with oleylamine resulting in ternary Cd_xHg_1-xSe nanocrystals. We observed different optical absorption and photoluminescence response depending on whether hexagonal (wurtzite) or cubic-type (sphalerite) CdSe quantum dots were taken to the reaction.

Using both bulk and single molecule/single particle experimental data being obtained for "semiconductor CdSe/ZnS quantum dot-organic dye molecule" nanoassemblies we discuss the role of interface properties, electron wave function tunnelling and exciton-phonon interactions as possible reasons for the photoluminescence quenching dynamics in these nanoobjects.

We studied the photoluminescence (PL) properties of colloidal nanocrystals of cadmium selenide and copper doped nanocrystals of cadmium selenide with the mean size of 3-4 nm. The experimental results revealed nonmonotonic dependence of the PL peak position as a function of the excitation photon energy varied from 2.41 to 3.68 eV. This effect was explained by considering both the size distribution of nanocrystals and the specific spectral dependence of the absorption coefficient. The PL properties of copper doped quantum dots are found to be different for those of undoped ones. In particular, the PL spectrum of copper doped quantum dots exhibits a broad peak with the maximum at 1.5 eV and the excitonic band of PL is absent. PL kinetics is found to vary from biexponential to the stretched exponential relaxation after doping quantum dots with copper. The observed modification of the PL spectra and lifetimes was explained by the transformation of luminescent centers in QDs after doping with copper.

The phase transfer reaction was used for the surface modification of CdSe/ZnS nanocrystals (NCs) with cysteamine. During this reaction NCs move from the nonpolar chloroform medium to the polar aqueous solution and possess surface cationic charge due to ionogenic aminogroups of the cysteamine moiety. The optical density (OD) and photoluminescence (PL) spectra of cationic NCs experience long-wavelength shifts ca. 98 meV in aqueous solution compared to the chloroform one. PL spectra of the cationic NCs also experience inhomogeneous broadening. The spectral changes are discussed as a result of the Stark effect induced by local ionic charges on the NCs surface. In assumption of the local electric field effect the measured Stark spectrum can be presented as a difference between NCs OD spectrum in water (local field-on) and chloroform (field-off). The modelling of the Stark spectrum is performed.

The dependence of the photo-induced processes in cadmium selenide nanocrystals under external electric fields on the excitation photon energies has been established. The relationship between the photo-induced processes of photoluminescence enhancement and quenching in quantum size cadmium selenide nanocrystals under external electric field has been demonstrated. The mechanism of photoluminescence quenching and the mechanism of excitation photon energy influence on photo-induced processes are discussed.

A TEM study of GaAs nanoislands grown on (001) Si substrate by the droplet epitaxy technique is presented. The nanoislands turn out to be monocrystalline in perfect epitaxial relationship with Si. By X-ray microanalysis in the TEM it is also seen that the islands are stoichiometric. TEM images of the moiré fringes revealed the presence of dislocations at the nanoislands suggesting strain relaxation.

New empirical technique for calculation of refractive index of laser diode active region is presented. It is based on the numerical analysis of far-field patterns of tilted-wave lasers consisting of two coupled waveguides. The approach has been used for calculation of mean refractive index of active region based on self-organized InAs quantum dots.

In_0.4Ga_0.6As/GaAs heterostructures with the chains of quantum dots were studied. The anisotropy of electrical properties of the structures in the temperature range of 77-150 K was found by measurements of dark current. The dark current conductivity temperature dependence can be described by the Shklovskii-Efros law of variable range hopping conductivity. The energy states of the heterosystem were investigated by the lateral photocurrent and photoluminescence spectroscopy measurements.

Numerical calculations of the valence band and conduction band size quantized levels in a strained p-Al_xGa_1-xAs/GaAs_1-yP_y/n-Al_xGa_1-xAs (y = 0.16) double heterostructure were performed for different external uniaxial compressions along [110] direction. The results explain the nonlinear character of the photon energy shift and electroluminescence intensity increase that were experimentally observed in these structures under uniaxial compression up to 5 kbar.

We present a theoretical investigation of the spin gap system Sr₃Cr₂O₈ based on density functional theory calculations. We show that inclusion of electron correlation arising within the Cr-3d shell is essential to understand its spin-singlet magnetic ground state.

Ab initio quantum mechanical modeling is used to describe glass-forming tendencies in As-S chalcogenide glasses. The main building blocks in these glasses are shown to be the corner-sharing optimally constrained network-forming clusters AsS_3/2.

We have investigated the magnetic domain wall propagation and its pinning/depinning behavior in notched ferromagnetic nanowires under various temperatures by means of micromagnetic simulation. We have observed that thermal fluctuations play a significant role in the domain wall depinning field in the nanowires.

Characteristic features of formation of PbZr_0.54Ti_0.46O₃ compound in etched swift heavy ion tracks obtained by irradiation of Si/SiO₂ structure by ¹⁹⁷Au²⁶⁺ ions and investigations of dielectric properties of the obtained structures are considered. PbZr_0.54Ti_0.46O₃ compound is obtained as a result of optimization of thermal treatment of film structures with identical to the sputter target composition, being ion-beam sputtered on Si/SiO₂ substrates. During the study of temperature dependence of Si/SiO₂ (PbZr_0.54Ti_0.46O₃) structure at various frequencies (5×10³ Hz – 8×10⁵ Hz) its dispersion is obtained.

