Anton Grigoriev

• Ph.D.
• Uppsala University

Molecular electronic devices based on few and single-molecules have the advantage that the electronic signature of the device is directly dependent on the electronic structure of the molecules as well as of the electrode-molecule junction. In this work, we use a two-step approach to synthesise functionalized nanomolecular electronic devices (nanoMo...

Graphene has stimulated great enthusiasm in a variety of fields, while its chemically inert surface still remains challenging for functionalization towards various applications. Herein, we report an approach to fabricate non-covalently functionalized graphene by employing π-π stacking interactions, which has potentialities for enhanced ammonia dete...

We explore the possibility of using van dar Waals bonded heterostructures of stacked together 2D bilayer black phosphorus (BP) for nanoscale device applications. The electronic property of BP in AA stacking and 90àtwisted is studied with density functional theory. Further, we study the homogeneous nanojunction architecture of BP to use its anisotro...

We find from our calculations that the binding energies for the NO 2 molecules, calculated in this paper, are too low, most likely due to the lacking optimization of the site at which the gas molecule binds to the BPDT.

Overcoming the global energy crisis due to vast economic expansion with the advent of human reliance on energy-consuming labor-saving devices necessitates the demand for next-generation technologies in the form of cleaner energy storage devices. The technology accelerates with the pace of developing energy storage devices to meet the requirements w...

The current-time (i-t) data acquired from molecular electronics devices can show different noise components and in some devices the noise resembles random telegraph signal (RTS). Here we report the modulation of multilevel RTS under the effect of external environment which is observed in highly sensitive current measurements, performed on gold nano...

Recent significant advancements have been made in demonstrating the usage of phosphorene to detect the presence of gases leading to a new breed of gas sensor device. Based on pristine phosphorene, the devices can detect a small concentration of adsorbed molecules with high sensitivity at room temperature. In this work, we propose doping silicon and...

The interaction of a gas molecule with a sensing material causes the highest change in the electronic structure of the latter, when this material would consist of only a few atoms only. If the sensing material consists of a short, conductive molecule, the sensing action can be furthermore probed by connecting such molecules to nanoelectrodes. Here,...

The interaction of a gas molecule with a sensing material causes the highest change in the electronic structure of the latter, when this material consists of only a few atoms. If the sensing material consists of a short, conductive molecule, the sensing action can be furthermore probed by connecting such molecules to nanoelectrodes. Here, we report...

Blue fluorescent hexagonal boron nitride quantum dots (h-BNQDs) of ∼10 nm size as an effective enhancer for DNA cleavage activity of anticancer drug doxorubicin (DOX) were synthesized using simple one-step hydrothermal disintegration of exfoliated hexagonal boron nitride at very low temperature ∼ 120 °C. Boron nitride quantum dots (BNQDs) at a conc...

We explore the possibility of using van dar Waals bonded heterostructures of stacked together 2D bilayer black phosphorus (BP) for nanoscale device applications. The electronic property of BP in AA stacking and 90{\deg} twisted is studied with density functional theory. Further, we study the homogeneous nanojunction architecture of BP to use its an...

Two recent reports on realization of elemental 2D analogue of graphene: borophene (Science, 350, 1513-1516 (2015); Nature Chemistry, 8, 563–568 (2016)) focus on the inherent anisotropy and directional dependent electronic properties in borophene polymorphs. Accomplishing stable 2D borophene structures may lead to some degree of strain in the system...

Experimental realization of two-dimensional boron sheets was reported very recently by Feng et. al. using molecular beam epitaxy on silver (111) surface. These boron sheets possess promising electronic and transport properties. We performed the density functional theory (DFT) calculation to see the stability of two $\beta_{12}$ and $\chi$ polymorph...

To the league of ever expanding 2D materials, borophene is a recent addition. Herein, a combination of ab initio density functional theory (DFT) and non-equilibrium Green’s function (NEGF) based methods is used to estimate this prospects of this promising elemental 2D material for gas sensing applications. We note that the binding of target gas mol...

Recent advances in solid state nano device based DNA sequencing are at the helm of the development of a new paradigm, commonly referred to as personalized medicines. Paying heed to a timely need for standardizing robust nano devices for cheap, fast and scalable DNA detection, in this article, nanogap formed by lateral heterostructure of graphene an...

A great deal of interest has been paid to the application of carbon-based nano- and microstructured materials as electrodes due to their relatively low-cost production, abundance, large surface area, high chemical stability, wide operating temperature range, and ease of processing including many more excellent features. The nanostructured carbon ma...

