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The transport characteristics of single-atom transistors with charge centers based on Sc, Cr, Ru, Rh, and Pt atoms are studied. Single-particle electron spectra of molecules of the coordination compound of these atoms with an aurophilic terpyridine derivative in different charge states are calculated and their features are analyzed. The effect the length of linkers have on the properties of effective tunnel barriers and transport characteristics of a single-atom transistor is studied.

The method of parameterization of the electron energy spectrum of molecules is used to theoretically study the specific features of the energy spectrum of a family of molecules of the monometallic coordination compound of terpyridine with Rh, Ru, and Pt atoms and the electron transport properties of molecular single-atom transistors based on this family of molecules. The coefficients for the parametric shell model of the energy spectrum are obtained for the studied molecules. It is demonstrated that the electron-transport characteristics of molecular single-atom transistors with atoms of transition metals with similar numbers of d electrons have similar shapes and features.

A novel technique for the production of metal electrodes of a nanotransistor with a nanogap less than 4 nm between them is developed on the basis of controlling the electromigration of previously suspended nanowires of the system. A method that allows the embedding of a molecule of Rh(III) terpyridine with aurophilic ligands between electrodes is elaborated, as well. The characteristics of electron transport through a system that consists of the specified molecule with a single-atom charge center indicate the correlated (single-electron) tunneling of electrons.

We report on a fabrication method of extremely small metallic nanostructures which uses commercially available polystyrene with low molecular weight as a negative resist for electron-beam lithography. The samples were covered with polystyrene by physical vapor deposition. The method allows to form structures with a high (5–10 nm) spatial resolution and a high yield on non-uniform arbitrary shaped surfaces. The technological processes for forming line or dot arrays, electrodes with nanogaps, and radially located electrodes were developed. The process parameters are presented in this work. The possibility of fabrication of nanostructures on a cantilever tip apex of the scanning probe microscope was also demonstrated.

Colloidal membranous vesicles based on the functionalized liposomes are promising for development of novel efficient systems of controlled and stimuli-triggered drug delivery. In particular, the specific metabolism of cancer cells results in significant acidification in tumors, and thus the corresponding pH value changes can be used as a stimulus for drug release specifically in the tumor areas. pH-sensitive liposomes can be formed via incorporation of special pH-sensitive amphiphilic compounds into the liposomal membrane. Molecules of such compounds undergo a conformational transition caused by certain changes in the pH value of aqueous environment and resulting in corresponding membrane perturbations with rapid leakage of drug content from those liposomes into the areas with corresponding acidity. In the present work the pH-induced changes of Langmuir monolayer compression isotherm and of the structure of corresponding Langmuir-Blodgett films of pH-sensitive synthetic lipid trans-4,5,didodecyloxycarbonyl-trans-2-morpholinocyclohexanol have been observed and studied. The substantial expansion of Langmuir monolayer of that lipid caused by change of the aqueous subphase pH value from 7 to 5 was observed. Corresponding monolayer Langmuir-Blodgett films were deposited on mica substrate surface and studied using AFM technique. The substantial differences in the structure of Langmuir-Blodgett films deposited at pH values 7 and 5 were found. The observed effects directly demonstrate the pH-induced structural transformations in organized condensed planar molecular systems formed by pH-sensitive lipid molecules which underlie the pH-sensitivity of corresponding liposomal bilayer membranes containing such lipids.

