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In the spirit of quantum drift-diffusion formalism, we propose a core compact model for low-effective mass channel common double-gate MOSFET. In contrast to the existing models, carriers in each subband are treated to be in locally thermal equilibrium within that subband, but not with the carriers in a different subband. We observe quasi-linear relationship between energy eigenvalue, quasi-Fermi level, and carrier density in each subband and exploit it to obtain closed-form expressions for drain current and terminal charges. Proposed model, which is free from any unphysical model parameter or interpolating function, captures the essential device physics (strong transverse confinement, wave function penetration, multisubband occupancy, bias-dependent diffusivity, and Fermi-Dirac distribution of the carriers) while preserving the mathematical simplicity of industry standard Silicon MOSFET models. Drain current, conductance, and capacitances calculated from the proposed model are found to be in good agreement with numerical device simulation for awide range of channel thickness, effective mass, oxide thickness asymmetry, and bias voltages. [ABSTRACT FROM AUTHOR]

Ballistic transport in monolayer Germanane MOSFETs is investigated for high-performance (HP) applications. Characteristics of both n- and p-type transistors having channel lengths of 7, 5, and 3 nm are studied and compared against the International Technology Roadmap for Semiconductor (ITRS) target of 2028. Our simulation approach is based on a self-consistent quantum ballistic transport model within the framework of the nonequilibrium Green's function formalism and relies on a single-band and a two-band k · p Hamiltonian for n- and p-type channels, respectively. We found that, even for a gate length scaled down to 3 nm, the ON current (ION) in n- and p-MOSFETs for a fixed OFF current IOFF = 100 nA/µm is as high as ~890 and 700 µA/µm, respectively. For longer channel lengths, the p-MOSFET can outperform the n-MOSFET in terms of ION requirements, as the direct source-to-drain tunneling gets suppressed. Other performance metrics, including gate capacitance, intrinsic switching delay, and switching energy, have also been calculated and found to be comparable to the ITRS 2028 HP technology requirements. [ABSTRACT FROM AUTHOR]

Symmetry of the source–channel and drain–channel junction is a unique property of a metal-oxide-semiconductor field effect transistor (MOSFET), which needs to be preserved while realizing sub-decananometer channel length devices using advanced technology. Employing experimental-findings-driven atomistic modeling techniques, we demonstrate that such symmetry might not be preserved in an atomically thin phase-engineered MoS2-based MOSFET. It originates from the two distinct atomic patterns at phase boundaries ( $\beta $ and $\beta $ *) when the semiconducting phase (channel) is sandwiched between the two metallic phases (source and drain). We develop a geometrically optimized atomic model of two independent heterophase structures comprising $\beta $ and $\beta $ * interfaces and study their electrical characteristics using density functional theory-nonequilibriumGreen’s function formalism. We further study the effect of semiconductor doping on the transmission of those planar devices and show that irrespective of the doping concentration, these heterophase structures exhibit asymmetric barrier heights. Our findings could be useful for designing integrated circuits using such advanced transistors. [ABSTRACT FROM PUBLISHER]

Formulation of accurate yet computationally efficient surface potential equation (SPE) is the fundamental step toward developing compact models for low effective mass channel quantum well MOSFETs. In this paper, we propose a new SPE for such devices considering multisubband electron occupancy and oxide thickness asymmetry. Unlike the previous attempts, here, we adopt purely physical modeling approaches (such as without mixing the solutions from finite and infinite potential wells or using any empirical model parameter), while preserving the mathematical complexity almost at the same level. Gate capacitances calculated from the proposed SPE are shown to be in good agreement with numerical device simulation for wide range of channel thickness, effective mass, oxide thickness asymmetry, and bias voltages. [ABSTRACT FROM AUTHOR]

We report a first principles study of the electronic properties for a contact formed between Nb-doped monolayer MoS2 and gold for different doping concentrations. We first focus on the shift of energy levels in band structure and the density of states with respect to the Fermi level for a geometrically optimized 5\times 5 MoS2 supercell for both pristine and Nb-doped structures. The doping is achieved by substituting Mo atoms with Nb atoms at random positions. It is observed that for an experimentally reported sheet hole doping concentration of ( \rho _{2D} ) 1.8\times 10^{14} cm ^-2 , the pristine MoS2 converts to degenerate p-type semiconductor. Next, we interface this supercell with six layers of \langle 111\rangle cleaved surface of gold to investigate the contact nature of MoS2–Au system. By careful examination of projected band structure, projected density of states, effective potential and charge density difference, we demonstrate that the Schottky barrier nature observed for pure MoS2–Au contact can be converted from n-type to p-type by efficient Nb doping. [ABSTRACT FROM PUBLISHER]

We present a computational study on the impact of line defects on the electronic properties of monolayer MoS 2. Four different kinds of line defects with Mo and S as the bridging atoms, consistent with recent theoretical and experimental observations, are considered herein. We employ the density functional tight-binding (DFTB) method with a Slater–Koster-type DFTB-CP2K basis set for evaluating the material properties of perfect and the various defective MoS 2 sheets. The transmission spectra are computed with a DFTB-non-equilibrium Green’s function formalism. We also perform a detailed analysis of the carrier transmission pathways under a small bias and investigate the phase of the transmission eigenstates of the defective MoS 2 sheets. Our simulations show a two to four fold decrease in carrier conductance of MoS2 sheets in the presence of line defects as compared to that for the perfect sheet. [ABSTRACT FROM PUBLISHER]

