Electronic Behavior Research Articles

Single-Electron Catalysis of Reversible Cycloadditions under Nanoconfinement.

Electron transfer (ET) is crucial in many chemical reactions, but its mechanism and role are hardly understood in nanobiotechnology due to the complexity of reaction species and pathways involved. By modulating and monitoring electron behavior at the single-molecule level, we can better understand the fundamental mechanisms and ways to control them for technological use. Here, we unravel a mechanism of single-electron catalysis under positively charged nanoconfinement. We demonstrate that both (2 + 2) and (4 + 4) cycloadditions can be catalyzed reversibly by a single electron. Key reaction pathways are discovered by monitoring sequential electrical signals in the cycloadditions through advanced single-molecule detection platforms. Experimental and theoretical results consistently demonstrate that combining single ET processes with nanoconfinement involving cucurbit[8]uril can lower the reaction energy barrier and promote reversible cycloaddition. Moreover, we show that the bias voltage can fine-tune ET processes and chemical equilibria in bond formation and cleavage. Our results provide a novel approach to elucidate, modulate, and design electron-involved reactions and functionalized devices.

Impact of electric field on donor energy and polarisability in GaAs variant toroidal quantum ring

ABSTRACT This study investigates the electronic properties of a GaAs Variant Toroidal Quantum Ring (VTQR) containing an off-centre donor impurity, focussing on the effect of an external electric field on donor energy and polarisability. Based on the effective mass approximation, we solved the Schrödinger equation using the finite difference method. The results show a typical effect at a toroidal angle of 180 ∘ , where the strength of the electric field leads to a decrease in the donor energy. Intriguingly, at toroidal angles of 90 ∘ and 60 ∘ , the donor energy increases with increasing field strength, indicating improved electron confinement. The probability density distributions shown reveal the location of the electron as influenced by the applied field. Furthermore, polarisability reaches its maximum around an angle of about 80 ∘ for all electric field strengths. This work provides a better understanding of the behaviour of electron in quantum ring systems and suggests potential for the engineering of tunable quantum devices.

Innovative Syntheses and Reactivity of Propiolamidines

Polydentate ligands with nitrogen donor atoms have possibly given rise to the largest group of coordination complexes described. Among these ligands, amidinates represent a nitrogenated version of carboxylates and allow the formation of complexes with most elements in the periodic table, adopting chelate or bridge coordination modes. The precursors of these ligands, amidines, can present an alkynyl group as the substituent of their central atom, R′N=C(C≡CR)NHR′, which provides an additional point of reactivity for these molecules, as well as a different electronic behavior compared to conventional amidines with alkyl groups on the central carbon atom of the amidine group. These propiolamidines have been obtained through classical stoichiometric organic synthesis procedures or, with greater atomic economy, through catalytic procedures based on Main Group, Transition, or Rare Earth metals. This work reviews these synthesis methods, as well as the reactivity in the obtention of new, more complex heterocyclic organic molecules.

Surface Engineering of Borophene as Next‐Generation Materials for Energy and Environmental Applications

This review provides an insightful and comprehensive exploration of the emerging 2D material borophene, both pristine and modified, emphasizing its unique attributes and potential for sustainable applications. Borophene's distinctive properties include its anisotropic crystal structures that contribute to its exceptional mechanical and electronic properties. The material exhibits superior electrical and thermal conductivity, surpassing many other 2D materials. Borophene's unique atomic spin arrangements further diversify its potential application for magnetism. Surface and interface engineering, through doping, functionalization, and synthesis of hybridized and nanocomposite borophene‐based systems, is crucial for tailoring borophene's properties to specific applications. This review aims to address this knowledge gap through a comprehensive and critical analysis of different synthetic and functionalisation methods, to enhance surface reactivity by increasing active sites through doping and surface modifications. These approaches optimize diffusion pathways improving accessibility for catalytic reactions, and tailor the electronic density to tune the optical and electronic behavior. Key applications explored include energy systems (batteries, supercapacitors, and hydrogen storage), catalysis for hydrogen and oxygen evolution reactions, sensors, and optoelectronics for advanced photonic devices. The key to all these applications relies on strategies to introduce heteroatoms for tuning electronic and catalytic properties, employ chemical modifications to enhance stability and leverage borophene's conductivity and reactivity for advanced photonics. Finally, the review addresses challenges and proposes solutions such as encapsulation, functionalization, and integration with composites to mitigate oxidation sensitivity and overcome scalability barriers, enabling sustainable, commercial‐scale applications.