Annealing of nanostructured Sr₂FeMoO_6-δ films in an evacuated quartz tube results in variation of concentration of antistructural defects [Fe_Mo], [Mo_Fe] and spin polarization degree. The films possess low magnetization and large magnetic inhomogeneity.

An interaction of gold nanoparticles and indium oxide under formation of Au-In₂O₃ nanocomposite prepared by the sol-gel method has been studied. It was shown by EPR, DSC/TG and optical spectroscopy that the chemical interaction between In₂O₃ and Au is accompanying by the transfer of electron density and the (Au⁰_n)Au^(3-δ)+ clusters can be formed under heating of the nanocomposites.

Quantum chemical calculations of the pyrolyzed polyacrylonitrile with carbon and nitrogen vacancies have been performed. Formation of these defects results in the noticeable changes of the energy characteristics and effective charge distribution.

Electrostatic force microscopy (EFM) represents a versitile tool for the characterisation of electric and dielectric structures at nanoscale which can be employed to provide charge distributions associated with such nanotopologies. EFM-phase profiles show only the variation of electrostatic force which is strongly influenced by the surface conductivity of nanostructured arrays providing improved definition compared to conventional AFM. Here we apply it to carbon nanochannel arrays embedded within polyimide dielectric matrices.

High energy irradiation impacts on the structure and properties of metallic nanomaterials, steels and compounds. The different behavior of nanostructured bulk materials and isolated nanoparticles in inert matrices is considered. Some less studied and unsolved problems are emphasized.

Carbon nanotubes are proposed as an innovative material for future nano-interconnects. Here a circuit model is presented to describe the electrical behavior of interconnects made by bundles of carbon nanotubes. The model is derived within the frame of the transmission line theory, starting from a semi-classical description of the carbon nanotube electrodynamics. The model includes effects related to chirality, size and temperature, hence it is suitable to analyze real-world applications, where carbon nanotube interconnect technology must meet conventional CMOS one. Case-studies are carried out referring to typical interconnects for the future 22 nm-node technology.

We show that an experimentally attainable magnetic field applied along the axis of a metallic carbon nanotube not only opens the gap in the nanotube energy spectrum but also allows optical transitions, which are forbidden in the absence of the field. Possible terahertz applications of this effect are discussed.

The transverse electric field which appears in carbon nanotubes spontaneously by applying of a strong electric field in the presence of a magnetic field was calculated. The effect can be associated with the non-equilibrium state of the electron subsystem in carbon nanotubes. The dependence of the spontaneous field on the magnetic field was studied.

We present an effective medium model of arrays of single-wall metallic carbon nanotubes (CNTs), based on the theory of wire media. The model takes into account both quantum properties of CNTs and electromagnetic interaction between carbon nanotubes. We discuss slow electromagnetic waves propagating along a finite-thickness CNT slab where carbon nanotubes are aligned in the plane of the slab.

A possibility of creation of photonic microdevices is shown based on coherent nonlinear-optical energy exchange between ordinary and backward electromagnetic waves in nanostructured negative-index metamaterials.

Electron diffraction is one of the very few techniques available today for resolving the atomic structure of carbon nanotubes. The aim of this short review is to explain why and how this is possible, while putting emphasis on pedagogy rather than on exhaustivity.

In order to overcome disadvantages of nowadays microtechnology, the miniaturization of electronic devices, a high integration level and the increase of the operation frequencies and power density are required, including the use of adequate materials and innovative chip interconnects. Due to their unique physical properties, especially due to a ballistic mechanism of conductivity, carbon nanotubes (CNTs) attract permanently growing technological interest, for example, as promising candidates for nanointerconnects in a high-speed electronics. New possibilities for modern nanolectronics are opened with a novel 'marginal' forms of graphene – nanoflakes (GNFs) and nanoribbons (GNRs), which analogously to CNTs demonstrate a lossless ballistic mechanism of conductivity. Graphene nanointerconnects are also important for nanotechnology. Full integration of graphene into conventional device circuitry would require a reproducible large scale graphene synthesis that is compatible with conventional thin film technology.

A linear augmented cylindrical wave method is developed for calculation of electronic structure of ideal and doped carbon nanotubes. The method was applied to determine the band structures and densities of states of the chiral and achiral, semiconducting and metallic both pure and boron and nitrogen doped carbon tubules.

The infrared absorption spectra of DNA films with embedded single wall carbon nanotubes (SWCNT) were investigated. The experimental data for DNA-SWCNT film show an enhancement of DNA infrared absorption in comparison with absorption in the reference DNA film of the same thickness. The possible mechanism of the absorption enhancement is local field effect in the near-field zone of finite-length metallic SWCNTs.

The dielectric properties of polymethyl methacrylate (PMMA) filled with multiwalled carbon nanotubes were studied in the terahertz frequency range. An oscillator law was found to describe successfully the decrease of the composites transmission with frequency.

