Abstract Optoelectronic applications require materials both responsive to objective photons and able transfer carriers, so new two‐dimensional (2D) semiconductors with appropriate band gaps high mobilities are highly desired. A broad range of a 2D semiconductor family, composed monolayer Group 15 elements (phosphorene, arsenene, antimonene, bismuthene) is presented. The calculated binding energies phonon dispersions allotropes exhibit thermodynamic stability. energy semiconducting monolayers...

Graphene is an important material with potential application in spintronics. Edge-modified zigzag graphene nanoribbons (ZGNR) are investigated density functional theory. The modifications realized by saturating the dangling edge bonds different terminal groups, such as H, NH2, NO2, and CH3. Such modification has a significant impact on ZGNR electronic structure. Half-metallicity observed when terminated NO2 groups at one CH3 other side. Free energy analysis suggests that edge-modification...

Abstract Optoelectronic applications require materials both responsive to objective photons and able transfer carriers, so new two‐dimensional (2D) semiconductors with appropriate band gaps high mobilities are highly desired. A broad range of a 2D semiconductor family, composed monolayer Group 15 elements (phosphorene, arsenene, antimonene, bismuthene) is presented. The calculated binding energies phonon dispersions allotropes exhibit thermodynamic stability. energy semiconducting monolayers...

A novel general method of describing the spin-lattice interactions in magnetic solids was proposed terms first principles calculations. The spin exchange and Dzyaloshinskii-Moriya as well their derivatives with respect to atomic displacements can be evaluated efficiently on basis density functional calculations for four ordered states. By taking into consideration spin-spin interactions, phonons, coupling between them, we show that ground state structure a representative spin-frustrated...

Two-dimensional (2D) ferromagnetic semiconductors have been recognized as the cornerstone for next-generation electric devices, but development is highly limited by weak coupling and low Curie temperature (TC). Here, we reported a general mechanism which can significantly enhance in 2D without introducing carriers. On basis of double-orbital model, revealed that superexchange-driven ferromagnetism closely related to virtual exchange gap, lowering this gap isovalent alloying (FM) coupling....

At B3LYP level of theory, we predict that the half-metallicity in zigzag edge graphene nanoribbon (ZGNR) can be realized when an external electric field is applied across ribbon. The critical decreases with increase ribbon width to induce half-metallicity. Both spin polarization and are removed state electrons fully transferred from one side other under very strong field. range which ZGNR remains half-metallic increases width. Our study demonstrates a rich field-induced behavior, may lead...

The realization of multiferroics in nanostructures, combined with a large electric dipole and ferromagnetic ordering, could lead to new applications, such as high-density multistate data storage. Although have been broadly studied for decades, ferroelectricity is rarely explored, especially two-dimensional (2D) systems. Here we report the discovery 2D layered transition-metal halide On basis first-principles calculations, reveal that charged CrBr_{3} monolayer exhibits in-plane...

New ternary composites of MnO2 nanorods, polyaniline (PANI) and graphene oxide (GO) have been prepared by a two-step process. The 100 nm-long nanorods with diameter ~20 nm are conformably coated PANI layers fastened between GO layers. incorporated electrode exhibits significantly increased specific capacitance than PANI/GO binary composite in supercapacitors. 70% highest reaching 512 F/g outstanding cycling performance, ~97% retained over 5000 cycles. approach offers an effective solution to...

Metastable structural polymorphs can have superior properties and applications to their thermodynamically stable phases, but the rational synthesis of metastable phases is a challenge. Here, new strategy for stabilizing using surface functionalization demonstrated example formamidinium lead iodide (FAPbI3) perovskite, which at room temperature (RT) holds great promises in solar light-emitting applications. We show that, through ligand during direct solution growth RT, pure FAPbI3 cubic...

High-temperature ferromagnetic two-dimensional (2D) materials with flat surfaces have been a long-sought goal due to their potential in spintronics applications. Through comprehensive first-principles calculations, we show that the recently synthesized MoN2 monolayer is such material; it Curie temperature of nearly 420 K, which higher than any 2D magnetic studied date. This novel property, made possible by electron-deficient nitrogen ions, render transition-metal dinitrides monolayers unique...

van der Waals materials possess an innate layer degree of freedom and thus are excellent candidates for exploring emergent two-dimensional ferroelectricity induced by interlayer translation. However, despite being theoretically predicted, experimental realization this type is scarce at the current stage. Here, we demonstrate robust sliding in semiconducting 1T^{'}-ReS_{2} multilayers via a combined study theory experiment. Room-temperature vertical observed with number N≥2. The electric...

Developing efficient hydrogen oxidation reaction (HOR) electrocatalysts in alkaline media is of great significance for anion exchange membrane fuel cells. Herein, we report the synthesis hollow colloidosomes composed Ru nanocrystals based on a novel gas/liquid interface self-assembly strategy. Structural characterizations reveal that much defects are present building block (Ru nanocrystals) colloidosomes. Theoretical calculations suggest structure can optimize adsorption binding energy...

