- CNR-SPIN, UoS Napoli
c/o Universita' di Napoli "Federico II" - Dipartimento di Fisica
Compl. Univ. M.S. Angelo, Via Cintia
I-80126 NAPOLI - Italy - +39081676910
Giovanni Cantele
Consiglio Nazionale delle Ricerche (CNR), CNR-SPIN, Faculty Member
- Computer Science, Oxide interfaces, Nwchem, Quantum-ESPRESSO, Ab initio calculations, Density-functional theory, and 23 moreGraphene, Physics, Nanomaterials, Carbon Nanotubes, Nanoparticles, Nanorod, Quantum Dots, Nanoscience, Nanotechnology, Density functional theory calculations, Titanium dioxide, Carbon Nanotube, Carbon Based Nanostructures, Solid State Physics, Condensed Matter Physics, Theoretical Condensed Matter Physics, Oxides, Surfaces and Interfaces, Nanostructured materials, DFT Calculations, Nanoscience and nanotechnology, Polymer Chemistry, and Polymer Nanocompositesedit
- My work concerns the theoretical investigation of the electronic, structural and optical properties of materials at t... moreMy work concerns the theoretical investigation of the electronic, structural and optical properties of materials at the nanoscale: nanostructured materials, surfaces and interfaces.edit
Polar surfaces are known to be unstable due to the divergence of the surface electrostatic energy. Here we report on the experimental determination, by grazing incidence x-ray diffraction, of the surface structure of polar Ti-terminated... more
Polar surfaces are known to be unstable due to the divergence of the surface electrostatic energy. Here we report on the experimental determination, by grazing incidence x-ray diffraction, of the surface structure of polar Ti-terminated (111) SrTiO 3 single crystals. We find that the polar instability of the 1 × 1 surface is solved by a pure electronic reconstruction mechanism, which induces out-of-plane ionic displacements typical of the polar response of SrTiO 3 layers to an electron confining potential. On the other hand, the surface instability can be also eliminated by a structural reconstruction driven by a change in the surface stoichiometry, which induces a variety of 3 × 3 (111) SrTiO 3 surfaces consisting in an incomplete Ti (surface)-O 2 (subsurface) layer covering the 1 × 1 Ti-terminated (111) SrTiO 3 truncated crystal. In both cases, the TiO 6 octahedra are characterized by trigonal distortions affecting the structural and the electronic symmetry of several unit cells from the surface. These findings show that the stabilization of the polar (111) SrTiO 3 surface can lead to the formation of quasi-two-dimensional electron systems characterized by radically different ground states which depend on the surface reconstructions.
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We combine state-of-the-art large-scale first-principles calculations with a low-energy continuum model to describe the nearly flat bands of twisted bilayer graphene at the first magic angle θ = 1.08º. We show that the energy width of the... more
We combine state-of-the-art large-scale first-principles calculations with a low-energy continuum model to describe the nearly flat bands of twisted bilayer graphene at the first magic angle θ = 1.08º. We show that the energy width of the flat-band manifold, as well as the energy gap separating it from the valence and conduction bands, can be obtained only if the out-of-plane relaxations are fully taken into account. The results agree both qualitatively and quantitatively with recent experimental outcomes.
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In this paper we present first-principles calculations, based on both density functional theory and maximally localized Wannier functions, to study the electronic properties and interlayer coupling of twisted MoS 2 /NbSe 2 heterobilayers.... more
In this paper we present first-principles calculations, based on both density functional theory and maximally localized Wannier functions, to study the electronic properties and interlayer coupling of twisted MoS 2 /NbSe 2 heterobilayers. We accurately investigate different stacking configurations and commensurate twist angles by including an in-depth analysis of the interlayer van der Waals interaction. The metallic character of the investigated heterostructures is dominated, at the Fermi energy, by the NbSe 2 atomic orbitals and shows a strong dependence on the twist angle. Notably, at the smallest considered twist angle, band structure flattening at the Fermi energy shows up, which should result in a lower conductivity of the metallic heterobilayer. The electrostatic potential analysis reveals no significant modification of the potential pattern with respect to the potentials of the isolated layers, with the exception of the interface region. A moderate electronic charge redistribution, compatible with electronically weakly coupled layers, is set up following the formation of the interface. The dependence of the electronic structure on the twist angle acts as a new degree of freedom for tuning properties relevant in electronic device applications.