The non-ohmic current-voltage (I-V) characteristics and the temperature dependence of the resistance of the epoxy/SWCNTs composites in the temperature range of 2-300 K were investigated. Their electrical properties can be described in the frame of a heterogeneous model for conduction. The transmission, reflection and absorption spectra were measured in Ka-band. The epoxy/SWCNTs composites demonstrate high electromagnetic shielding effectiveness: the average power transmitted through the samples is about 30 %.

Two-dimensional problem of electromagnetic field propagation in an array of carbon nanotubes in the presence of an external high-frequency field was considered. The derived effective equation has the form of a classical Sine-Gordon equation. The system in an external homogeneous electromagnetic field with its period much shorter than the characteristic pulse length was studied.

A dispersion equation for electron beam instability in graphene is derived and investigated. Graphene (single layer, bilayer and multilayer) operating as a Cherenkov-type emitter is discussed. Increments of electron beam instability leading to stimulated radiation are calculated.

Density functional theory calculations have been used to investigate possible mechanisms of hydrogen-induced decoupling of graphene from SiC(0001). The results suggest that hydrogen atoms reach SiC surface through extended defects in graphene layers and then migrate and passivate bonds on the SiC surface.

Scattering of electromagnetic fields by a finite-length dielectric nanotube covered by a thin metal layer was theoretically investigated. The dispersion characteristics of the surface plasmons in the nanotube were obtained. The axial polarizability of the nanotube was calculated and the pronounced resonance lines in the polarizability spectra were demonstrated. The resonance frequencies depend both on the nanotube length and on the thickness of the metal layer.

The deformation influence on electromagnetic response of carbon nanotube based polymer composites was theoretically modeled and experimentally investigated in Ka-band.

We report on the synthesis of optically high quality cadmium phosphide quantum dots with emission wavelength maxima across the visible red to the NIR region of the spectrum. Photoelectrochemical investigations reveal that electrodes derivatized with the cadmium phosphide quantum dots show that an optical response and photocurrents of several nA/cm2 can be obtained upon illumination by an LED.

The quasi seeded growth approach is investigated as a possibility to optimize hot injection methods in order to provide high quality CdSe and PbSe quantum dots. This technique is reported here as a novel means by which up-scaling may be implemented.

A novel synthesis method is presented to fabricate bifunctional magnetic nanoparticles with a varying thickness shell of cadmium sulfide. The morphology and composition of the dispersed phase and optical properties of the obtained colloids were studied by UV-vis and photoluminescence spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM).

Ultrasmall colloidal CdS and CdSe nanoparticles (~ 2 nm) with narrow size distributions were synthesized and stabilized by polyethylenimine. The quantum dots revealed the structured absorption bands with excitonic maxima and the broad-band efficient photoluminescence in the visible spectral range. Both colloids exhibited the high electrocatalytic activity in the potential range of hydrogen evolution. CdS QDs anodic oxidation was characterized by a single anodic peak, while CdSe QDs showed two anodic peaks. The additional peak at 250 mV below the main peak was attributed to selenium related surface defects.

Nanoparticles of the CuInSeTe solid solution were synthesized within the silicate glass. Studies of optical features of the glasses for various CuInSeTe concentrations and after the secondary heat treatment argue on possible phase transformation of the nanoparticles.

PbSe nanoparticles were grown in the borosilicate glass matrix by the controlled thermal treatment. Formation of PbSe nanoparticles of different sizes allowed shifting the first excitonic absorption peak position from 1000 nm to 2200 nm. Optical spectroscopy, small-angle X-ray scattering and X-ray diffraction were used for characterization of these glasses.

Local anodic oxidation (LAO) by atomic force microscopy (AFM) was used to generate silicon oxide nanostructures on alkyl monolayer terminated silicon. These structures are selectively functionalized by anchoring optically active molecules through a chemical bottom-up approach. First silane molecules with amino head-groups are bound from solution on top of the silicon oxide as a linker layer. In the second wet-chemical step fluoresceinthioisocyanate (FITC) reacts with the amino groups and thus is bound covalently to the nanostructure. The successful binding was verified by AFM and spectrally resolved optical investigations.

Magnetite nanoparticles/polymer composite films were formed on solid substrates by the Langmuir-Blodgett (LB) technique, allowing precise control over the film thickness and structure. Roll-to-roll LB processing can be used for continuous magnetic films formation.

A possibility to control the structure, size and morphology of iron oxide nanoparticles prepared by the sol-gel approach has been studied. Two procedures were used to obtain γ-Fe₂O₃ and Fe₃O₄ samples: i) spray pyrolysis of Fe^II + Fe^III salt solutions or Fe₃O₄·nH₂O colloidal solutions; ii) chemical precipitation of Fe^II or Fe^II + Fe^III hydroxides with subsequent peptization of the sediment and drying. SiO₂ sol, chloride ions and surface-active agents (surfactants) were added into starting solutions to modify the surface of iron oxide nanoparticles and to control their size. Structural features of the samples were examined by XRD, TEM and SEM, IR spectroscopy and Mössbauer spectroscopy.