Development and study of novel biomimetic and biocompatible functional nanofilm structures, surfaces and colloid membranous vesicles are currently important from fundamental and applied viewpoints. They can serve as model systems for insight into the basic structural-functional interconnections and physicochemical mechanisms at the nano-scale in biomembranous systems, and are useful for development of engineering solutions efficient for bio-medical applications including controlled drug delivery. We present here the results of a study of novel nanofilm composite structures (Langmuir monolayers, Langmuir-Blodgett films and liposomes) based on the interfacial complexes formed by biogenic lipid phosphatidylcholine, synthetic amphiphilic water-insoluble polyamine stearoylspermine (a derivative of biogenic polyamine spermine and stearic acid), colloid cationic ligand-free magnetite nanoparticles and polyanions (DNA, Poly(styrenesulfonate)). It was found that stearoylspermine molecules formed stable Langmuir monolayer on an aqueous subphase surface and that monolayer compression isotherm changed as a result of interactions of the stearoylspermine monolayer with aqueous subphase components (colloid cationic magnetite nanoparticles and polyanions). Monolayer Langmuir-Blodgett films of interfacial polycomplexes formed by stearoylspermine and magnetite nanoparticles or DNA molecules were deposited onto the mica substrate surface and the structure of polycomplex films was investigated using AFM. The data obtained using Langmuir monolayer technique were further used in formation of new composite nanofilm magnetic colloidal membranous vesicles based on the interfacial polycomplexes of phosphatidylcholine, stearoylspermine, magnetite nanoparticles and polyanions. The nanocomposite membranous vesicles were prepared successfully by sequential adsorption of colloid cationic ligand-free magnetite nanoparticles and polyanions onto the cationic surface of mixed phosphatidylcholine/stearoylspermine liposomes preliminarily formed using conventional ultrasound method. The formed vesicles were characterized by transmission electron microscopy, AFM, electron magnetic resonance technique, laser light scattering and electrophoresis techniques. The synthesized stable biocompatible nanocomposite magnetic liposomal vesicles can be useful in development of novel efficient systems for capsulation, targeted transport, controlled spatial localization and physical stimuli-addressed drug and DNA delivery.

We present the results of an experimental study of electron transport through individual phosphorus dopants implanted into a silicon crystal. We developed an original technique for single-electron transistor fabrication from silicon-on-insulator material with an island formed by single phosphorus atoms. The proposed method is based on well-known CMOS compatible technological processes that are standard in semiconductor electronics and may be used in most research groups. The large Coulomb blockade energy value of the investigated single-electron transistor (∼20 meV) allows one to observe single-electron effects in a wide temperature range up to 77 K. We measured and analyzed stability diagrams of fabricated experimental structures. We demonstrated a single-electron transistor with controllable electron transport through two to three phosphorus dopants only.

The single-particle electron energy spectrum and total electron energy spectra of a hydrogenically passivated central fragment of a coordination compound of rhodium with an aurophile terpyridine derivative (CCRATD) in different charge states ranging from–3e to +3e are obtained. The electron transport characteristics for a single-electron molecular transistor based on a CCRATD molecule are calculated and analyzed.

Here we present an original CMOS compatible fabrication method of a single-electron transistor structure with extremely small islands, formed by solitary phosphorus dopants in the silicon nanobridge. Its key feature is the controllable size reduction of the nanobridge in sequential cycles of low energy isotropic reactive ion etching that results in a decreased number of active charge centers (dopants) in the nanobridge from hundreds to a single one. Electron transport through the individual phosphorous dopants in the silicon lattice was studied. The final transistor structure demonstrates a Coulomb blockade voltage of ∼30 mV and nanobridge size estimated as [Formula: see text]. Analysis of current stability diagrams shows that electron transport in samples after the final etching stage had a single-electron nature and was carried through three phosphorus atoms. The fabrication method of the demonstrated structure allows it to be modified further by various impurities in additional etching and implantation cycles.

An electron transport through the extremely small gaps (1–5 nm wide) formed in narrow and thin gold nanowires by the electromigration method is studied in this work at various temperatures. A careful investigation of the final stage of a gap formation has shown a quantum character of a nanowire conductivity on this stage. Analysis of the electron transport characteristics through the resulting gaps was carried out. It shows that regimes of both a direct tunneling between electrodes and a “cold” emission into a barrier region were realized. Significant reduction of electron work function for gold electrodes of prepared gaps is revealed.