Dilithium benzenedipropiolate was prepared and investigated as a potential negative electrode material for secondary lithium-ion batteries. In addition to the expected reduction of its carbonyls, this material can reduce and reversibly oxidize its unsaturated carbon−carbon bonds leading to a Li/C ratio of 1/1 and a specific capacity as high as 1363...

The fundamental electronic structure properties of substituted poly(penta)fulvenes and pentafulvene-based polymers are analyzed through qualitative molecular orbital (MO) theory combined with calculations at the B3LYP and HSE06 hybrid density functional theory (DFT) levels. We argue that the pentafulvene monomer unit has a unique character because...

Reproducibility, stability and the coupling between electrical and molecular properties are central challenges in the field of molecular electronics. The field not only needs devices that fulfill these criteria but they also need to be up-scalable to application size. In this work, few-molecule based electronics devices with reproducible electrical...

Acetylenic phosphaalkenes (APAs) are used as a novel type of ligands for the stabilization of gold nanoparticles (AuNP). As demonstrated by a variety of experimental and analytical methods, both structural features of the APA, that is, the PC as well as the CC units are essential for NP stabilization. The presence of intact APAs on the AuNP is de...

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A series of tentative single-molecule conductance switches which could be triggered by light were examined by computational means using density functional theory (DFT) with non-equilibrium Green's functions (NEGF). The switches exploit the reversal in electron counting rules for aromaticity and antiaromaticity upon excitation from the electronic gr...

Cyclohexane, with its well-defined conformers, could be an ideal force-controlled molecular switch if it were to display substantial differences in electronic and optical properties between its conformers. We utilize σ conjugation in heavier analogues of cyclohexanes (i.e. cyclohexasilanes) and show that 1,4-disubstituted cyclohexasilanes display c...

Oligomers of 1,4-disila/germa/stannacyclohexa-2,5-dienes as well as all-carbon 1,4-cyclohexadienes connected via E—E single bonds (E = C, Si, Ge, or Sn) were studied through quantum chemical calculations in an effort to identify conformationally flexible molecular wires that act as molecular “electrical cords” having conformer-independent conjugati...

Silicon is still the dominating material in microelectronics, yet primarily π- conjugated hydrocarbons are investigated in the field of single-molecule electronics even though linear oligosilanes are σ-conjugated. A drawback with the latter is their high conformational flexibility which strongly affects conductance. Here we report on a first princi...

Graphene nanogaps and nanopores show potential for the purpose of electrical DNA sequencing, in particular because single-base resolution appears to be readily achievable. Here, we evaluated from first principles the advantages of a nanogap setup with functionalized graphene edges. To this end, we employed density functional theory and the non-equi...

On the basis of first-principles density functional theory calculations, we propose a new molecular photoswitch which exploits a photochemical [1,3]-silyl(germyl) shift leading from a silane to a silene (a Si=C double bonded compound). The silanes investigated herein act as the OFF state, with tetrahedral saturated silicon atoms disrupting the conj...

Well-known conductive molecular wires, like cumulene or polyyne, provide a model for interconnecting molecular electronics circuit. In the recent experiment, the appearance of carbon wire bridging two-dimensional electrodes - graphene sheets - was observed [PRL 102, 205501 (2009)], thus demonstrating a mechanical way of producing the cumulene. In t...

Short chains containing a series of metal- molecule-nanoparticle nanojunctions are a nano-materials system with the potential to give electrical signatures close to those from single molecule experiments while enabling to build portable devices on a chip. Inelastic electron tunnelling spectroscopy (IETS) measurements provide one of the most charact...

By combining the Boltzmann transport equation with ab-initio electronic structure calculations, we obtain transport coefficients for boron-doped diamond. We find the temperature dependence of the resistivity and the hall coefficients in good agreement with experimental measurements. Doping in the samples is treated via the rigid band approximation...

Advances in materials research means that we find ourselves at the verge of constructing nano-scale devices capable of electrically addressing individual molecules in order to identify or utilize their electrical or electromechanical properties. An important application in life sciences would be electromechanical translocation of a DNA molecule thr...

The proposal was made that a graphene nanogap could be used to probe the transverse conductance of individual nucleotides in DNA to rapidly identify the associated base sequence. Experimentally, the characteristic drop in ionic current associated with translocation events of DNA passing through a graphene nanopore was measured. Using first-principl...