(MgO)42 Nanocluster: An UV Active Magic Cluster in the (MgO)6n (n=1-9) Series under DFT Investigation

This study employs density functional theory (DFT) to investigate the electronic and optical properties of alkaline-earth magnesium oxide nanocluster series, namely (MgO)6n (n =1 to 9). As the number of (MgO)6 nanocluster unit increases in the (MgO)6n series, the electronic and optical behavior attributes a striking zigzag pattern. The analysis of energy gain in these clusters reveal a notably stable 'magic' nanocluster, namely (MgO)42. Additionally, our findings uncover UV-B active optical transitions in the (MgO)42 magic nanocluster, suggesting its promising potential for possible applications in optoelectronics. Further, the analysis of infrared spectra of the (MgO)42 magic nanocluster, combined with electronic properties cluster simulation, provides novel insights into its prospective synthesis. The promising properties of ultra-violet B active (MgO)42 nanocluster may further be explored for its low-dimensional customized assembled materials. Overall, this study advances the fundamental understanding of nanoscale MgO clusters, facilitating tailored design and versatile application across various technological domains.

Enhancing User Differentiation in the Electronic Personal Synthesis Behavior (EPSBV01) Algorithm by Adopting the Time Series Analysis

The progress of contemporary technology has rendered information systems essential in our everyday existence, underscoring the crucial necessity to safeguard information security and privacy. In password authentication, the Electronic Personal Synthesis Behaviour (EPSB) heightens the accuracy of authorizing an authenticated user based on three parameters: EPSBERROR, EPSBTime, and EPSBStyle. EPSBTime suffers from a lack of indicators associated with the legitimate user; containing only six indicators, there arose the need to adopt methods for generating additional reliable indicators by analyzing old indicators and generating new indicators related to the legitimate user. Therefore, this study aims to test the impact of adopting time series analysis in the EPSB time indicator on improving the differentiation of user legitimacy in the case of password-stolen attacks. The research methodology, which involves analyzing and evaluating existing authentication methods in web-based systems, is a key component of this study. The study is divided into stages, with the first phase focusing on enhancing the existing EPSB model, the second phase implementing EPSBalgorithmV01, and the final stage ensuring validation. Thus, two preliminary experiments were conducted with 22 users from January 13 to February 1, 2024. The final phase involved comparing EPSBV01's accuracy in determining unauthorized users before and after using the ARIMA method. Thus, the EPSBV01algorithm successfully identified 17 unauthorized users during a stolen password attack simulation, outperforming the normal EPSB by 22.73%. Doi: 10.28991/ESJ-2025-09-01-014 Full Text: PDF

Intermolecular naphthylamine cyclization–based synthesis of bandgap-modulated carbon dots for multicolor light-emitting diodes

Owing to their tunable optical properties, N-doped carbon dots (CDs) have a broad scope of optoelectronic applications. However, the difficulty of precisely controlling nitrogen incorporation limits our understanding of its impact on CD electronic structure and emission behavior. To address this gap, N-doped CDs with tunable bandgaps are herein synthesized via the solvothermal carbonization of 1-naphthylamine in the presence of a controlled amount of nitric acid to obtain single-source emitters with two distinct emission wavelengths. The amount of nitric acid determines the extent of nitrogen incorporation through the intermolecular cyclization of 1-naphthylamine and, hence, the proportions of pyrrolic/pyridinic N-heterocycles (red emission, ∼600 nm) and polycyclic aromatic hydrocarbons (blue emission, ∼400 nm). For a practical utility demonstration, the prepared N-doped CDs are used to fabricate high-color-purity multicolor light-emitting diodes. By establishing a correlation between nitrogen incorporation modes and photophysical properties, this study paves the way for the rational design of advanced N-doped CDs for next-generation optoelectronic devices.