A planar topology for a nanoelectronic transducer based on glucose oxidase is designed for use in an enzymatic biosensor. Electromigration is used to create 5-nm gaps in Au nanowires. A method for the chemical modification of a silica surface with epoxysilane is developed and glucose oxidase is immobilized on the surface of a support by means of linking molecules. A technique for biochemical signal registration is developed. The eelectric response of the biosensor with glucose in a test solution and the dependence of this response on the glucose concentration are investigated.

A method for determination of the mutual effective capacitance for molecules, molecular clusters, and nanoparticles on the basis of the quantum-mechanical calculation of the interaction energy of nanoscale charged objects is proposed. The mutual effective capacitance for pairs of similar molecules (carborane C2B10H12, fullerene C60, and molecular cluster Pt5(CO)6(PPh3)4) with a size of 0.3 to 0.7 nm is calculated for distances between these molecules from 2 to 20 nm. It is demonstrated that this method makes it possible to determine the scale of distances between nanoobjects for which it is necessary to take into account quantum corrections.

We have developed a method for producing an atomically smooth (surface roughness within 0.2 nm over an area of 1000 nm2) gold surface and depositing Au nanoparticles (3–13 nm) on it via a self-assembly process.

A method to determine the effective self-capacitance of atomic and molecular objects is proposed. Experimental data and the results of quantum-mechanical computations are used to calculate the self-capacitance of atoms and various molecules. It is demonstrated that the self-capacitance is predominantly determined by the topology of the nanoobject rather than its chemical composition. The notion of the effective self-capacitance makes it possible to establish a relation of the chemical parameters of atoms and molecules and the electric parameters of molecular electronic devices.

Gaps with a size of less than 5 nm have been fabricated in 15-nm-thick and 200-nm-wide gold strips deposited on sapphire substrates. Preparation conditions providing a sufficient adhesion of such electrodes as well as the parameters for the electromigration process used to fabricate the gaps have been found which allow a successful gap implementation. Such gaps transform gold strips to the source-drain electrodes of planar single electron transistors based on nanoparticles or molecules.

Blank chips for a molecular single-electron transistor were created with the use of etching technology with a focused ion beam. Etching can be characterized as a process with a high speed of production, great reproducibility, mild requirements for prior lithographic operations, and rather good possibilities for decreasing gap width. The optimal parameters of scission of the metallic jumper of the electrodes were found, so that it is possible to create a 70 nm gap suitable for the production of a system with “overhanging” electrodes.

The surface topography of silicon and germanium single crystals formed under 10-keV Ar+ and Ne+ irradiation was studied experimentally. A relief with typical nanometer-scale dimensions is detected using atomic-force microscopy. It is established that the average height of the nanorelief formed depends on the silicon doping levels. It is also shown that the average height is determined by the parameters of ion irradiation.

Numerical calculations of equilibrium state energies and local magnetic fields in planar ring-like nanoparticle structures were performed. The dipole–dipole, Zeeman and magnetic anisotropy interactions were included into the model. The result of their competition depends on the value of the external magnetic field, magnetic parameters of an individual nanoparticle, size and shape of the structures. Flux-closed vortexes, single domain, two- domain ‘‘onion’’-like, ‘‘hedgehog’’-like and more complex spin structures can be realized. The critical field, providing a sharp transition from the flux-closed vortex to the ‘‘onion’’-like state, can be regulated by a variation of the particle magnetization and anisotropy constant, their easy directions, and particle space arrangement.

Ultimately thin monomolecular ordered stable polymeric nanocomposite films containing incorporated ligand-stabilized Au"1"0"1 nanoclusters were formed and characterized by STM and transmission electron microscopy techniques. It was demonstrated that obtained nanocomposite films can be perspective for the room temperature single-electron devices. The method proposed is perspective for design and fabrication of new controlled-morphology organized planar polymeric composite nanostructured materials, films and coatings including ultimately thin monolayer films.