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Few layer bismuth nanofilms with (111) orientation have shown striking electronic properties, especially as building blocks of novel two-dimensional heterostructures. In this paper we present state-of-the-art first principles... more
Few layer bismuth nanofilms with (111) orientation have shown striking electronic properties, especially as building blocks of novel two-dimensional heterostructures. In this paper we present state-of-the-art first principles calculations, based on both density functional theory and maximally localized Wannier functions, that encompass electronic and structural properties of free-standing Bi(111) nanofilms. We accurately evaluate both the in-plane lattice constant and, by including the van der Waals interaction between bismuth bilayers, the intra/interlayer distances. Interestingly and somehow unexpectedly, the in-plane lattice constant is predicted to shrink by about 5% going from the thickest investigated nanofilm (∼80Å) to single bilayer Bi(111), entailing a thickness dependent lattice mismatch in complex heterostructures involving ultrathin Bi(111). Moreover, quantum confinement effects, that would be expected to rule the electronic structure at this size range, compete with surface states that appear close to and across the Fermi level. The implication is that not only all but the thinnest films have a metallic band structure but also that such surface states might play a role in either the formation of interfaces with other materials or for sensing applications. Finally, the calculated electronic structure compares extremely well with ARPES measurements.
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First principles calculations were performed to study the interface electronic structure and the Schottky barrier heights (SBHs) of ZnO–metal interfaces. Different kinds of metals were considered with different chemistries on the polar... more
First principles calculations were performed to study the interface electronic structure and the Schottky barrier heights (SBHs) of ZnO–metal interfaces. Different kinds of metals were considered with different chemistries on the polar (0 0 0 1) and (0 0 0 $\bar1$ ) ZnO surfaces. The projection of the density of states on the atomic orbitals of the interface atoms reveals that two kinds of interface electronic states appear: states due to the chemical bonding which appear at well defined energies and conventional metal-induced gap states associated with a smooth density of states in the bulk ZnO band gap region. The relative weight and distribution of the two classes of states depend on both the ZnO substrate termination and on the metal species. SBHs are found to be very sensitive to the specific interface chemical bonding. In particular, it is possible to note the occurrence of either Schottky barriers or Ohmic contacts. Our results have been compared with experiments and with available phenomenological theories, which estimate the SBH from few characteristic material parameters. Finally, the electronic and structural contributions to the SBH have been singled out and related to the different charge transfers occurring at the different interfaces.
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We report on first principles calculations of the properties of the epitaxialSrTiO3−TiO2 (anatase) heterojunction, with an emphasis on the electronic band profile and lineup at the interface. The valence and conduction band offsets are... more
We report on first principles calculations of the properties of the epitaxialSrTiO3−TiO2 (anatase) heterojunction, with an emphasis on the electronic band profile and lineup at the interface. The valence and conduction band offsets are calculated as a function of the number of anatase layers deposited onto the SrTiO3, as well as of the position of an oxygen vacancy with respect to the interface. It is shown that the presence of oxygen vacancies in the SrTiO3 is a way to effectively lower the barrier heights at the interface. Our results are in agreement with recent experiments reporting nearly zero band offset.
We investigate the effects of constraining the motion of atoms in finite slabs used to simulate the rutile (110) surface in first-principles calculations. We show that an appropriate choice of fixing atoms in a slab eliminates spurious... more
We investigate the effects of constraining the motion of atoms in finite slabs used to simulate the rutile (110) surface in first-principles calculations. We show that an appropriate choice of fixing atoms in a slab eliminates spurious effects due to the finite size of the slabs, leading to a considerable improvement in the simulation of the (110) surface. The method thus allows for a systematic improvement in convergence in calculating both geometrical and electronic properties.