ASUGNN: an asymmetric-unit-based graph neural network for crystal property prediction

Material properties can often be derived directly from fundamental equations governing electron behavior. In this study, we present an open-source asymmetric-unit-based graph neural network designed to capture atomic patterns and their corresponding electron distributions. By coarse-graining sites belonging to conjugate subgroups and analyzing reciprocal space through powder X-ray diffraction patterns, our model predicts key physical properties, including formation energy, band gap, bulk modulus and metal/non-metal classification. Our method demonstrates exceptional predictive accuracy for properties calculated using density functional theory across the Materials Project dataset. Our approach is compared with state-of-the-art models and exhibits impressively low error rates in zero-shot predictions.

Advances and Challenges in SnTe-Based Thermoelectrics.

SnTe-based thermoelectric materials have attracted significant attention for their exceptional performance in mid-to-high temperature ranges, positioning them as promising candidates for thermoelectric power generation. However, their efficiency is constrained by challenges related to electronic structure, defect chemistry, and phonon behavior. This review comprehensively summarizes advancements in SnTe thermoelectric materials and devices over the past five years, focusing on strategies to address these limitations. Key approaches include defect regulation, carrier transport optimization, and phonon engineering to enhance electrical conductivity, reduce thermal conductivity, and improve overall thermoelectric conversion efficiency. The review highlights breakthroughs in fabrication methods, doping and alloying, composite designs, and the development of novel nanostructures, with particular emphasis on 2D SnTe materials such as monolayers, bilayers, and thin films, which offer new opportunities for performance enhancement. Additionally, it provides an overview of SnTe-based thermoelectric devices, covering fabrication techniques, performance optimization, stability, and flexible device development. Despite significant progress, challenges remain in developing n-type SnTe materials, optimizing interfaces, ensuring long-term stability, and maximizing conversion efficiency. This review fills gaps in the existing literature and offers valuable insights and guidance for future research aimed at improving thermoelectric properties, advancing device integration, and driving the commercial viability of SnTe-based materials for practical applications.

Structural and topological analysis of thiosemicarbazone-based metal complexes: computational and experimental study of bacterial biofilm inhibition and antioxidant activity

The structural and electronic behavior of thiosemicarbazone (TSC)-based metal complexes of Mn (II), Fe (II), and Ni (II) have been investigated. The synthesized metal complexes were characterized using elemental analysis, magnetic susceptibility, molar conductivity, FTIR, and UV–Vis spectroscopy, the computational path helped with further structural investigation. The solubility test on the TSC and its complexes revealed their solubility in most organic solvents. DFT computational analysis was performed, and quantum reactivity parameters of the octahedral optimized complexes were calculated to describe the reactivity via the stability states of the synthesized complexes. FMOs map was generated to confirm similar findings and MEP analysis was applied to elaborate the important electrophilic and nucleophilic sites on the studied surfaces. Also, other important topological analyses such as electron localization function and reduced density gradient, to establish the favorable noncovalent interactions, were studied. In silico molecular docking approach was studied against the gram-positive bacteria Bacillus cereus to predict the potent inhibition behavior of the studied complexes. The findings summarized the inhibition prediction of the most interactive [NiL2Cl2], then [FeL2Cl2] complexes as confirmed by the binding energy values (− 7.1 kacl/mol and − 6.4 kacl/mol, respectively). Another In silico results, with gram-positive bacteria (S. aureus), estimated similar results of the experimental finding, where [MnL2Cl2] (− 9.2 kcal/mol) is the more effective predicted antibacterial inhibitor. Fluorescence microscopy was used to examine the inhibition of bacterial biofilm, and the DPPH assay was used to measure antioxidant activity, followed by an understanding of the behavior of the current complexes toward free radicals’ removal. The findings observed less aggregated bacterial strains covered with the studied complexes leading to less dense biofilm covering.

The BeP2 monolayer exhibits ultra-high and highly anisotropic carrier mobility and 29.3% photovoltaic efficiency.