We present calculated interband transitions and effective masses for diamond from first principles including electron correlation effects via the GW-approximation. Our findings are in agreement with experiments, already the first iteration of the GW-scheme gives a direct gap at the gamma-point of 7.38 eV and a indirect gap of 5.75 eV close to exper...

Abstract The use of graphene electrodes with hydrogenated edges for solid-state nanopore-based DNA sequencing is proposed, and molecular dynamics simulations in conjunction with electronic transport calculations are performed to explore the potential merits of this idea. The results of the investigation show that, compared to the unhydrogenated sys...

Nanoelectrodes fabricated from graphene could potentially achieve the crucial single-nucleobase resolution required for novel nanopore-based approaches at DNA sequencing. The aspect of hydrogenated graphene edges has been explored by Ralph H. Scheicher, Ming Liu, and co-workers, on page 2674, through molecular-dynamics simulations and electronic-tr...

The fabrication of nanopores in atomically thin graphene has recently been achieved, and translocation of DNA has been demonstrated. Taken together with an earlier proposal to use graphene nanogaps for the purpose of DNA sequencing, this approach can resolve the technical problem of achieving single-base resolution in electronic nucleobase detectio...

We investigate the electrical transport properties of two hydrogen tautomer configurations of phthalocyanine (H2Pc) connected to cumulene and gold leads. Hydrogen tautomerization affects the electronic state of H2Pc by switching the character of molecular orbitals with the same symmetry close to the Fermi level. The near degeneracy between the HOMO...

We investigate the electrical transport properties of two hydrogen tautomer configurations of phthalocyanine (H2Pc) connected to cumulene and gold leads. Hydrogen tautomerization affects the electronic state of H2Pc by switching the character of molecular orbitals with the same symmetry close to the Fermi level. The near degeneracy between the HOMO...

In an attempt to realize third-generation whole-genome sequencing technologies, nanopores have been at the center of the research focus. Key issues with this approach involve how to slow down the translocation speed of DNA and how to achieve single-base resolution. We have previously proposed [arXiv:0708.4011; J. Phys. Chem. C 112, 3456 (2008)] the...

The application of graphene nanogaps for DNA sequencing has been proposed [H. W. Ch. Postma, Nano Lett. 10, 420 (2010)]. We used density functional theory and the non-equilibrium Green's function method to study the electron transport properties of nucleotides located inside a graphene nanogap. Our setup considered different positions and orientati...

We have studied the effect of double-functionalization on gold electrodes for improving nanopore-based DNA sequencing. The functionalizing molecular probes are respectively capable of temporarily forming hydrogen bonds with both the nucleobase part and the phosphate group of the target DNA, thus potentially minimizing the structural fluctuations of...

We propose using graphene electrodes with hydrogenated edges for solid-state nanopore-based DNA sequencing, and perform molecular dynamics simulations in conjunction with electronic transport calculations to explore the potential merits of this idea. The results of our investigation show that, compared to the unhydrogenated system, edge-hydrogenate...

We propose the use of bilayer graphene as nanoelectrodes for solid-state nanopore-based DNA sequencing, and perform molecular dynamics simulations and electrical transport property calculations to explore the potential merits of this proposal. The results of our investigation show that compared to single-layer graphene nanoelectrodes, bilayer graph...

We propose using characteristic transverse differential conductance for solid-state nanopore-based DNA sequencing and have explored this idea by performing molecular dynamics simulations on the translocation progress of single-stranded DNA molecule through the nanopore, and calculating the associated transverse differential conductance. Our results...

Aromatic molecules are central components of model systems for molecular electronics, with C-60 one of the most studied. Upon adsorption on (metallic) substrates a splitting of the frontier orbitals is commonly observed, with a strong dependence on substrate material, but little dependence on substrate structure. We report the detailed photoelectro...

A combination of electron beam lithography, photolithography and focused ion beam milling was used to create a nanogap platform, which was bridged by gold nanoparticles in order to make electrical measurements and assess the platform under ambient conditions. Non-functionalized electrodes were tested to determine the intrinsic response of the platf...

We propose an approach for nanopore-based DNA sequencing using characteristic transverse differential conductance. Molecular dynamics and electron transport simulations show that the transverse differential conductance during the translocation of DNA through the nanopore is distinguishable enough for the detection of the base sequence and can withs...