A technique for the calculation of current-to-voltage curves and control curves of a molecular single-electron transistor with a discrete energy spectrum has been developed. The effective recursive methods for quick computation of the Gibbs canonical distribution of electrons between energy levels, as well as techniques for the fast calculation of the distribution function for a slow relaxation process have been found. Characteristics of the single-electron transistor in the cases of different types of molecule's energy spectrum, fast and slow energy relaxations have been compared.

In present work, we describe the formation and deposition of mixed Langmuir monolayers composed of inert amphiphile molecular matrix and guest ligand-stabilized metal-core nanoclusters. Such approach allowed obtaining the ordered stable reproducible planar monolayer and multilayer nanocluster nanostructures on solid substrates. The use of novel polymeric Langmuir monolayers formed by amphiphilic polyelectrolytes and nanoclusters resulted in fabrication of ultimately thin monomolecular nanoscale-ordered stable planar polymeric nanocomposite films. Morphology and electron transport in fabricated nanostructures were studied experimentally using AFM and STM. The perspectives for nanoelectronic applications of organized planar nanostructures from ligand-stabilized nanoclusters are discussed.

The molecular nanoclusters proved to be very promising objects for applications in electronics not only because they have absolutely identical chemical structure and allow for bottom to top approach in constructing new electronic devices, but also for the possibility to design and create great variety of such clusters with specific properties. The formation and deposition of mixed Langmuir monolayers composed of inert amphiphile molecular matrix and guest ligand-stabilized metal-core nanoclusters are described. This approach allowed to obtain the ordered stable reproducible planar monolayer and multilayer nanocluster nanostructures on solid substrates. The use of novel polymeric Langmuir monolayers formed by amphiphilic polyelectrolytes and nanoclusters resulted in fabrication of ultimately thin monomolecular nanoscale-ordered stable planar polymeric nanocomposite films. The morphology and electron transport in fabricated nanostructures were studied experimentally using AFM and STM. The effects of single electron tunneling at room temperature through molecular cluster object containing finite number of localized states were theoretically investigated taking into account electron–electron Coulomb interaction. It is shown that tunnel current-bias voltage characteristic of such tunnel junction is characterized by a number of staircase steps equal to the number of cluster's eigenlevels, however the fronts of each steps are asymptotically linear with finite inclination. The analytically obtained current–voltage characteristics are in agreement with experimental results for electron tunneling through molecular nanoclusters at room temperatures.

Clusters, nanoparticles, nanowires, long molecules as nanotubes and polynucleotides, and functional supramolecular nanostructures are currently considered as potential building blocks for nanotechnology and nanoelectronic devices and circuits, and development and introduction of new methods to control effectively their structure, composition and nanoscale organization are necessary. Here we describe a number of new nanofabrication methods which are based on the monolayer techniques, biomimetic principles, interfacial reactions and interactions. The methods allowed to produce new stable reproducible planar one-dimensional and two-dimensional arrays of ligand-stabilized nanoclusters and nanoparticles on solid substrates, ultrathin polymeric nanoscale-ordered mono- and multilayer quasi-crystalline and nanocomposite films, planar polymeric complex films with integrated DNA and inorganic building blocks as semiconductor and iron oxide nanoparticle quasi-linear arrays and nanowires. Transmission electron microscopy, STM and AFM techniques were used to characterize the fabricated nanostructures. Effects related to discrete electron tunneling were observed in the monolayers of nanoclusters and small gold nanoparticles at room temperature using STM.

The use of molecular clusters as a basis of molecular single-electronic systems is considered experimentally and theoretically. The Langmuir-Blodgett formation and scanning tunneling microscope study of structures with chemically different cluster molecules is described. I-V curves and control curves of molecular single-electron transistors based on various single molecules were studied at room temperature. Comparison of experimental I-V curves with simulated ones allows us to identify a regime of slow energy relaxation of electrons in experimental transistors. Experimental study of electron transport through the planar molecular nanosystems has shown a correlated character of electron tunneling in such systems.