Two-dimensional materials with a combination of a moderate bandgap, highly anisotropic carrier mobility, and a planar structure are highly desirable for nanoelectronic devices. This study predicts a planar BeP2 monolayer with hexagonal symmetry that meets the aforementioned desirable criteria using the CALYPSO method and first-principles calculations. Calculations of electronic properties demonstrate that the hexagonal BeP2 monolayer is an intrinsic semiconductor with a direct band gap of approximately 0.94 eV and this direct bandgap characteristic is maintained under strain. The mobilities of hexagonal BeP2 are electron-dominated, reaching ∼105 cm2 V-1 s-1, which is two orders of magnitude higher than the mobility of holes. The high carrier mobility results from the small deformation potential constant, which arises from the unique decoupling behavior of electrons in the valence and conduction bands. Furthermore, our calculations reveal that the photovoltaic efficiency of hex-BeP2 is as high as 29.3%, which is comparable to those of well-known thin-film solar cell absorbers, thanks to its high visible light absorption coefficient of ∼105 cm-1 and its direct bandgap feature.

Silver nanoparticle-induced interface dipole and energy band bending in graphene quantum dot/pentacene FETs: memory window compromise and current modulation

ABSTRACT The introduction of graphene quantum dots (GQDs) in a pentacene field effect transistor (FET) device structure notably improved the on/off ratio, demonstrating a significant memory window. This indicates that GQDs are effective in enhancing carrier retention properties. However, the subsequent introduction of Ag nanoparticles (NPs) between the pentacene layer and GQDs led to a significant decrease in the memory window and a far smaller on/off ratio. This decrease is primarily attributed to an increase in the “off” current, suggesting a detrimental impact of Ag NPs on the device performance. The formation of an interface dipole at the Ag NPs-GQDs interface appears to be the main factor behind this effect, influencing the energy band bending and altering the flat band energy. The integration of Ag NPs into the device not only modifies the threshold voltage and elevates the “off” current through interface dipole effects, but also considerably diminishes the “on” current. This reduction is attributed to the dual influences of reduced carrier concentration resulting from screening phenomena and the obstruction of charge movement caused by interfacial scattering. This twofold effect on both the “on” and “off” currents underscores the complex influence of Ag NPs in regulating the electronic behavior of the FET device.

Direct Observation of Dipole Interlocking Effect Occurrence in Two-Dimensional Ferroelectricity.

The electric dipole in materials is closely associated with their electronic transport, optical properties, and mechanical behavior. Here, we have employed the differential phase contrast (DPC) technique of the scanning transmission electron microscopy technique (STEM) to directly analyze the local electric dipole at the sub-Angstrom scale. By utilizing DPC-STEM technology, we successfully visualized the ferroelectric polarization of van der Waals material 3R α-In2Se3 and directly confirmed the dipole interlocking effect (DIE) between in-plane (IP) and out-of-plane (OOP) polarizations. Through density functional theory (DFT) calculations and structural analysis, we discovered that this DIE is caused by the central asymmetry of the middle Se atoms of each monolayer and that the reversal of polarization is accompanied by the emergence of an intermediate phase, β-In2Se3. Leveraging the DIE, we developed a multidirectional ferroelectric memristor that can effectively modulate the IP polarization by applying an OOP pulse voltage.

Promising mechanical, electronic and piezoelectric properties of grapheneplus-like BCN monolayer: insights from first-principles.

Two-dimensional (2D) carbon allotropes, together with their binary and ternary counterparts, have attracted substantial research interest due to their peculiar geometries and properties. Among them, grapheneplus, a derivative of penta-graphene, has been proposed to exhibit unusual mechanical and electronic behaviour. In this work, we perform a comprehensive first-principles study on its isoelectronic and isostructural analogue, a grapheneplus-like BCN (gp-BCN) monolayer. It is found that this gp-BCN system exhibits robust structural stability from energetic, dynamic, thermal, and mechanical perspectives. A remarkable anisotropy is observed in its mechanical behaviour, which even presents in-plane auxeticity with a high negative Poisson's ratio of -0.3. Different from the semimetallic grapheneplus one, the gp-BCN monolayer is a semiconductor with a direct band gap of 3.23 eV. High electron mobilities up to 103 cm2 V-1 s-1 appear in the gp-BCN system, which are one to two orders of magnitude greater than the hole mobilities. Furthermore, due to the breaking of inversion symmetry, the gp-BCN monolayer exhibits spontaneous out-of-plane polarization, yielding prominent out-of-plane piezoelectric responses that are comparable to those of Janus MoSSe, WSSe and H-decorated BN systems. Our study demonstrates that the BCN analogue of grapheneplus possesses promising mechanical, electronic, and piezoelectric properties, rendering it promising for applications in nanoelectronics and mechanical nanosensors.