Porous materials with a controllable pore shape and size distribution are of particular interest in catalysis, filtration or selective adsorption and can serve as building blocks in photovoltaic systems or fuel cells. Here, we report on the ultrasound driven formation of mesoporous metallic based structures from metal plates and particles in aqueous media. A systematic investigation of ultrasound effects on various types of metals reveals cavitation-induced oxidation of metals to be one of the principal factors of the process. We use this finding to expand our approach to alloys demonstrating that mesoporous nanocomposites can be formed through the one-step process. Beyond the specific examples, the findings provide guidelines for formation of hybrid Al/polypyrrole nanocomposites and active surfaces.

Polymer-metal nanocomposite films have been fabricated from aqueous solutions of poly(3,4-ethylenedioxy thiophene) + polystyrenesulfonate (PEDOT:PSS) and gold or silver colloids. The solutions and nanocomposite films have been characterized by scanning transmission electron microscopy, optical absorption spectroscopy, conducting AFM, and conductivity tools. The insertion of gold nanoparticles into PEDOT:PSS results in almost two orders of magnitude increase of bulk conductivity and growth of sensitivity to adsorbed oxygen. The conducting AFM revealed the gradual nonlinear change of the current and different direct and back scans for the nanocomposite films as compared with pure polymer films.

Electroless nickel plating on silicate glass was studied. It has been shown that substitution of aqueous SnCl₂ sensitization solution for Sn(II) containing organosol enhanced the adhesion of nickel films and their thickness (up to 3 μm), enlarged the rate of deposition (about 6 times) and provided the films with fine-grained and dense microstructure. The organosol increases the stability of sensitizing solutions and favourably affects nanostructural morphology of the sensitized surface and its catalytic activity.

A simple single-step synthesis of gold nanoparticles through reducing chloroaurate ions (AuCl₄^-) with sodium borohydride (NaBH₄) in the presence of sodium folate, glutamic acid or sodium oleate as stabilizers has been developed. The structure of gold nanoparticles and optical properties of the prepared hydrosols were characterized by UV-visible spectroscopy, IR-spectroscopy and transmission electron microscopy. It was shown that gold nanoparticles capped by sodium oleate were instable and form aggregates on aging, while the nanoparticles capped by folate and glutamic acid were stable at ambient conditions.

The novel class of stabilizing ligands, tetrazole-5-thiols, has been applied for the direct colloidal synthesis of palladium nanoparticles. Morphology of the synthesized particles and some properties were determined by TEM, FTIR and UV-visible spectroscopy, thermogravimetric analysis.

We report on fabrication of CaTiO₃:Dy³⁺/Al₂O₃ nano-system through the one-step organic-free colloidal technique. SEM, XRD and PL methods were used to investigate the structural and luminescent properties. Polycrystalline CaTiO₃:Dy³⁺/Al₂O₃ nano-system after the moderate heat treatment in air (900 °C, 1 h) shows single narrow red emission band under UV excitation instead of the emission typical for Dy³⁺ due to the blue-green-yellow transition. We compare structural and spectroscopic behavior of this system with the data for SrTiO₃:Dy³⁺/Al₂O₃ prepared by the same technique.

Ultradisperse CuI powders and CuI nanoparticles in the nanocomposite GeO₂-CuI films were obtained as possible doping materials for solar cells. For CuI powders and GeO₂-CuI films the luminescence bands at λ_max ≈ 420 and 720 nm were established. The relative intensity of the bands varies depending on the morphology and particle size of CuI. Processing of the GeO₂-CuI films at 300 °C in an inert atmosphere leads to decrease of the intensity of the band edge luminescence peaked at 420 nm and increase of the recombination luminescence band at 720 nm.

Thermal characteristics of silver nanocomposites on the basis of galactose containing polysaccharides have been studied by thermogravimetric analysis. The nanosized metal component shows significant influence upon thermal destruction activation energy and thermal stability of the nanocomposites.

An ability of chitozan to bound and keep metal ions due to many free aminogroups was used for fabrication of the composite film based on chitosan/organosilan mix and Au nanoparticles. It was demonstrated by optical methods that the use of chloroauric acid for this aim is more effective than the use of gold colloid solutions.

Complex metallic alloys (CMAs) are new possible candidates for reinforcing agents with excellent technological potential. β-Al₃Mg₂ belongs to this new category of intermetallics. β-Al₃Mg₂ nanoparticles were synthesized by mechanical milling (MM) of pre-alloyed CMA intermetallic ingot in attritor ball mill. Then different amounts of CMAs nanoparticles varied from 0 to 20 % (by weight) were added to aluminum matrix powder. Consolidated samples were prepared by hot pressing of blended composite powder. The results confirmed the formation of uniform distributed reinforcement in the nanocomposites with finer microstructure by addition of the CMA reinforcement.

Tribological characteristics of mono- and multimolecular films formed by surface-active compounds such as triacontanoic acid (TA), behenic acid (BA), polyvinylpyridine (PVP) formed on silicon surface by Langmuir-Blodgett (LB) technique were studied. Wear stability in friction of TA, BA and PVP monomolecular films was compared with the stability of coatings based on fullerene nanoparticles in PVP matrix, with the monolayer of polyallilhydrochloride (PAH), and with octadecyltrichlorosilane (OTS) chemisorbed film. Incorporation of fullerene nanoparticles in PVP matrix reduces the wear stability of the coatings. Wear stability of OTS film is higher than that of monolayers of polyelectrolytes and PVP film, but sufficiently lower than the stability of BA and TA ones.