New nanofabrication methods based on the monolayer techniques, biomimetic principles, interface reactions and interactions have been developed. The formation and deposition of the mixed Langmuir monolayers composed of inert amphiphile matrix and guest ligand-stabilized metal-core nanocluster molecules allowed to obtain ordered stable reproducible planar monomolecular nanocluster-based nanostructures on solid substrates. The decomposition of similar metal–organic precursor compounds in the mixed Langmuir monolayers at the gas–liquid interface resulted in the initiation of two-dimensional growth of inorganic nanoparticles in the plain of monolayer. Gold and iron-containing nanoparticles were synthesized and characterized by scanning probe microscopy and transmission electron microscopy techniques. Effect of external applied field on the shape of two-dimensionally grown magnetic nanoparticles was observed. Effects related to discrete electron tunneling were observed in the monolayer structures of nanocluster molecules and gold nanoparticles at room temperature using STM.

Electroluminescence from a single CdSe nanocrystal (NC) excited by the tunneling current of a scanning tunneling microscope (STM) is measured. Such samples produce no plasmon emissions. This allows us to measure pure signals from nanocrystals. The time dependence of electroluminescence differs from the photoluminescence of an identical nanocrystal because of different physical processes of excitation.

This work is the result of coherent effort of a multi-disciplinary research team working for a considerable number of years in the former USSR in the area of nanocluster molecular electronics. For the first time the successful demonstration of a single-electron tunnelling transistor working reliably at room temperature and based on a single molecular metallorganic cluster is presented. A broad spectrum of different molecular clusters was investigated. Our group has developed a complete cycle of custom-designed molecular cluster manufacturing, deposition, characterization and modification of nanoelectronic devices based on a single molecular cluster. It was shown that the atomic and electronic structure of nanoclusters containing from 3 up to 23 metal atoms had no crucial importance for the transistor fabrication. At the same time extensive research into characteristics of nanoelectronic devices based on single molecular clusters and their tunnelling properties is summarized.

Current–voltage curves of molecular single-electron tunneling transistors are simulated based on a modified theory of single electronics that accounts for the discreteness of the energy spectrum of the molecule. The simulation was performed including effects of energy relaxation of the electrons in the molecule for two limiting cases of fast and slow relaxation, and for both equidistant and randomly spaced energy levels of the molecule. An efficient recursion method allowing a fast calculation of the Gibbs canonical distribution for electrons in the molecule is suggested and realized. A comparison of the simulated I–V curves with the experimental ones shows that the experimental conditions correspond to the slow relaxation case.

The morphological and electron-transfer properties of cytochrome c monolayer Langmuir–Blodgett (LB) films deposited on a graphite electrode have been studied using scanning tunneling microscopy (STM) and tunneling spectroscopy techniques in a double tunnel junction configuration STM tip–cytochrome c monolayer–conducting substrate. Monolayer cytochrome c LB films were deposited successfully by horizontal lifting method via protein Langmuir monolayer formation using preliminary solubilization of the protein in water bubbles of reverse microemulsion of Aerosol OT in hexane. Electronic spectroscopy of a single cytochrome c molecule was carried out with sub-nanometer spatial resolution at the ambient conditions. The STM spectroscopic study, by recording tunneling current–bias voltage (I–V) curves, revealed nonsymmetric I–V curves with steps of variable widths and heights dependent on the STM tip position over the protein molecule. Complex-rich structure of the tunneling current–voltage spectra can be a result of the interplay between Coulomb charging effects and tunneling through discrete electronic levels of the cytochrome c molecule. It can also be determined by the tunnel junctions parameters, dependent on the state of cytochrome c molecules in the gap between the STM tip and the substrate, presence of absorbates and ‘electron paths’ effects in the protein molecule.

