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How doping configuration affects electron transport in monolayer zigzag graphene nanoribbon
摘要： The electrical conductance of hybrid monolayer graphene/h-BN ribbon with zigzag edges is numerically investigated using density functional theory. Our findings reveal that transmission of graphene/h-BN hybrid structure is sensitive to the arrangement of its component. The result also shows that replacing carbon atoms with boron and nitrogen totally reduces the transmission. Three different arrangement of BN domains have been investigated: replacing carbon atoms with boron and nitrogen in the transport direction, perpendicular to the transport direction and diagonal direction. We find that combination of many factors such as edge effect, additional charge carrier, interface of BN and carbon domains can alter transmission significantly.
关键词： Density functional theory,Doping configuration,Graphene/h-BN hybrid,Electronic transport
更新于2025-09-23 15:23:52
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Transport properties of doped zigzag graphene nanoribbons
摘要： Numerous studies on materials have driven the development of modern nanoelectronic devices. And research also shown that the integrated circuits have entered the era of the nanoelectronic scales from the scale of microelectronics. But the limitations of copper as a traditional connection, such as the resistivity increases a lot, further causing a lot of heat in the interconnect, have been highlighted. Therefore, we need new materials as the substitution of copper. The metallic properties exhibited by the zigzag graphene nanoribbons (ZGNRs) can be controlled by the edge states, doping and different widths of the nanoribbons. In this paper, we applied simulation to dope copper atom chains on ZGNRs. We found an energetic phenomenon that after doping the nanoribbons conductivity have increased significantly than the original. In addition, the transmission channels are mainly concentrated near the doping position, and the width used for transmission is greatly reduced after doping. It is expected to be used as an inter-connect application in nano-integrated circuits in the future.
关键词： Density functional theory,Interconnect,Electronic transport property,Non-equilibrium Green's function,Zigzag graphene nanoribbons,Doping
更新于2025-09-23 15:23:52
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Nonradiative decay and absorption rates of quantum emitters embedded in metallic systems: Microscopic description and their determination from electronic transport
摘要： We investigate nonradiative decay and absorption rates of two-level quantum emitters embedded in a metal at low temperatures. We obtain the expressions for both nonradiative transition rates and identify a unique, experimentally accessible way to obtain both nonradiative transition rates via electronic transport in the host metallic system. Our findings not only provide a microscopic description of the nonradiative channels in metals, but they also allow one to identify, determine, and differentiate them from other decay channels, which is crucial to the understanding and controlling of the light-matter interactions at the nanoscale.
关键词： nonradiative decay,metallic systems,quantum emitters,electronic transport,absorption rates
更新于2025-09-23 15:21:21
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Electronic transport induced by edge modification of graphene electrodes in single molecular device
摘要： The aim was to study the electronic transport of molecular devices constructed by salicylidene aniline molecule and graphene electrodes using the density functional theory and non-equilibrium Green’s function. The calculated results demonstrate a switching behavior in two photoisomerizations. In addition, the modification of –OH on the edge of graphene nanoribbons induces the variety of the frontier molecular orbitals and the increase of current, but the decrease of switching ratio. The modification of F on the edge of graphene nanoribbons improves the switching ratio. We explain the negative differential resistance effect found in the device by transmission spectra and the evolution of local density of states at the bias. The results indicate that different modifications on the edge of graphene nanoribbons influence the electronic transport. This method can improve the application of the device in future molecular circuits.