The many and diverse approaches to materials science problems have greatly enhanced our ability in recent times to engineer the physical properties of semiconductors. Silicon, of all semiconductors, underpins nearly all microelectronics... more
The many and diverse approaches to materials science problems have greatly enhanced our ability in recent times to engineer the physical properties of semiconductors. Silicon, of all semiconductors, underpins nearly all microelectronics today and will continue to do so for some time to come. However, in optoelectronics, the severe disadvantage of an indirect band gap has limited the application of elemental silicon. Here we review a number of diverse approaches to engineering efficient light emission in silicon nanostructures.
Silicon nanocrystallites (NCs) and similar nanostructures have been intensively investigated in the last years due to their interesting quantum confinement properties. 1–3 The strong spatial localization of electrons and holes in Si NCs... more
Silicon nanocrystallites (NCs) and similar nanostructures have been intensively investigated in the last years due to their interesting quantum confinement properties. 1–3 The strong spatial localization of electrons and holes in Si NCs can enhance radiative recombination rates and give rise to luminescence. Among other known applications, research on Si NCs could lead to optoelectronic devices compatible with the consolidated Si technology. Optical gain in Si NCs has been reported, 4, 5 and new devices have recently been suggested. 6, 7
We address the structural and electronic properties of graphene nanoribbons (GNRs) covalently immobilized on a metallic substrate by means of an organic layer. The GNR-organic layer and organic layer-metal interfaces can be thought of as... more
We address the structural and electronic properties of graphene nanoribbons (GNRs) covalently immobilized on a metallic substrate by means of an organic layer. The GNR-organic layer and organic layer-metal interfaces can be thought of as constituents of a nanodevice and as such have been accurately studied using large-scale density functional theory calculations.
Abstract.–In this letter, we report progress on the field theory of polymerized tethered membranes. For the toy model of a manifold repelled by a single point, we are able to sum the perturbation expansion in the strength g0 of the... more
Abstract.–In this letter, we report progress on the field theory of polymerized tethered membranes. For the toy model of a manifold repelled by a single point, we are able to sum the perturbation expansion in the strength g0 of the interaction exactly in the limit of internal dimension D→ 2. This exact solution is the starting point for an expansion in 2− D, which aims at connecting to the well-studied case of polymers (D= 1). We here give results to order (2− D) 2, where again all orders in g0 are resummed.
2 ment) demonstrate enunciated characteristic of fotoconductivity of such material if illuminated from radiation, in particular from UV. Moreover the material can be easily managed to cover wide sensitive areas and finely structured... more
2 ment) demonstrate enunciated characteristic of fotoconductivity of such material if illuminated from radiation, in particular from UV. Moreover the material can be easily managed to cover wide sensitive areas and finely structured through nanolitography. Therefore the way is open to a great number of applications in which UV, visible and near IR (150-1100 nm) radiation detectors cover particular importance.
Summary: We report on our ab-initio calculation of the adsorption of 1-amino-3-cyclopenthene on the surface of silicon nanocrystals. The bonding mechanism, the reaction path and the electronic structure are discussed in connection with... more
Summary: We report on our ab-initio calculation of the adsorption of 1-amino-3-cyclopenthene on the surface of silicon nanocrystals. The bonding mechanism, the reaction path and the electronic structure are discussed in connection with the possible use of nanostructured silicon as a biosensing material. Keywords: silicon, nanocrystal, biosensor
A theoretical model has been developed to link the nanostructure geometry of porous silicon to its optical properties. Light emission and absorption energies have been calculated within a variational scheme, which includes a... more
A theoretical model has been developed to link the nanostructure geometry of porous silicon to its optical properties. Light emission and absorption energies have been calculated within a variational scheme, which includes a position-dependent boundary condition that reflects the surface chemistry. We show that the results of our measurements of both the photoluminescence (PL) quenching and peak position shift in the presence of oxygen can be accounted for by the theory.
Interfacing semiconductor surfaces with organic molecule adsorbates is one of the most challenging aspects of the modern surface and interface engineering. Controlled and periodic surface coverage can have important implications in lots... more
Interfacing semiconductor surfaces with organic molecule adsorbates is one of the most challenging aspects of the modern surface and interface engineering. Controlled and periodic surface coverage can have important implications in lots of technological applications, such as molecular sensing, molecular electronics, etc. One of the widely investigated surfaces is the silicon $< $100 $> $. Such a surface shows a periodic arrangement of silicon dimers (induced by reconstruction) whose bonding has been ...