Immersion displacement deposition of copper on porous silicon has been demonstrated as a technique for novel nanostructures fabrication. Copper/porous silicon electrical contacts to silicon, copper nanoparticles on porous silicon and copper porous membranes have been fabricated. Morphology, structural and electrical properties of these nanostructured systems have been studied by SEM, XRD and I-V characterization.

Silicon nanocrystals prepared by mechanical milling of crystalline or porous Si were investigated as sonosensitizers for biomedical applications. The porous Si powders consisted of particles with average sizes of 50-200 nm, which are agglomerates of nanocrystals with minimal sizes of 3-6 nm. The observed photoluminescence (PL) confirms the nanosizes of produced materials. In vitro experiments showed that simultaneous action of the nanoparticles and ultrasound could result in either the complete destruction of cancer cells or in their specific damages, which suppressed strongly the cell proliferation activity. This observation demonstrates perspectives of silicon nanoparticles as sonosensitizers in order to improve efficiency of the ultrasound therapy of cancer.

Two different growth modes of fabrication of Si nanowires were explored: vapor-liquid-solid growth and wet chemical etching. The morphology and structure of single crystalline nanowires with respect to their crystallographic orientation was analyzed by scanning (SEM) and transmission (TEM) electron microscopies and by electron backscatter diffraction (EBSD) in an SEM. The optical and optoelectronic characteristics of the different silicon 1D architectures were investigated.

Cleaning of Si wafers through kHz-frequency ultrasonic treatment in a water-containing bath is studied. The cleaning stages observed with varying treatment time are discussed. During the first 60-90 min, organic hydrocarbon contaminants can be effectively removed from the wafer surface. This is evidenced by the disappearance of organic-related absorption peaks and remarkable shortening of the photovoltage decay transients. At longer times, the subsurface crystalline quality is degraded and the wafer performance gradually deteriorates. The decay curves become the double-exponential profiles, developing fast initial decays and longer further decays. The latter is indicative of a subsurface trap generation. This is accompanied by the broadening of X-ray rocking curves. The likely origin of the presented effects is discussed.

Peculiarities of low-temperature fabrication of titania and zinc oxide nanostructures are presented. Application of such nanostructures in light and mechanical energy harvesting devices are discussed. Key technological parameters of nanocrystal formation are determined.

In close analogy with the catalytic growth of graphene over-layer on several metal surfaces we have grown a two-dimensional silicon sheet in a honeycomb lattice, i.e. in a graphene-like structure, which could be a silicene layer. Two atomic ball models of this silicon single layer accounting for the atomically resolved scanning tunneling microscopy images and the low energy electron diffraction patterns are presented.

Current applications of nanomaterials in biology and nanomedicine are considered. Nanomaterials provide an alternative method for detection of individual biomolecules, cell components and other biological agents. Several applications of nanomaterials for bioimaging, photodynamic therapy for cancer and as probes for flow cytometric analysis were demonstrated.

We have modified monolayer graphene sheet to oxidized graphene using the local anodic oxidation method by atomic force microscope. Graphene oxide was successfully formed in line and square shape at various bias voltages and scan speeds.

Laser and optical properties of green-emitting A²B⁶ heterostructures with five electronically-coupled (Zn)CdSe/ZnSe quantum dot active regions were investigated. New design of optical waveguide based on the graded-index ZnMgSSe/ZnSe superlattices results in the noticeable improvement of laser characteristics, in particularly, in the increase of the gain (ΓG₀=167 cm^-1) and internal quantum efficiency (η_i=70.1 %). The heterostructure with new design was optically pumped by the violet emission of a commercial InGaN laser diode and showed the improved laser performance comparing to a flat waveguide design. The maximum quantum efficiency and output pulse power in the green spectral region were as high as 10 % and 75 mW, respectively.

The porous titania growth during electrochemical anodization of titanium films and foils in the 0.1 M FNH₄ solution in ethyleneglycol at the electrolyte temperatures below 0 °C results in a smooth tubular structure with the tube diameters up to 300 nm. The growth rate was as high as 1.5 μm/min providing the structure similar to ideal packed hexagonal prisms with the film porosity less than 1 %.

Mechanical milling of the mixture of silicon and titanium nanopowders was observed to produce at room temperature nanostructured titanium silicide phases with a = 0.82671 nm, b = 0.48 nm, c = 0.85505 nm and a = 0.362 nm, b = 1.376 nm, c = 0.3605 nm. This mixture demonstrated ability for photodecomposition of water into hydrogen and oxygen. Its efficiency was found to be the best for the starting ratio Si:Ti=1:0.86.

Regular step arrays with different period on vicinal Si(111) were obtained by varying thermal annealing procedure in ultrahigh vacuum conditions. The step formation has been studied by scanning tunneling microscopy (STM), low energy electron diffraction (LEED) and Auger electron spectroscopy (AES) at room temperature. The deposition of Gd on stepped Si substrate demonstrates the anisotropic growth.