关键词： Electronic transport,Edge modification,Molecular switching
更新于2025-09-23 15:21:21
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Electronic transport in degenerate (100) scandium nitride thin films on magnesium oxide substrates
摘要： Scandium nitride (ScN) is a degenerate n-type semiconductor with very high carrier concentrations, low resistivity, and carrier mobilities comparable to those of transparent conducting oxides such as zinc oxide. Because of its small lattice mismatch to gallium nitride (GaN), <1%, ScN is considered a very promising material for future GaN based electronics. Impurities are the source of the degeneracy. Yet, which specific impurities are the cause has remained in contention. ScN thin films of various thicknesses were grown on magnesium oxide substrates in a (001) orientation using reactive magnetron sputtering across a range of deposition conditions. X-ray diffraction was used to verify crystal orientation. Film thicknesses ranging from 39 to 85 nm were measured using scanning electron microscopy. The electronic transport properties of the films were characterized using Hall-effect measurements at temperatures ranging from 10 to 320 K. At 10 K, the electron concentration varies from 4.4 (cid:2) 1020 to 1.5 (cid:2) 1021 cm(cid:3)3, resistivity from 2.1 (cid:2) 10(cid:3)4 to 5.0 (cid:2) 10(cid:3)5 X(cid:4)cm, and Hall mobility from 66 to 97 cm2/V(cid:4)s. Secondary ion mass spectroscopy (SIMS) was used to determine film compositions. Finally, density functional theory (DFT) was used to compute the activation energies for various point defects including nitrogen and scandium vacancies and oxygen and fluorine substituting for nitrogen. For both oxygen and fluorine substitution, the energies were negative, indicating spontaneous formation. Nevertheless, the combined results of the Hall, SIMS, and DFT strongly suggest that oxygen substitution is the primary mechanism behind the high carrier concentration in these samples.
关键词： degenerate n-type semiconductor,Hall-effect measurements,Scandium nitride,density functional theory,electronic transport properties
更新于2025-09-23 15:21:21
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Nonlinear Luttinger liquid plasmons in semiconducting single-walled carbon nanotubes
摘要： Interacting electrons confined in one dimension are generally described by the Luttinger liquid formalism, where the low-energy electronic dispersion is assumed to be linear and the resulting plasmonic excitations are non-interacting. Instead, a Luttinger liquid in one-dimensional materials with nonlinear electronic bands is expected to show strong plasmon–plasmon interactions, but an experimental demonstration of this behaviour has been lacking. Here, we combine infrared nano-imaging and electronic transport to investigate the behaviour of plasmonic excitations in semiconducting single-walled carbon nanotubes with carrier density controlled by electrostatic gating. We show that both the propagation velocity and the dynamic damping of plasmons can be tuned continuously, which is well captured by the nonlinear Luttinger liquid theory. These results contrast with the gate-independent plasmons observed in metallic nanotubes, as expected for a linear Luttinger liquid. Our findings provide an experimental demonstration of one-dimensional electron dynamics beyond the conventional linear Luttinger liquid paradigm and are important for understanding excited-state properties in one dimension.
关键词： single-walled carbon nanotubes,Nonlinear Luttinger liquid,infrared nano-imaging,plasmons,electronic transport
更新于2025-09-23 15:21:01
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Negative Differential Resistance and Hysteresis in Selfa??Assembled Nanoscale Networks with Tunable Moleculea??toa??Nanoparticle Ratios
摘要： Electronic transport is investigated through self-assembled benzenedithiol–gold nanoparticle networks with tunable molecule-to-particle ratios (1:5–50:1) deposited between planar electrodes. Two-terminal current–voltage measurements of the networks display linear behavior at low bias, which is described using a circuit model that accounts for different network morphologies, tunable via molecule-to-nanoparticle ratio, and defects. At larger biases, nonlinear negative differential resistance and hysteresis behavior are observed for different molecular concentrations, which can be attributed to a combination of ?eld-assisted tunneling and charge trapping occurring in the nanoscale networks. The directed self-assembly of benzenedithiol–metal nanoparticle molecular electronic networks is suggested for molecular integrated circuits in applications such as memory, switching, hardware security, and computing.