An approach based on the use of mixed Langmuir–Blodgett (LB) films containing various chemically synthesized nanocluster molecules has been proposed in order to create single-electron transfer model systems functioning at room temperatures. The nanoclusters are shown to form ordered structures (quasilinear chains, two-dimensional arrays, etc.) in such monolayers deposited onto the solid substrates. The tunnel current–bias voltage ( I – V ) characteristics of isolated cluster molecules Pt 5 (CO) 6 (PPh 3 ) 4 taken at 300 K exhibit rich structures resulting from the interplay between Coulomb charging effects and discreteness of an electronic spectrum of the cluster. The platinum Pt 5 (CO) 6 (PPh 3 ) 4 clusters appear to posses surface-active properties and can form stable homogeneous Langmuir monolayers on the water surface. Such monolayers can be effectively transferred onto the solid substrates so that corresponding multilayer LB films are obtained. X-ray difractograms recorded for those films show a number of Bragg peaks caused by the ordered layered structure of the films. Close values of intensity of the second harmonic generation measured for the mono- and 11-layer LB films of the platinum clusters give evidence of the centrosymmetrical Y-type packing of the cluster molecules in multilayer LB films. The pertinent theoretical model of cluster molecule packing in such films has been proposed.

Effects of applied electric and magnetic fields on the two-dimensional (2-D) growth of colloid nanoparticles have been studied. 2-D photochemical generation of amorphous iron-containing magnetic nanoparticles was carried out via ultraviolet decomposition of a volatile organometallic compound iron pentacarbonyl in a mixed Langmuir monolayer at the gas/water interface with stearic acid as a surfactant matrix. During the formation of nanoparticles the monolayer was in the 2-D gas phase state (at very low or no surface pressure). Magnetic properties of nanoparticulate multilayer Langmuir–Blodgett films were studied using electron paramagnetic resonance technique, and ferromagnetic resonance and superparamagnetic signals were observed in the material. Scanning tunneling microscopy and transmission electron microscopy analyses of deposited nanoparticulate films showed that the size and shape of synthesized nanoparticles can be changed dramatically from plate-like to aligned acicular when external magnetic field parallel to the plane of monolayer was applied during the synthesis of nanoparticles. Effects of synergistically applied electric and magnetic fields were also observed. The data obtained and model calculations give evidence that anisotropic interparticle dipole–dipole interactions and kinetic factors can play substantial role in the dipolar nanoparticle growth reactions under applied external fields. Controlling morphology of nanostructures by synthesis under applied fields could prove to be a promising approach for nanophase engineering and nanotechnology.

The morphology and electron tunneling through single cytochrome c and nanocluster Pt(5)(CO)(7)[P(C(6)H(5))](4) molecules organized as monolayer Langmuir-Blodgett (LB) films on graphite substrate have been studied experimentally using scanning tunneling microscopy (STM) and spectroscopy techniques with sub-nanometer spatial resolution in a double barrier tunnel junction configuration STM tip-monomolecular film-conducting substrate at ambient conditions. STM images of the films revealed globular structures with characteristic diameters (approximately 3.5 nm for the protein molecule and approximately 1.2 nm for the nanocluster). The spectroscopic study by recording the tunneling current-bias voltage (I-V) curves revealed tunneling I-V characteristics with features as steps of different width and heights that are dependent on the STM tip position over the molecule in the monolayer, giving evidence for sequential discrete electron-tunneling effects with the combination of the single electron Coulomb-charging energy and the electronic energy level separation (molecular spectrum) in such immobilized metalloprotein and nanocluster structures that can be of interest for the development of bioelectronic and hybrid functional nanosystems.

Molecular single-electron transistors based on small (2 - 4 nm) gold nanoparticles were fabricated using an electronbeam lithography and the electromigration method. Electrical characteristics of the obtained transistors were measured at 77 and 300 K. The characteristics show that the regime of a correlated tunneling of electrons was realized at these high for the process temperatures.