Films of Pd, Ni, and Ni-Pd alloy, deposited by pulsed laser ablation, have been investigated with transmission electron microscopy. It was established, that at alternate deposition of laser erosion plasma of Ni and Pd, films with metastable hexagonal (hcp) crystal lattice can be formed. After annealing these films acquire an equilibrium cubic (bcc) structure.

New nanocomposite TiZrAlN coatings were synthesized using dc reactive unbalanced magnetron sputtering. The critical concentration of Al, which ensures the structural change from substitutional solid solution on the basis of the (Ti,Zr,Al)N system to a nanocrystalline state, was established. The solid solutions with (111) preferred orientation are formed for low Al content (<5 at.%). At 5 at.%, the columnar growth is disrupted resulting in (002)-oriented fine-grained film. Above this threshold value, nanocomposite films with typical grain size of ~ 2 nm are revealed.

We have proposed a hydrothermal microwave route to fabricate highly efficient photocatalysts based on ZnO with functional characteristics better than commercial analogues based on TiO₂. We have shown that the heating rate of the Zn²⁺/hexamethylenetetramine reaction mixtures is the key factor determining the morphology and photocatalytic activity of ZnO.

The synthesis of nanosized mesoporous ceria powders by modified sol-gel technique and effect of cryotreatment by liquid N₂ of as-prepared sol on its morphological features were investigated. It was found that the increase of molar ratio N,N-dimetiloktilamine/Ce in the initial sols leads to the increase of ceria specific surface and decrease the content of micropores.

Nanocrystalline ceria solid solutions containing rare earths (Pr, Nd, Sm, Eu, Gd, Yb) in various concentrations (5, 10, 15, 20 mol.%) were synthesized via homogeneous hydrolysis of corresponding nitrates in the presence of hexamethylentetramine. It was established that the increase of concentration of dopants from 0 to 20 mol.% leads to considerable reduction of particles sizes (down to 4 nm) while the lattice parameter of solid solutions changes linearly according to the Vegard's law.

Nanostructures including β-MnO₂, Mn₃O₄ and MnO(OH) have been synthesized. Their electrochemical and catalytic properties were studied.

Electric resistance of an aluminium foil was used to monitor its temperature during anodization in the regimes providing porous alumina formation. Current densities higher than 100 mA/cm² were found to be accompanied by the sample heating several tens of degrees above the electrolyte temperature. Local heating of different regions in the forming porous nanostructured alumina was calculated to show considerable anisotropy of the effect.

We have investigated human mesenchymal stem cells by combined fluorescence microscopy and scanning force microscopy. The pulsed force mode for scanning force microscope was used to determine mesenchymal stem cells mechanical properties like local stiffness and adhesion.

Intravascular platelet activation was determined with scanning force microscopy (SFM) in patients with coronary heart disease. Algorithms are developed for evaluation of the total number of platelets in SFM images, the number of aggregates (consisting of several cells), the number of platelets in each aggregate and the number of platelets located separately.

We report on room-temperature operation of Si nanowires (SiNWs) based single-electron transistors (SETs) fabricated using conventional optical lithography. The SiNWs have a diameter of around 3 nm to 4 nm and different lengths ranging from 200 nm to 500 nm. Strong Coulomb oscillations are observed at room temperature. The oscillations are found to be more prominent for longer SiNWs. The results are interpreted in terms of the effect of SiNW length on the oxidation induced tensile strain, which in turn affects the barrier height developed in the SiNWs. It is concluded that SiNW length is a crucial parameter in the design of SiNW based SET devices.

We report a novel technique for the fabrication of planar-type Ni-based single-electron transistors (SETs) using electromigration induced by field emission current. The method is called "activation". It is demonstrated using arrow-shaped Ni nanogap electrodes with initial gap separations of 21-68 nm. Using the activation method, we are easily able to obtain the SETs by Fowler-Nordheim (F-N) field emission current passing through the nanogap electrodes. The F-N field emission current plays an important role in triggering the migration of Ni atoms. The nanogap is narrowed because of the transfer of Ni atoms from the source to the drain electrode. In the activation procedure, we defined the magnitude of a preset current and monitored the current between the nanogap electrodes by the voltage applied. When the current reached the preset current, we stopped the voltage. As a result, the tunnel resistance of the nanogaps was decreased from the order of 100 TΩ to 100 kΩ with increasing the preset current from 1 nA to 150 μA. The devices formed by the activation with the preset current from 100 nA to 1.5 μA exhibited Coulomb blockade phenomena at room temperature. Coulomb blockade voltage of the devices was clearly modulated by the gate voltage quasi-periodically, resulting in the formation of multiple tunnel junctions of the SETs at room temperature. By increasing the preset current from 100 nA to 1.5 μA in the activation scheme, the charging energy of the SETs at room temperature was decreased, ranging from 1030 meV to 320 meV. Therefore, it is found that the charging energy and the number of islands of the SETs are controllable by the preset current during the activation. These results clearly imply that the activation procedure allows simple fabrication of planar-type Ni-based SETs operating at room temperature.