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Research Interests: Nanostructure and MRS
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ABSTRACT In this paper we discuss the role of local fields in the optical properties of silicon nanocrystals. Using a semiempirical tight binding approach, local field effects are included into the linear response theory, going beyond the... more
ABSTRACT In this paper we discuss the role of local fields in the optical properties of silicon nanocrystals. Using a semiempirical tight binding approach, local field effects are included into the linear response theory, going beyond the standard independent particle approximation. The results show that local field effects give an important contribution to the optical properties of silicon nanocrystals, leading to a strong suppression of the absorption in the visible spectral range. This effect is attributed to the classical surface polarization ...
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Research Interests: Engineering, Materials Engineering, Mechanical Engineering, Chemical Engineering, Inorganic Chemistry, and 27 moreOrganic Chemistry, Technology, Materials Chemistry, Physical Organic Chemistry, Multidisciplinary, Band Structure, Ultraviolet, Thin Film, Hydrogen Energy, Physical sciences, Band Gap, Luminescence, Structure Analysis, Electronic properties, Temperature Dependence, CHEMICAL SCIENCES, Optical physics, Lattice Parameter, Photoemission, THEORETICAL AND COMPUTATIONAL CHEMISTRY, Martensitic Transformation, Specific Heat, Thermal Expansion, Ab Initio Calculation, Electronic Structure Calculation, Magnetic Shape Memory, and Molecular Structure
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Abstract In this paper we report on a comparative ab initio study of the adsorption of ethylene, cyclopentene and 1-amino-3-cyclopentene on the silicon〈 100〉 surface. Accurate calculations of the reaction path have been carried out using... more
Abstract In this paper we report on a comparative ab initio study of the adsorption of ethylene, cyclopentene and 1-amino-3-cyclopentene on the silicon〈 100〉 surface. Accurate calculations of the reaction path have been carried out using a cluster model for the surface dimer (Si9H12) and Gaussian-type basis functions. The dependence of the computed reaction path on the theoretical method is investigated; activation energies turn out to be quite independent of the method, and general trends can be found for the three systems ...
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The adsorption of 1-amino-3-cyclopentene on the (100) silicon surface has been studied by methods rooted in the density-functional theory using both delocalized (plane waves, PWs) and localized (Gaussian-type orbitals, GTOs) basis... more
The adsorption of 1-amino-3-cyclopentene on the (100) silicon surface has been studied by methods rooted in the density-functional theory using both delocalized (plane waves, PWs) and localized (Gaussian-type orbitals, GTOs) basis functions. The results obtained by modeling the surface by silicon clusters of different sizes are quite similar, thus confirming that the reaction is quite localized. Furthermore, PW and GTO computations give comparable results, provided that the same density functional and carefully chosen computational parameters (contraction of GTO, pseudopotentials, etc.) are used. Slab computations performed in the PW framework show that the cluster results are retrieved when low-coverage adsorption on the surface is considered. On these grounds, we are quite confident that reaction parameters obtained by the more reliable hybrid density functional (PBE0) are essentially converged, our best estimates of reaction and activation free energies are thus -40 and 6 kcal/mol, respectively.
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There are experimental evidences that doping control at the nanoscale can significantly modify the optical properties with respect to the pure systems. This is the case of silicon nanocrystals (Si-nc), for which it has been shown that the... more
There are experimental evidences that doping control at the nanoscale can significantly modify the optical properties with respect to the pure systems. This is the case of silicon nanocrystals (Si-nc), for which it has been shown that the photoluminescence (PL) peak can be tuned also below the bulk Si band gap by properly controlling the impurities, for example by boron (B) and phosphorus (P) codoping. In this work, we report on an ab initio study of impurity states in Si-nc. We consider B and P substitutional impurities for Si-nc with a diameter up to 2.2 nm. Formation energies (FEs), electronic, optical and structural properties have been determined as a function of the cluster dimension. For both B-doped and P-doped Si-nc the FE increases on decreasing the dimension, showing that the substitutional doping gets progressively more difficult for the smaller nanocrystals. Moreover, subsurface impurity positions result to be the most stable ones. The codoping reduces the FE strongly favoring this process with respect to the simple n-doping or p-doping. Such an effect can be attributed to charge compensation between the donor and the acceptor atoms. Moreover, smaller structural deformations, with respect to n-doped and p-doped cases, localized only around the impurity sites are observed. The band gap and the optical threshold are largely reduced with respect to the undoped Si-nc showing the possibility of an impurity-based engineering of the Si-nc PL properties.