The Fe-embedded N-doped graphene (Fe–N–C) is the most representative single atom catalyst (SAC) that has shown great potentiality in electrocatalysis, such as oxygen reduction reaction (ORR) and evolution (OER). However, active moiety of Fe–N–C still elusive due to contradictory experimental results. Moreover, early simulations mainly focus on thermodynamic potential adsorbates, while effect spin multiplicity receives little attention. To explore role we employ constant-potential density...

We have studied structural, electronic, and magnetic properties of the graphene-like ZnO monolayer doped with nonmetal species using first-principles calculations. Particular attention has been placed on one or two oxygen atoms per supercell substituted by carbon, boron, nitrogen atoms. find that atom a carbon boron is ferromagnetic (FM) half metal (HM), while FM semiconductor. Upon vary, depending distance between impurities. Two neighboring in form dimer pairs, which convert into an n-type...

Diamond silicon (Si) is the leading material in current solar cell market. However, diamond Si an indirect band gap semiconductor with a large energy difference (2.3 eV) between direct and gap, which makes it inefficient absorber of light. In this work, we develop novel inverse structure design approach based on particle swarming optimization algorithm to predict metastable phases better optical properties than Si. Using our new method, cubic Si(20) phase quasidirect gaps 1.55 eV, promising...

Although graphitic C3N4 (g-C3N4) has been demonstrated to be a potential candidate for solar cell absorber and photovoltaic materials, the application limited by low photoconversion efficiency in visible range. Here, we explored that g-C3N4 bilayer much better visible-light adsorption than single layer via first-principles calculations, calculated optical threshold of significantly shifts downward 0.8 eV, which is induced interlayer coupling. Additionally, also found energy gap can...

The quantum anomalous Hall (QAH) effect is a novel topological spintronic phenomenon arising from inherent magnetization and spin-orbit coupling. Various theoretical experimental efforts have been devoted in search of robust intrinsic QAH insulators. However, up to now, it has only observed Cr or V doped (Bi,Sb)2Te3 film experiments with very low working temperature. Based on the successful synthesis transition metal halides, we use first-principles calculations predict that RuI3 monolayer...

The ferroelectric polarization of triangular-lattice antiferromagnets induced by helical spin-spiral order is not explained any existing model magnetic-order-driven ferroelectricity. We resolve this problem developing a general theory for the and then evaluating coefficients needed to specify on basis density functional calculations. Our correctly describes ferroelectricity driven incorporates known models as special cases.

Abstract Graphene and its composite hydrogels with interconnected three-dimensional (3D) structure have raised continuous attention in energy storage. Herein, we describe a simple hydrothermal strategy to synthesize 3D CoS/graphene hydrogel (CGH), which contains the reduction of GO sheets anchoring CoS nanoparticles on graphene sheets. The formed special endows this high electrochemical performance. Remarkably, obtained CGH exhibits specific capacitance ( C s ) 564 F g −1 at current density...

Sandwich-structured hierarchical (MnO₂, PPy)/rGO nanosheets composites exhibited a maximum specific capacitance of 404 F g⁻¹ and ∼91% retention over 5000 cycling.

Abstract Encapsulation strategies are widely used for alleviating dissolution and diffusion of polysulfides, but they experience nonrecoverable structural failure arising from the repetitive severe volume change during lithium−sulfur battery cycling. Here we report a methodology to construct an electrochemically recoverable protective layer polysulfides using electrolyte additive. The additive nitrogen-doped carbon dots maintain their “dissolved” status in at full charge state, some them...

Controlling magnetism of two-dimensional multiferroics by an external electric field provides special opportunities for both fundamental research and future development low-cost electronic nanodevices. Here, we report a general scheme realizing magnetic phase transition in 2D type-I multiferroic systems through the reversal ferroelectric polarization. Based on first-principles calculations, demonstrate that single-phase multiferroic, namely, ReWCl_{6} monolayer, exhibits two different...

The electronic properties of a graphene–boron nitride (G/BN) bilayer have been carefully investigated by first-principles calculations. We find that the energy gap graphene is tunable from 0 to 0.55 eV and sensitive stacking order interlayer distances G/BN bilayer. By structure analysis tight-binding simulations, we conclude charge redistribution within transfer between BN layers determine graphene, through modification on-site difference carbon p orbitals at two sublattices. On basis...

The unprecedented applications of two-dimensional (2D) atomic sheets in spintronics are formidably hindered by the lack ordered spin structures. Here we present first-principles calculations demonstrating that recently synthesized dimethylmethylene-bridged triphenylamine (DTPA) porous sheet is a ferromagnetic half-metal and size band gap semiconducting channel roughly 1 eV, which makes DTPA an ideal candidate for spin-selective conductor. In addition, robust half-metallicity 2D under...