A hybrid microresonator consisting of a thin silicon nitride membrane with a silicon column at its center is presented as a sensor for mass detection and gas analysis experiments. Its main benefit, compared to conventional microresonator geometries, e.g. cantilever and bridges, is the spatial separation of the detection path on the flip side of the membrane from mass loading experiments on the surface of the column. The influence of immersing gases on the resonant frequency shift of the hybrid microresonator at ambient conditions was studied experimentally and compared to a simplified model of a cantilever in an inviscid fluid. Furthermore, mass detection was performed depositing chromium onto the column as well as investigating its response at varying nitrogen pressure.

The fabrication and properties of metal-insulator-metal (MIM) capacitors and metal-oxide-semiconductor (MOS) memory structures using thin porous anodic aluminum oxide layers are described. The advantages of anodic alumina layers are the simplified fabrication processes, the CMOS compatibility, the room temperature processing and low cost of the material. Electrical characteristics comparable or better than the state-of-the-art devices were demonstrated for both sets of devices and are presented in detail.

A technique for fabrication of nanosized metal and anodic oxide films with improved optical features for displays and photonic devices is discussed. We have found that for dielectric substrates like glasses the special method of current control should be applied during anodizing a metal film. This method can change the porous oxide structure at the final stage and prevent formation of metal islands. To transform the residual metal into oxide, special fading process similar to anode bonding can be used.

A zeolite plate with push contacts was placed in a chamber filled with air at a controllable pressure. The current–voltage characteristics of the zeolite plate were measured as a function of the air pressure in the chamber. It is found that the gas in zeolite pores is ionized and, accordingly, the number of electrons in the pores grows. Such plate used as a cathode in a planar gas discharge cell considerably reduces the breakdown voltage of the gas discharge.

The objective of this paper is the development of light-sensitive active coatings and light-addressable microdispensors based on incorporated mesoporous particles loaded with an active agent (biocide, corrosion inhibitor). The coating includes containers either with an inorganic scaffold made of photoactive material (TiO₂) coated with polyelectrolyte shell or inert scaffold (SiO₂) coated with polyelectrolyte/nanoparticles shell where the nanoparticles are light-sensitive. The encapsulation employing two different approaches: layer-by-layer electrostatic adsorption of polyelectrolyte molecules or charged nanoparticles or pore close due to complexation between incorporated active species and polyelectrolyte which represent novel and very efficient approaches to creation of micro- and nano-sized container structures with controlled composition and permeability of the shell, complex stability for protection, delivery and storage.

A polycarbonate foil was through-irradiated with a single highly energetic lead ion. The ion crossed the foil in a straight line changing the polymer structure in the track by radiation damages such as C-C bond break. The damage track was chemically etched to a conical nanochannel with the wide aperture having a diameter in the micron range and the small aperture having a diameter in the nanometer range. On the nanochannel walls, biotin molecules were fixed. In a key-lock system, biotin acts as a biomolecular recognition element for one specific molecule, namely streptavidin. In an electrochemical set-up, the biotin-modified nanochannel acts as a sensitive and specific nanosensor with the ability to detect and quantify streptavidin in picomolar concentrations.

We are developing a nano-pipette prober that can separately detect ions, such as sodium, potassium, and calcium, in aqueous solutions. The prober can position a nano-pipette with the spacial resolution less than 100 nm by using tripod Besocke-type piezo actuators. Our recent record of the ion concentration resolution is 5 μM, and calcium ions in living cells can be distinguished with this resolution.

The fine-grained varistor ceramic (0.5-3.0 μm) was fabricated from ultradispersed ZnO and Bi₂O₃ powders (20-30 nm) which were synthesized by sol-gel technique with the use of acetylacetone and hexamethylenetetramine. Series of ceramic samples containing 1-4 mol.% of Bi₂O₃ was characterized by SEM and current-voltage characteristics.

Silicon diodes with a pn-junction, irradiated with high-energy krypton ions (250 MeV, fluences of 10⁸-10⁹ cm^-2) have been studied. The formation of an irradiation damaged layer of submicron thickness leads to nonmonotonous dependence of capacitance on reverse bias voltage.

Spin valve structures with the original transport layer of wide-band polymer have been fabricated. Essential differences in properties of ferromagnet/polymer/ferromagnet structures as compared with ferromagnet/polymer/non-magnetic metal structures have been investigated. The polymer used was poly(arylenephtalide) (PPB). The injective nature for the revealed effects has been established.

1.5 μm all-optical narrowband light modulator based on GaAs/Al_xO_y multilayer structures was demonstrated. It was shown that plane structure with a thickness less than 3 μm could effectively modulate the light at 1.5 μm, operating range being equal to 3 nm.