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One of the most attractive aspects of quantum confined systems has been the possibility of obtaining light emission from silicon. Significant advances made since the discovery of porous silicon opened the way toward the use of this... more
One of the most attractive aspects of quantum confined systems has been the possibility of obtaining light emission from silicon. Significant advances made since the discovery of porous silicon opened the way toward the use of this material for optoelectronic devices. 1, 2 Among the many, intriguing physical properties are those related to charge transport and sensing properties of poroussilicon-based devices. For example, it has been demonstrated that a large enhancement of the conductivity can be reached via an acceptorlike doping ...
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Nowadays we live in the so-called “Silicon Era”, in which devices based on the silicon technology permeate all aspects of our daily life. One can simply think how much silicon is in the everyday household objects, gadgets and... more
Nowadays we live in the so-called “Silicon Era”, in which devices based on the silicon technology permeate all aspects of our daily life. One can simply think how much silicon is in the everyday household objects, gadgets and appliances.The impact of silicon technology has been very relevant in photodetection as well. It enables designing large or very large-scale integration devices, in particular microchips and pixelled detectors like the Silicon Photo Multiplier made of micrometric channels grouped in mm2 pixels. However, on the horizon, the recent development of nanotechnologies is opening a new direction in the design of sub-micron photodevices, owing to the capability to deal with individual molecules of compounds or to chemically grow various kinds of materials.Among them, carbon compounds appear to be the most promising materials being chemically very similar to silicon, abundant and easy to handle. In particular, carbon nanotubes (CNT) are a very intriguing new form of material, whose properties are being studied worldwide providing important results.The photoelectric effects observed on carbon nanotubes indicate the possibility to build photodetectors based on CNTs inducing many people to claim that we are at the beginning of a Post Silicon Era or of the Carbon Era.In this paper, we report on the most important achievements obtained on the application of nanotechnologies to photodetection and medical imaging, as well as to the development of radiation detectors for astro-particle physics experiments.
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The electronic and optical properties of silicon nanocrystals passivated with hydrogen and oxygen have been investigated both in the ground- and in an excited-state configuration, through different ab-initio techniques. The presence of an... more
The electronic and optical properties of silicon nanocrystals passivated with hydrogen and oxygen have been investigated both in the ground- and in an excited-state configuration, through different ab-initio techniques. The presence of an electron–hole pair leads to a strong interplay between the structural and optical properties of the system. The structural distortion of the nanocrystals induced by an electronic excitation is analysed together with the role of the symmetry constraint during the relaxation. The structural distortion can account for the experimentally observed Stokes Shift. Size-related aspects are also analysed and discussed.
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We show that the optical and electronic properties of nanocrystalline silicon can be efficiently tuned using impurity doping. In particular, we give evidence, by means of ab-initio calculations, that by properly controlling the doping... more
We show that the optical and electronic properties of nanocrystalline silicon can be efficiently tuned using impurity doping. In particular, we give evidence, by means of ab-initio calculations, that by properly controlling the doping with either one or two atomic species, a significant modification of both the absorption and the emission of light can be achieved. We have considered impurities, either boron or phosphorous (doping) or both (codoping), located at different substitutional sites of silicon nanocrystals with size ranging from 1.1 nm to 1.8 nm in diameter. We have found that the codoped nanocrystals have the lowest impurity formation energies when the two impurities occupy nearest neighbor sites near the surface. In addition, such systems present band-edge states localized on the impurities giving rise to a red-shift of the absorption thresholds with respect to that of undoped nanocrystals. Our detailed theoretical analysis shows that the creation of an electron-hole pair due to light absorption determines a geometry distortion that in turn results in a Stokes shift between adsorption and emission spectra. In order to give a deeper insight in this effect, in one case we have calculated the absorption and emission spectra going beyond the single-particle approach showing the important role played by many-body effects. The entire set of results we have collected in this work give a strong indication that with the doping it is possible to tune the optical properties of silicon nanocrystals.