Using DFT based NEGF technique, we investigated electrical transport properties of the single-molecular switch, phthalocyanine (H2Pc), based on hydrogen tautomerization. The molecule is coupled to 1-D electrodes in the form of semi- infinite metallic chains of gold and carbon. Hydrogen tautomerization affects the electronic state of H2Pc by switchi...

We present first principles calculations of current-voltage characteristics (IVC) and conductance of Au(111):S2-cumulene-S2:Au(111) molecular wire junctions with realistic contacts. The transport properties are calculated using full self-consistent ab initio NEGF-DFT methods under external bias. The conductance of the cumulene wires shows oscillato...

We compare photoelectron spectra (PES) and theoretical densities-of-states of C(60)/Al(111), C(60)/Al(110) and C(60)/Al(100). The splitting observed on all three surfaces is attributed to final state charging. This splitting can also be used to improve estimates of the charging energy U of adsorbed molecules and as a criterion for the existence of...

We report current-voltage curves and conductance of cumulene molecular wire suspended between Au(111) surfaces via thiolate bonds with full self-consistent ab initio calculation under external bias. The conductance of cumulene wires shows oscillatory behavior depending on the number of carbon atoms. Among all conjugated oligomers, we find that odd-...

Practical utilization of the unique properties of graphene-based nanodevices requires establishing electrical contact to graphene flakes or graphene-cut nano-ribbons. Computational model of the contact region should simultaneously describe a significant area of the contact surface touching the graphene flake, and remain of a size tractable for mode...

With the aim of improving nanopore-based DNA sequencing, we explored the effects of functionalizing the embedded gold electrodes with purine and pyrimidine molecules. Hydrogen bonds formed between the molecular probe and target bases stabilize the scanned DNA unit against thermal fluctuations and thus greatly reduce noise in the current signal. The...

The conductance of monoatomic gold wires containing 3-7 gold atoms has been obtained from ab initio calculations. The transmission is found to vary significantly depending on the wire stretching and the number of incorporated atoms. Such oscillations are determined by the electronic structure of the one-dimensional (1D) part of the wire between the...

We study the variation of electron transmission through Au-S-benzene-S-Au junctions and related systems as a function of the structure of the Au:S contacts. For junctions with semi-infinite flat Au(111) electrodes, the highly coordinated in-hollow and bridge positions are connected with broad transmission peaks around the Fermi level, due to a broa...

We study the variation of electron transmission through Au-S-benzene-S-Au junctions and related systems as a function of the structure of the Au:S contacts. For junctions with semi-infinite flat Au(111) electrodes, the highly coordinated in-hollow and bridge positions are connected with broad transmission peaks around the Fermi level, due to a broa...

We use non-equilibrium Green's function DFT methods (TranSIESTA) to study the bonding-site dependence of the transmission through metal-molecule contacts in molecular junctions of type M-S-mol-S-M for a number of different molecular systems, mainly short molecules with DTB as a reference system, and also OPVn, n=3-5. For all systems on Au(111) surf...

We theoretically study the electronic transport in the monolayer of dithiolated phenylene vinylene oligomeres coupled to the (111) surfaces of gold electrodes. We use nonequilibrium Green's functions and density-functional theory implemented in the TranSIESTA package to obtain a full ab initio self-consistent description of the transport current th...

We theoretically study the electronic transport in the monolayer of dithiolated phenylene vinylene oligomeres coupled to the (111) surfaces of gold electrodes. We use non-equilibrium Green functions (NEGF) and density functional theory(DFT) implemented in the TranSIESTA package to obtain a full ab initio self-consistent description ofthe transport...

A computational study of the elementary building blocks for molecular electronics was presented. The interface between sulfur-terminated molecules and gold crystalline electrodes, called molecular alligator clips, was analyzed. Sulfur and selenium were adsorbed on Au (111) surface and sulfur film was hydrogenated along with computer simulations, wh...

For the binding of thiols to An, the Au-S interaction is decisive for the Geometry, bonding strength and transmissivity of the metal-molecule interface. Using ab initio methods we investigate the adsorption of sulfur (S) on the Au(111) surface for different coverages between 0.25 and 1.0 monolayers (ML). Corresponding geometries with adsorbed Se ar...

This chapter is not a review. Instead, the motivation for studying molecules as conductors is given and basic principles of the theoretical description and modeling are considered. We believe this presentation is useful, because such topics, are usually left out or barely scratched by the researchers involved, who think them trivial, thus making it...