Quantum interference enhances the performance of single-molecule transistors

Nature Nanotechnology, Год журнала: 2024, Номер 19(7), С. 986 - 992

Опубликована: Март 25, 2024

Quantum effects in nanoscale electronic devices promise to lead new types of functionality not achievable using classical components. However, quantum behaviour also presents an unresolved challenge facing electronics at the few-nanometre scale: resistive channels start leaking owing tunnelling. This affects performance transistors, with direct source-drain tunnelling degrading switching ratios and subthreshold swings, ultimately limiting operating frequency due increased static power dissipation. The usual strategy mitigate has been increase device complexity, but theory shows that if can be exploited molecular-scale electronics, this could provide a route lower energy consumption boost performance. Here we demonstrate these experimentally, showing how molecular transistors is improved when channel contains two destructively interfering waves. We use zinc-porphyrin coupled graphene electrodes three-terminal transistor >10

Язык: Английский

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Ballistic Conductance through Porphyrin Nanoribbons

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(6), С. 3651 - 3659

Опубликована: Фев. 1, 2024

The search for long molecular wires that can transport charge with maximum efficiency over many nanometers has driven electronics since its inception. Single-molecule conductance normally decays length and is typically far below the theoretical limit of G0 (77.5 μS). Here, we measure conductances a family edge-fused porphyrin ribbons (lengths 1–7 nm) display remarkable behavior. low-bias high across whole series. Charging molecules in situ results dramatic realignment frontier orbitals, increasing to 1 (corresponding current 20 μA). This behavior most pronounced longer due their smaller HOMO–LUMO gaps. conductance-voltage traces frequently exhibit peaks at zero bias, showing energy level resonance Fermi level. work lays foundations long, perfectly transmissive, technological potential.

Язык: Английский

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Thermoelectricity in Molecular Tunnel Junctions

Chemical Reviews, Год журнала: 2025, Номер unknown

Опубликована: Фев. 5, 2025

The growing interest in thermoelectric energy conversion technologies has recently extended to the molecular scale, with tunnel junctions emerging as promising platforms for harvesting from heat a quantum-tunneling regime. This Review explores advances thermoelectricity within junctions, highlighting unique ability of these exploit charge tunneling and controlled structure enhance performance. Molecular thermoelectrics, which bridge nanoscale material design applications, utilize mechanisms, such coherent hopping processes, including incoherent pathways, facilitate conversion. Complementing mechanisms is an array high-precision fabrication techniques single-molecule break large-area liquid metal-based systems, each tailored optimize transfer properties. With novel strategies incorporation electron-dense ligands, customizable anchor groups, advanced junction architectures, hold promise addressing challenging targets thermoelectricity. focuses on theoretical models, experimental methodologies, principles aimed at understanding function enhancing

Язык: Английский

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Charge and Spin Transfer Dynamics in a Weakly Coupled Porphyrin Dimer

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(31), С. 21476 - 21489

Опубликована: Июль 23, 2024

The dynamics of electron and spin transfer in the radical cation photogenerated triplet states a tetramethylbiphenyl-linked zinc-porphyrin dimer were investigated, so as to test relevant parameters for design single-molecule valve creation novel platform photogeneration high-multiplicity states. We used combination multiple techniques, including variable-temperature continuous wave EPR, pulsed proton electron-nuclear double resonance (ENDOR), transient optical spectroscopy. conclusions are further supported by density functional theory (DFT) calculations comparison reference compounds. low-temperature cw-EPR room-temperature near-IR spectra monocation demonstrate that is spatially localized on one side at any point time, not coherently delocalized over both porphyrin units. EPR 298 K reveal rapid hopping between sites via reversible intramolecular transfer. hyperfine interactions modulated can be quantified using ENDOR This allowed simulation with two-site exchange model provided information temperature-dependence rate. rates range from about 10.0 MHz 200 53.9 K. activation enthalpies Δ

Язык: Английский

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Long-Range Charge Transport in Molecular Wires

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(47), С. 32206 - 32221

Опубликована: Ноя. 14, 2024

Long-range charge transport (LRCT) in molecular wires is crucial for the advancement of electronics but remains insufficiently understood due to complex mechanisms and their dependencies on structure. While short-range typically dominated by off-resonant tunneling, which decays exponentially with length, recent studies have highlighted certain structures that facilitate LRCT minimal attenuation over several nanometers. This Perspective reviews latest progress understanding LRCT, focusing chemical designs enable this phenomenon. Key strategies include π-conjugation, redox-active centers, stabilization radical intermediates, support through such as coherent resonant tunneling or incoherent hopping. We discuss how effects structure, temperature influence transport, highlight emerging techniques like Seebeck effect distinguishing between mechanisms. By clarifying principles behind outlining future challenges, work aims guide design systems capable sustaining efficient long-distance thereby paving way practical applications beyond.