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Research Interests: Physics, Materials Science, Solid State Physics, Chemistry, Physical Chemistry, and 21 moreSurfaces and Interfaces, Soft Matter, Self Assembly, Nanoparticles, Nanotechnology, DNA, Molecular Electronics, Microemulsion, Nanoscience, Solid State electronic devices, Physical sciences, Colloids, Electron Affinity, Microemulsions, CHEMICAL SCIENCES, Surface Properties, Surface Charge, Gel, Work Function, Functional Group, and Ab Initio Calculation
Research Interests: Materials Science, Titanium, Surface Chemistry, Quantum Dots, Quantum Confinement, and 12 moreNanocrystalline Material, Solid State electronic devices, Physical sciences, Band Gap, Electronic properties, CHEMICAL SCIENCES, Surface Properties, Quantum Dot, Structural Properties, Local Density Approximation, Nanocrystals, and Experimental Data
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A first-principles calculation of the impurity screening in Si and Ge nanocrystals is presented. We show that isocoric screening gives results in agreement with both the linear response and the point-charge approximations. Based on the... more
A first-principles calculation of the impurity screening in Si and Ge nanocrystals is presented. We show that isocoric screening gives results in agreement with both the linear response and the point-charge approximations. Based on the present ab initio results, and by comparison with previous calculations, we propose a physical real-space interpretation of the several contributions to the screening. Combining the Thomas-Fermi theory and simple electrostatics, we show that it is possible to construct a model screening function that has the merit of being of simple physical interpretation. The main point upon which the model is based is that, up to distances of the order of a bond length from the perturbation, the charge response does not depend on the nanocrystal size. We show in a very clear way that the link between the screening at the nanoscale and in the bulk is given by the surface polarization. A detailed discussion is devoted to the importance of local field effects in the screening. Our first-principles calculations and the Thomas-Fermi theory clearly show that in Si and Ge nanocrystals, local field effects are dominated by surface polarization, which causes a reduction of the screening in going from the bulk down to the nanoscale. Finally, the model screening function is compared with recent state-of-the-art ab initio calculations and tested with impurity activation energies.
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By combining ab initio all-electron localized orbital and pseudopotential plane-wave approaches we report on calculations of the electron affinity (EA) and the ionization potential (IP) of (5, 5) and (7, 0) single-wall carbon nanotubes.... more
By combining ab initio all-electron localized orbital and pseudopotential plane-wave approaches we report on calculations of the electron affinity (EA) and the ionization potential (IP) of (5, 5) and (7, 0) single-wall carbon nanotubes. The role played by finite-size effects and nanotube termination has been analysed by comparing several hydrogen-passivated and not passivated nanotube segments. The dependence of the EA and IP on both the quantum confinement effect, due to the nanotube finite length, and the charge accumulation on the edges, is studied in detail. Also, the EA and IP are compared to the energies of the lowest unoccupied and highest occupied states, respectively, upon increasing the nanotube length. We report a slow convergence with respect to the number of atoms. The effect of nanotube packing in arrays on the electronic properties is eventually elucidated as a function of the intertube distance.
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Research Interests: X ray absorption spectroscopy, Band Structure, Silica, Computational Condensed Matter Physics, Solid State electronic devices, and 16 morePhysical sciences, Long Range, Band Gap, Nitrogen, Optical Properties, Electronic properties, Electron Density, Electronic Structure, CHEMICAL SCIENCES, Spectrum, Excited states, Microstructures, Structural Properties, Porous Material, Experimental Data, and Structural model
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We characterize the transport properties of functionalized graphene nanoribbons using extensive first-principles calculations based on density functional theory (DFT) that encompass both monovalent and divalent ligands, hydrogenated... more
We characterize the transport properties of functionalized graphene nanoribbons using extensive first-principles calculations based on density functional theory (DFT) that encompass both monovalent and divalent ligands, hydrogenated defects and vacancies. We find that the edge metallic states are preserved under a variety of chemical environments, while bulk conducting channels can be easily destroyed by either hydrogenation or ion or electron beams, resulting in devices that can exhibit spin conductance polarization close to unity.