Dipole-Modulated Carrier Dynamics and Charge Transport Behavior of Ligand-Protected Metal Chalcogenide Nanoclusters.

Atomically precise nanoclusters, distinguished by their unique nuclearity- and structure-dependent properties, hold great promise for applications of energy conversion and electronic transport. However, the relationship between ligands and their properties remains a mystery yet to be unrevealed. Here, the influence of ligands on the electronic structures, optical properties, excited-state dynamics, and transport behavior of Re12S16 dimer clusters with different ligands is explored using density functional theory combined with time-domain nonadiabatic molecular dynamic simulations. The correlation between ligands and the excited-state dynamics of nanoclusters is elucidated. The ligand replacement introduces a built-in electric field at the dimer interface, inhibiting the recombination of excited carriers and increasing the voltage threshold. This study paints a physical picture of the ligand effect on nanoclusters in terms of geometric configuration, electronic structure, optical properties, carrier dynamics, and transport behavior, paving a pathway toward their applications in optoelectronic materials.

Adsorption of lithium, sodium, gallium, and sulfur atoms onto a GaS monolayer

Abstract Hexagonal gallium sulfide (GaS) monolayer is a very promising monochalcogenide for applications such as electronics, optoelectronics, and catalysts. The adsorption and the diffusion of lithium (Li), sodium (Na), gallium (Ga), and sulfur (S) atoms onto the 2 × 2-GaS hexagonal monolayer are investigated using density functional theory (DFT), along with atomic pseudopotentials. The values of the calculations for the adsorption energy show that the energetically most favorable site for the Li, Na, and Ga adsorbates is the H site, while the most energetically favorable site for the S adsorbate is the TS site. The values calculated for the adsorption energy at the energetically most favorable sites for the Li, Na, Ga, and S atomic adsorbates are −1.853 eV, −1.378 eV, −1.028 eV, and −1.525 eV, respectively. Analysis of the structural properties revealed that after the adsorption process, the GaS+ads system maintains its structure and geometry, since the lattice constants and the lGa-Ga, lGa-S, and lS-S bond lengths do not change significantly with respect to the pristine monolayer. The diffusion of Li, Na, Ga, and S atoms on the 2 × 2-GaS monolayer’s surface shows energy barriers of 28 meV, 40 meV, 72 meV, and 161 meV, respectively. From the total density of states (DOS), it is established that in all cases the GaS+ads monolayer system acquires metallic behavior. Finally, analysis of the Bader charge of the GaS+ads system just at the energetically most favorable sites shows that the Li and Na atoms transfer charge to the monolayer (cations), becoming ionized, while the Ga and S atoms transfer and gain charge from the monolayer, respectively, becoming partially ionized. This electronic behavior makes the GaS monolayer a promising material for use as an anode in batteries.

Ptn (n = 1, 3, and 4) Cluster-Modified MoSe2 Nanosheets: A Potential Sensing and Scavenging Candidate for Lithium-Ion Battery State Characteristic Gases.