关键词： molecules,electronic transport,self-assembly,negative differential resistance,nanoparticles
更新于2025-09-23 15:19:57
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Nanoplatelet-Based Light-Emitting Diode and Its Use in All-Nanocrystal LiFi-like Communication
摘要： Since colloidal nanocrystals (NCs) were integrated as green and red sources for LCD displays, the next challenge for quantum dots has been their use in electrically driven light emitting diodes (LEDs). Among various colloidal nanocrystals, nanoplatelets (NPLs) appeared as promising candidates for light emitting devices because their two-dimensional shape allows a narrow luminescence spectrum, directional emission and high light extraction. To reach high quantum efficiency it is critical to grow core/shell structures. High temperature growth of the shells seems to be a better strategy than previously reported low temperature approaches to obtain bright NPLs. Here, we synthesize CdSe/CdZnS core/shell NPLs whose shell alloy content is tuned to optimize the hole injection in the LED structure. The obtained LED has exceptionally low turn-on voltage, long-term stability (>3100 h at 100 Cd.m-2), external quantum efficiency above 5% and luminance up to 35000 cd.m-2. We study the low-temperature performance of the LED and find that there is a delay of droop in terms of current density as temperature decreases. In the last part of the paper, we design a large LED (56 mm2 emitting area) and test its potential for LiFi-like communication. In such approach, the LED is not only a lightning source but also used to transmit a communication signal to a PbS quantum dot solar cell used as a broad band photodetector. Operating conditions compatible with both lighting and information transfer have been identified. This work paves the way toward an all nanocrystal-based communication setup.
关键词： efficiency droop,nanoplatelets,electronic transport,light emitting diode,nanocrystal-based communication
更新于2025-09-23 15:19:57
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Optimized Operation of Quantum-Dot Intermediate-Band Solar Cells Deduced from Electronic Transport Modeling
摘要： Study of the physics of quantum electronic transport has not tackled the problems raised by quantum-dot intermediate-band solar cells. Our study shows that this physics imposes design rules for the intersubband transition. We develop an analytical model that correctly treats, from a quantum point of view, the trade-off between the absorption, the recombination, and the electronic transport occurring in this transition. Our results clearly indicate that it is essential to control the transit rate between the excited state of the quantum dot and the embedding semiconductor. For that, we propose assuming the dot in a tunnel shell whose main characteristics can be obtained by a simple analytical formula. Moreover, we show that in a realistic case, the energy transition needs to be larger than only 0.27 eV to obtain a quasi-Fermi-level-splitting. This quite small value designates the quantum-dot solar cell as a serious candidate to be an efficient intermediate-band solar cell. This work gives a framework to design efficient intersubband transitions and opens new opportunities for quantum-dot intermediate-band solar cells.
关键词： quantum-dot,intersubband transition,electronic transport modeling,intermediate-band solar cells,quasi-Fermi-level-splitting
更新于2025-09-23 15:19:57
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Electronic transport through defective semiconducting carbon nanotubes
摘要： We investigate the electronic transport properties of semiconducting (m, n) carbon nanotubes (CNTs) on the mesoscopic length scale with arbitrarily distributed realistic defects. The study is done by performing quantum transport calculations based on recursive Green’s function techniques and an underlying density-functional-based tight-binding model for the description of the electronic structure. Zigzag CNTs as well as chiral CNTs of different diameter are considered. Different defects are exemplarily represented by monovacancies and divacancies. We show the energy-dependent transmission and the temperature-dependent conductance as a function of the number of defects. In the limit of many defetcs, the transport is described by strong localization. Corresponding localization lengths are calculated (energy dependent and temperature dependent) and systematically compared for a large number of CNTs. It is shown, that a distinction by (m ? n)mod 3 has to be drawn in order to classify CNTs with different bandgaps. Besides this, the localization length for a given defect probability per unit cell depends linearly on the CNT diameter, but not on the CNT chirality. Finally, elastic mean free paths in the diffusive regime are computed for the limit of few defects, yielding qualitatively same statements.
关键词： defect,electronic transport,density-functional-based tight binding (DFTB),Carbon nanotube (CNT),recursive Green?s function formalism (RGF),strong localization,elastic mean free path
更新于2025-09-19 17:15:36