A novel approach to create ultrathin planar nanoparticulate structures based on the controllable synthesis of nanoparticles directly in Langmuir monolayer at the gas/liquid interface and subsequent deposition of monolayer is introduced. In this approach, all initial reagents are present only in monolayer and reactions of nanoparticles synthesis are initiated by decomposition of organometallic compounds under electromagnetic radiation. The changes in the shape of compression isotherm of stearic acid (SA)/iron pentacarbonyl mixed monolayer under the varying of the time of exposure to the ultraviolet light have been studied. STM images of mixed monolayers deposited onto the graphite substrate revealed synthesized iron isotropic and anisotropic magnetic nanoparticles with the characteristic size varied from 20 to 150 A in dependence on the ultraviolet exposure time and monolayer compression.

We describe the preparation and characterization of rare-earth-containing stearic acid Langmuir–Blodgett (LB) films. Stearic acid monolayer behavior on the rare-earth-containing aqueous subphase has been analyzed by thermodynamic measurements. The monolayer compression isotherm shape changed substantially by varying the anion type at the constant rare-earth cation content and pH in aqueous subphase. The conditions necessary to form highly integrated mono- and multilayered rare-earth-containing LB films were investigated. The deposited mono- and multilayer gadolinium (Gd)-containing LB films were studied by scanning tunneling microscopy (STM) and electron paramagnetic resonance (EPR) techniques. The temperature dependence of EPR signal in Gd-containing LB films indicates the magnetic ordering with a characteristic temperature of transition to complete disordered paramagnetic state of about 500 K, significantly higher than Curie temperature in bulk metal Gd. Low-field hysteresis of microwave absorption was observed in these films and pointed out to the existence of remanence magnetism in created material.

Formation of a set of planar electrodes spaced about 10 nm apart by electrochemical “healing” of gaps 50 to 100 nm wide in half-finished electrodes is described. The method consists in complete healing of the gap followed by the creation of a discontinuity at the joint of the electrodes via relaxation of stresses arising in the course of film deposition.

Complex tunnel nanostructures on the base of atomic and molecular clusters were studied by scanning tunneling microscopy. It was shown that clusters can form an ordered two-dimensional lattice in the monolayer. Electron transport through one- and two-barrier tunnel nanostructures was investigated at room temperature. The decreasing of the Coulomb blockade potential of the tunnel nanostructure with increasing of cluster nuclearity was observed.

Mixed Langmuir–Blodgett (LB) films consisting of inert molecular stearic acid matrix and embedded cluster molecules (carborane and organo-metallic molecules) were used to create reproducible, stable, ordered, planar nanostructures with different systems of electron tunnel junctions. All clusters were chemically synthesized and hence had atomically equal structure and reproducible properties. Mixed monolayers on the water surface were studied. Formed molecular structures were studied at room temperature using scanning tunneling microscopy and effects related to single-electron tunneling and energy quantization of electrons were observed in such structures.

The effect of compression of a stearic acid Langmuir monolayer on the interaction of copper ions with the monolayer and on the formation of interface clusters has been studied as functions of pH and ionic content of the water subphase. Copper binding was estimated by direct electron paramagnetic resonance measurements of ion concentrations in the water subphase. A scanning tunnelling microscopy study of monolayer Langmuir-Blodgett films, deposited on graphite substrates, gave evidence for the formation of nanosized clusters on the monolayer surface. The data obtained showed that the interaction of the monolayer with copper ions and the accompaning cluster formation processes were determined by the arrangement, order and mobility of the stearic acid molecules in the monolayer and the electrostatics at the interface.

A single-electron molecular transistor is implemented at room temperature on the basis of a stable Langmuir monomolecular film consisting of a mixture of stearic acid and carborane clusters. Control of the tunneling current with the aid of an independent voltage source is recorded at room temperature. The results are compared with the “orthodox” theory of single-charge electronics.