Realizing reliable online detection of characteristic gases (H2, C2H4, CO, and CO2) in lithium-ion batteries is crucial to maintain the safe and stable operation of power equipment and new energy storage power plants. In this study, transition metal Ptn (n = 1, 3, and 4) clusters are attached to MoSe2 nanosheets for the first time based on density functional theory using the perfect crystalline facet modification method, and the adsorption characteristics and electronic behaviors of H2, C2H4, CO, and CO2 are investigated and enhanced. The results show that Ptn (n = 1, 3, and 4) is reliably chemically connected to the substrate without any significant deformation of the geometry. The adsorption properties as well as the band gap, DOS, and LUMO-HOMO are optimized for the modified Gas/Ptn (n = 1, 3, and 4)-MoSe2 system. The large electronic states near the Fermi level are further activated by the modification process, and Pt-MoSe2 and Pt4-MoSe2 can serve as battery state characteristic gas sensors suitably according to the detection needs of specific target gases, whereas Pt3-MoSe2 can be used as a good adsorbent for effective and reliable scavenging of battery state characteristic gases and is further applied to energy and power equipment and new energy storage power plants.

In-Plane Anisotropy in van der Waals NiTeSe Ternary Alloy.

The anisotropic properties of materials profoundly influence their electronic, magnetic, optical, and mechanical behaviors and are critical for a wide range of applications. In this study, the anisotropic characteristics of Ni-based van der Waals materials, specifically NiTe2 and its alloy NiTeSe, utilizing a combination of comprehensive scanning tunneling microscopy (STM), angle-resolved photoemission spectroscopy (ARPES), and density functional theory (DFT) calculations, are explored. Unlike 1T-NiTe2, which exhibits trigonal in-plane symmetry, the substitution of Te with Se in NiTe2 (resulting in the NiTeSe alloy) induces a pronounced in-plane anisotropy. This anisotropy is clear in the STM topographs, which reveal a distinct linear order of charge distribution. Corroborating these observations, ARPES measurements and DFT calculations reveal an anisotropic Fermi surface centered at the point, which is notably elongated along the ky direction, leading to directional variations in in-plane carrier velocities. Consequently, the Fermi velocity is highest along the kx direction where the linear charge distribution aligns in real space and is lowest along the ky direction. These findings offer valuable insights into the tunability of anisotropic properties in ternary transition metal dichalcogenide systems, highlighting their potential applications in the development of anisotropic electronic and optoelectronic devices.

Altermagnetism: A Chemical Perspective.

Altermagnets have been recently introduced as a classification of collinear, spin compensated magnetic materials that host net-zero magnetization yet display some electronic behaviors typically associated with noncompensated magnetic materials like ferromagnets. The emergence of such properties are a consequence of spin-split bands that arise under specific symmetry conditions in the limit of zero spin-orbit coupling. In this Perspective, we summarize the fundamental criteria for realizing an altermagnetic phase and present a qualitative electronic band structure derivation and symmetry analysis through chemical principles. We then discuss the properties that make altermagnets distinctive candidates for charge-to-spin conversion elements in spintronic devices and provide a brief review of some altermagnetic candidate materials. Finally, we discuss future directions for altermagnetism and highlight opportunities for chemists to advance this emerging field.

Programmable Electromagnetic Wave Absorption via Tailored Metal Single Atom-Support Interactions.

Metal single atoms (SA)-support interactions inherently exhibit significant electrochemical activity, demonstrating potential in energy catalysis. However, leveraging these interactions to modulate electronic properties and extend application fields is a formidable challenge, demanding in-depth understanding and quantitative control of atomic-scale interactions. Herein, in situ, off-axis electron holography technique is utilized to directly visualize the interactions between SAs and the graphene surface. These interactions facilitate the formation of dispersed nanoscale regions with high charge density and are highly sensitive to external electromagnetic (EM) fields, resulting in controllable dynamic relaxation processes for charge accumulation and restoration. This leads to customized dielectric relaxation, which is difficult to achieve with current band engineering methods. Moreover, these electronic behaviors are insensitive to elevated temperatures, having characteristics distinct from those of typical metallic or semiconducting materials. Based on these results, programmable EM wave absorption properties are achieved by developing a library of SA-graphene materials and precisely controlling SA-support interactions to tailor their responses to EM waves in terms of frequency and intensity. This advancement addresses the customized anti-EM interference requirements of electronic components, greatly enhancing the development of integrated circuits and micro-nano chips. Future efforts will concentrate on manipulating atomic interactions in SA-support, potentially revolutionizing nanoelectronics and optoelectronics.