Micro and nanoporous carbon materials are critical for many innovative engineering applications. Such complex multi-scale porous materials have a confined fluid in the pore void: an electrolyte in the case of batteries and super-capacitors, molecular fluids (CH₄, water, CO₂) in the case of charcoal. The question that engineering scientists need to address today is how to integrate the physics of the fluid and solid behavior and their interactions into predictive engineering approaches. In this paper, I present how quantum and statistical physics concepts and methods can be used to put such porous carbon materials "under the nanoscope"; that is, allowing the assessment of the sought behavior at nanoscales aiming at bridging to engineering applications. I first illustrate this approach by showing how to get realistic samples of porous carbon replica from porous oxides (zeolites) as new forms of porous carbons with ordered texture along with disordered forms such as saccharose cokes. Then I go on with presenting how quantum chemistry methods can be used to nail down fundamentals interaction processes for H₂ adsorption. Once these relevant interactions are known, I will show their implementation in a grand canonical Monte-Carlo approach and their application in the case of H₂ storage in alkaline doped version of these porous carbons. These are also experimentally and industrially considered as electrode materials in electrochemical energy storing devices (supercapacitor and batteries). I will present the first results on electronic conductivity of these new forms of porous carbons for different polarization conditions and show the importance of texture properties on ē-conductivity. Finally, addressing the influence of simple gases adsorption on the mechanical properties of these porous matrices, I will show how CO₂ adsorption process significantly competes with the matrix elastic energy and can affectively reduce CO₂ sequestration in charcoal mines.

I review our recent results on development of hybrid materials built from semiconductor nanocry stals (NCs) and photoactive bio-complexes : membrane protein bacteriorhodopsin and photosynthetic reaction centers purified from bacteria Rhodobacter spheroides. We demonstrate that the PL emission from the NCs immobilized on the membrane surface or assembled with the reaction centers can be modulated due to the FRET-effect. This approach opens the way for application of NCs in engineering of artificial photosynthetic systems and development of hybrid light-emitting materials with advanced optical switching and photovoltaic properties.

Electrochemical performances of negative electrodes for Li-ion microbatteries composed of self-organized TiO₂ nanotubes and composites of TiO₂ nanotubes-oxide nanowires are presented.

An investigation about the absorption in organic layers incorporating metallic nanospheres is presented. The organic layers are composed of a MEH-PPV:PCBM bulk heterojunction while silver is selected as a metal. A numerical method to calculate the intrinsic absorption of each material is described. Results confirm the potential of such plasmonic structures for increasing efficiency of organic solar cells.

We report on experimental results of new generation of GaSb-based solar cell structures operating under high solar concentration. The GaSb solar cell systems, made of pin junction fabricated by molecular beam epitaxy (MBE) on GaSb substrate, were tested for the first time under solar concentration up to 2500 suns in continuous real sun. The measurements carried out showed that the GaSb-based prototype cells can withstand extreme test conditions and can be suitable for new kind of photovoltaic conversion.

Significant progress has been made in proton exchange membrane fuel cells (PEMFCs) development. However, several technical and scientific bottlenecks remain to be overcome before real market launch. One route to improve performance and durability of PEMFCs is to introduce nanomaterials in the membrane-electrode assembly (MEA).

Composite membranes where inorganic fillers are dispersed in a polymeric matrix are promising electrolytes for fuel cell applications. Homogeneity at molecular level can be achieved developing hybrids, where the inorganic component is functionalized with organic moieties. In this contribution, organic/inorganic nanohybrid membranes consisting of functionalized TiO₂ and sulfonated poly (ether ether ketone) (SPEEK) are presented. The formation of the composite substantially modifies the properties of SPEEK in terms of mechanical behavior, water uptake and solubility.

Nanostructured porous silicon impregnated by solid state oxidants has been studied in order to provide combustion and explosion processes for jet-propulsion microsystems. The pendulum systems with jet-propulsion movement on a silicon chip has been used for impulse measurements. The estimated impulse value is in the range of 1-5 mN·s.

Peculiarities of hydrogen generation with the use of micro- and nanostructured silicon powders are examined.

The photocatalytic H₂ evolution from water over CuO loaded SrTiO₃ nanoparticles has been investigated using CH₃OH as a sacrificial reagent. The results show that the CuO loaded SrTiO₃ nanoparticles are an efficient photocatalyst with a H₂ evolution rate of 5.81 mmol h^-1g^-1 under UV irradiation. Moreover, the photocatalyst is confirmed to be stable and can keep high activity for a long time.

Cr-doped ZnO nanoparticles with various Cr contents were successfully prepared by the coprecipitation-calcination method. The visible light photocatalytic activity of ZnO was enhanced when an appropriate amount of Cr was introduced in ZnO, which was attributed to the formation of the impurity levels and effective separation of photo-generated electron/hole pairs.

Three kinds of thin films were prepared: the microcrystalline In₂S₃ films of 10-800 nm thicknesses, the textured multilayer films consisting of CdS nanocrystals, the textured multilayer films of various layer thickness and composition. Their investigations performed have shown the multilayer films to be the best as low-cost photovoltaic structures.

Lignocellulose fibers were modified with polyelectrolyte/titanium dioxide layer-by-layer coating. Their adsorption and photocatalytic properties in the reaction of methylene blue dye degradation were studied.

A family of new Mg(Si,Ge,Sn)(As,Sb)₂ semiconductor compounds was theoretically estimated to be used in optoelectronics. Theirs enthalpies of formation, electronic and optical properties have been evaluated.

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