The characteristic features of the conductance of a tunneling contact, formed by a microscope tip and an Au/YBCO sandwich, are investigated with the aid of a scanning tunneling microscope. It is shown that there exist three types of dependences of the conductance of the structure on the applied voltage, which are distinguished by the position of the characteristic features on the voltage axis. It is established that this difference is due to the local characteristics of the proximity effect in gold films on a high-T c superconductor surface. It is concluded that the transmittance of the YBCO/Au boundary is spatially strongly nonuniform.

To create a molecular transistor, that is capable to operate in single-electron regime at room temperature, nanogap of several nanometers between electrodes is needed. Such nanogaps can be obtained by electromigration. In this work the technique of the creation of nanowire samples suitable for electromigration is described. Nanowires were formed on a substrate without buffer metallic layer to provide best conditions for electromigration process.

Integrated electrodes of molecular transistor were obtained. Electrodes includes thin-film Au strips with a 2 - 3 nm gap between them and Al gate electrode covered by Al2O3 oxide. The gap formation were made by electromigration technique and self-breaking process. Small (3 - 5 nm) gold nanoparticle were placed into the gap by self assembling. IV curves were measured at room temperature. These IV curves demonstrated single-electron conductivity of system. Such integrated system of electrodes is suitable to be the source-drain electrodes of planar single-electron transistors based on nano-particles or molecules.

Electrodes for molecular transistor with the gaps between them within 5 nm width’s range were created. On the first step suspended electrodes-blanks with 30 nm gaps was fabricated with a standard bilayer mask technology and electron beam lithography. Then wet etching in a 6% solution of hydrofluoricacid buffered with hydrofluoride of ammonium makes possible to suspend these electrodes to prevent them from short-circuit at the step of additional evaporation of metal film. The efficiency of narrowing of the gap between source and drain electrodes (as a result of additional deposition of metal film on the preformed and suspended gap) was 50-70% of the deposited film thickness.

We suggest an approach for determining nanoobjects’ energy spectra depending on its total electric charge. The approach was tested studying golden nanoparticles of different sizes surrounded by ligands of dodecanethiols. Quantum methods of Hartree-Fock and DFT were used to calculate energy spectra and capacitances for such gold nanoparticles consisting of up to 33 atoms of gold. Presence of “extra” levels in energy gap of nanobject’s spectra was revealed. Also dodecanethiol SCH2(CH2)10CH3 ligands influence on the total capacitance and energy spectrum of molecular nanocluster was shown. Finally transport characteristics for gold nanocluster based molecular single-electron transistor (MSET) were calculated using the obtained energy spectra.The simple energy spectra structure model used in the present work may allow single-electron transistor (SET) simulation for larger molecular systems.

The investigation of the effects of correlated tunneling in the molecular nanostructures at room temperatures has been carried out. The model of molecular single-electron transistor on the basis of planar techniques has been developed.

In this paper we have investigated the possibility of determining single-electron spectrum of the nano-object, that is used as the central island of a single-electron transistor. The method for the charge spectra and singleparticle transport spectra determination on the basis of the experimental stability diagram was suggested. It was shown, that to calculate the total energy spectrum of a molecular nano-object for various charging and excitation states and a single-particle spectrum, one needs to measure the blockade diamonds of the stability diagram. To identify the electron energy relaxation type in the molecular nano-object it is necessary to measure the stability diagram of the molecular single-electron transistor up to the first non-blockade diamond. In addition, a method of calculation of tunneling rates via single-particle energy levels of the molecular object has been suggested. Calculation of energy spectrum for various charging and excitation states has been carried out, on the basis of experimental data.

Blank-chips for molecular transistor were created using milling technology with focused ion beam. Optimal parameters for milling of metal electrodes were found, so it is possible to create a 30 nm gaps suitable for production of system with suspended electrodes. Electrical measurements of a gap show reliable cutting of a metal film. In situ production of simple nanostructures of various shapes potentially useful for quantum devices was demonstrated.