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Oxygen vacancies at the SnO2(110) and (101) surface and subsurface sites have been studied in the framework of density functional theory by using both all-electron Gaussian and pseudopotential plane-wave methods. The all-electron... more
Oxygen vacancies at the SnO2(110) and (101) surface and subsurface sites have been studied in the framework of density functional theory by using both all-electron Gaussian and pseudopotential plane-wave methods. The all-electron calculations have been performed using the B3LYP exchange-correlation functional with accurate estimations of energy gaps and density of states. We show that bulk oxygen vacancies are responsible for the appearance of a fully occupied flat energy level lying at about 1 eV above the top valence band, and an empty level resonant with the conduction band. Surface oxygen vacancies strongly modify the surface band structures with the appearance of intragap states covering most of the forbidden energy window, or only a small part of it, depending on the vacancy depth from the surface. Oxygen vacancies can account for electron affinity variations with respect to the stoichiometric surfaces as well. A significant support to the present results is found by comparing them to the available experimental data.
Research Interests: Materials Science, Soft Matter, Self Assembly, Nanoparticles, Density-functional theory, and 17 moreDNA, Band Structure, Microemulsion, Density Functional Theory, Physical sciences, Colloids, Electron Density, Electron Affinity, Microemulsions, CHEMICAL SCIENCES, Metal Oxide, Oxygen Vacancies, Gel, Tin Dioxide, Experimental Data, Energy Levels, and Correlation function
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"This textbook provides conceptual, procedural, and factual knowledge on solid state and nanostructure physics. It is designed to acquaint readers with key concepts and their connections, to stimulate intuition and curiosity, and to... more
"This textbook provides conceptual, procedural, and factual knowledge on solid state and nanostructure physics. It is designed to acquaint readers with key concepts and their connections, to stimulate intuition and curiosity, and to enable the acquisition of competences in general strategies and specific procedures for problem solving and their use in specific applications. To these ends, a multidisciplinary approach is adopted, integrating physics, chemistry, and engineering and reflecting how these disciplines are converging towards common tools and languages in the field.
Each chapter discusses essential ideas before the introduction of formalisms and the stepwise addition of complications. Questions on everyday manifestations of the concepts are included, with reasoned linking of ideas from different chapters and sections and further detail in the appendices. The final section of each chapter describes experimental methods and strategies that can be used to probe the phenomena under discussion.
Solid state and nanostructure physics is constantly growing as a field of study where the fascinating quantum world emerges and otherwise imaginary things can become real, engineered with increasing creativity and control: from tinier and faster technologies realizing quantum information concepts, to understanding of the fundamental laws of the Universe, unifying the tiniest lengths below those of nuclear constituents with the giant cosmic distances. Elements of Solid State Physics and of Crystalline Nanostructures will offer the reader an enjoyable insight into the complex concepts of solid state physics."
Each chapter discusses essential ideas before the introduction of formalisms and the stepwise addition of complications. Questions on everyday manifestations of the concepts are included, with reasoned linking of ideas from different chapters and sections and further detail in the appendices. The final section of each chapter describes experimental methods and strategies that can be used to probe the phenomena under discussion.
Solid state and nanostructure physics is constantly growing as a field of study where the fascinating quantum world emerges and otherwise imaginary things can become real, engineered with increasing creativity and control: from tinier and faster technologies realizing quantum information concepts, to understanding of the fundamental laws of the Universe, unifying the tiniest lengths below those of nuclear constituents with the giant cosmic distances. Elements of Solid State Physics and of Crystalline Nanostructures will offer the reader an enjoyable insight into the complex concepts of solid state physics."
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The crucial role of atomic corrugation on the flat bands and energy gaps of twisted bilayer graphene at the "magic angle" θ∼1.08∘