Язык: Английский

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Carbon Nanohoops: Multiple Molecular Templates for Exploring Spectroscopic, Electronic, and Thermoelectric Properties

ACS Omega, Год журнала: 2024, Номер 9(9), С. 10610 - 10620

Опубликована: Фев. 22, 2024

A combination of density functional theory (DFT) methods and quantum transport (QTT) has been used to investigate the spectroscopic, electronic, thermoelectric properties carbon nanohoop molecules with different molecular templates. The connectivity type, along inherent strain, impacts behavior creates a destructive interference (DQI), which proves itself be powerful strategy enhance these molecules, making them promising candidates for applications.

Язык: Английский

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Connections to the Electrodes Control the Transport Mechanism in Single‐Molecule Transistors

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(16)

Опубликована: Фев. 27, 2024

When designing a molecular electronic device for specific function, it is necessary to control whether the charge-transport mechanism phase-coherent transmission or particle-like hopping. Here we report systematic study of charge transport through single zinc-porphyrin molecules embedded in graphene nanogaps form transistors, and show that depends on chemistry molecule-electrode interfaces. We van der Waals interactions between anchoring groups yield characteristic Coulomb blockade with incoherent sequential hopping, whereas covalent amide bonds give intermediately strongly coupled single-molecule devices display coherent transmission. These findings demonstrate importance interfacial engineering circuits.

Язык: Английский

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Theoretical and modelling investigation of pendant groups effect on quantum interference for single-molecule junctions

RSC Advances, Год журнала: 2024, Номер 14(21), С. 14704 - 14715

Опубликована: Янв. 1, 2024

Quantum interference (QI) is one of the most important phenomena that affects charge transport through single molecules. The effect a constructive and destructive quantum on electronic, thermoelectric spectroscopic properties oligo(phenyleneethynylene) based-molecular junctions has been investigated using combination density functional theory (DFT) methods, tight binding (Hückel) modelling (TBHM) (QTT). Molecules with carbonyl, diphenyl, ethane ethynylferrocene substituents show (DQI), which enhances these molecules making them promising materials for applications.

Язык: Английский

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Synthesis of Ni^II porphyrin—Ni^II 5,15-diazaporphyrin hybrid tapes

Chemical Science, Год журнала: 2024, Номер 15(26), С. 10207 - 10213

Опубликована: Янв. 1, 2024

Porphyrin-diazaporphyrin hetero oligomers were constructed through a Suzuki–Miyaura cross-coupling reaction. Hetero nanotapes exhibiting strong NIR absorption obtained via further oxidation of these oligomers.

Язык: Английский

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Prolonged Exciton Lifetime Is Achieved in Porphyrin Nanoring by Template Engineering: A Nonadiabatic Tight Binding Approach

The Journal of Physical Chemistry Letters, Год журнала: 2024, Номер 15(17), С. 4737 - 4744

Опубликована: Апрель 25, 2024

Porphyrin nanoring has been attracting immense attention due to its light harvesting capacity and potential applications in optical, catalysis, sensor, electronic devices. We demonstrate by nonadiabatic quantum dynamics simulations that the photovoltaic efficiency can be enhanced template engineering. Altering hexadentate (T6) with two tridentate templates (2T3) within porphyrin ring (P6) cavity accelerated electron transfer twice suppressed electron–hole recombination nearly three times. The atomistic tight-binding simulation rationalized different localizations of charge band edge states, changes coupling, alteration coherence, involvement diverse electron–phonon vibrational modes. Further 2T3 more strongly hold P6 than T6, reducing structural fluctuation. As a result, coupling becomes weaker suppresses carrier recombination. Current presents engineering strategy enhance exciton lifetime along ultrafast separation, crucial factors for applications.

Язык: Английский

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