We present a closed-form continuous model for the electrical conductivity of a single layer graphene (SLG) sheet in the presence of short-range impurities, long-range screened impurities, and acoustic phonons. The validity of the model extends from very low doping levels (chemical potential close to the Dirac cone vertex) to very high doping levels. We demonstrate complete functional relations of the chemical potential, polarization function, and conductivity with respect to both doping level and temperature ( \(T\) ), which were otherwise developed for SLG sheet only in the very low and very high doping levels. The advantage of the continuous conductivity model reported in this paper lies in its simple form which depends only on three adjustable parameters: the short-range impurity density, the long-range screened impurity density, and temperature \(T\) . The proposed theoretical model was successfully used to correlate various experiments in the midtemperature and moderate density regimes. [ABSTRACT FROM AUTHOR]

Existing compact models for common double-gate (CDG) MOSFETs are based on the fundamental assumption of having symmetric gate oxide thickness. In this paper, we demonstrate that using the unique quasi-linear relationship between the surface potentials, it is possible to develop compact model for CDG-MOSFETs without such approximation while preserving the mathematical complexity at the same level of the existing models. In the proposed model, the surface potential relationship is used to include the drain-induced barrier lowering, channel length modulation, velocity saturation, and quantum mechanical effect in the long-channel model and good agreement is observed with the technology computer aided design simulation results. [ABSTRACT FROM AUTHOR]

We investigate the electronic properties of Germanane and analyze its importance as 2-D channel material in switching devices. Considering two types of morphologies, namely, chair and boat, we study the real band structure, the effective mass variation, and the complex band structure of unstrained Germanane by density-functional theory. The chair morphology turns out to be a more effective channel material for switching devices than the boat morphology. Furthermore, we study the effect of elastic strain, van der Waals force, and vertical electric field on these band structure properties. Due to its very low effective mass with relatively high-energy bandgap, in comparison with the other 2-D materials, Germanane appears to provide superior performance in switching device applications. [ABSTRACT FROM AUTHOR]

We address a physics-based solution of joule heating phenomenon in a single-layer graphene (SLG) sheet under the presence of Thomson effect. We demonstrate that the temperature in an isotopically pure (containing only C^12) SLG sheet attains its saturation level quicker than when doped with its isotopes (C^13). From the solution of the joule heating equation, we find that the thermal time constant of the SLG sheet is in the order of tenths of a nanosecond for SLG dimensions of a few micrometers. These results have been formulated using the electron interactions with the inplane and flexural phonons to demonstrate a field-dependent Landauer transmission coefficient. We further develop an analytical model of the SLG specific heat using the quadratic (out of plane) phonon band structure over the room temperature. Additionally, we show that a cooling effect in the SLG sheet can be substantially enhanced with the addition of C^13. The methodologies as discussed in this paper can be put forward to analyze the graphene heat spreader theory. [ABSTRACT FROM AUTHOR]

We present a computational study on the impact of tensile/compressive uniaxial (\varepsilonxx) and biaxial (\varepsilonxx=\varepsilon{\rm yy}) strain on monolayer MoS2, n-, and p-MOSFETs. The material properties like band structure, carrier effective mass, and the multiband Hamiltonian of the channel are evaluated using the density functional theory. Using these parameters, self-consistent Poisson–Schrödinger solution under the nonequilibrium Green's function formalism is carried out to simulate the MOS device characteristics. 1.75% uniaxial tensile strain is found to provide a minor (6%) ON current improvement for the n-MOSFET, whereas same amount of biaxial tensile strain is found to considerably improve the p-MOSFET ON currents by 2–3 times. Compressive strain, however, degrades both n-MOS and p-MOS devices performance. It is also observed that the improvement in p-MOSFET can be attained only when the channel material becomes indirect gap in nature. We further study the performance degradation in the quasi-ballistic long-channel regime using a projected current method. [ABSTRACT FROM AUTHOR]

In this paper, we address a physics-based analytical model of electric-field-dependent electron mobility (\mu) in a single-layer graphene sheet using the formulation of Landauer and Mc Kelvey's carrier flux approach under finite temperature and quasi-ballistic regime. The energy-dependent, near-elastic scattering rate of in-plane and out-of-plane (flexural) phonons with the electrons are considered to estimate \mu over a wide range of temperature. We also demonstrate the variation of \mu with carrier concentration as well as the longitudinal electric field. We find that at high electric field (>10^6~Vm^-1), the mobility falls sharply, exhibiting the scattering between the electrons and flexural phonons. We also note here that under quasi-ballistic transport, the mobility tends to a constant value at low temperature, rather than in between T^-2 and T^-1 in strongly diffusive regime. Our analytical results agree well with the available experimental data, while the methodologies are put forward to estimate the other carrier-transmission-dependent transport properties. [ABSTRACT FROM AUTHOR]

With the unique quasi-linear relationship between the surface potentials along the channel, recently we have proposed a quasi-static terminal charge model for common double-gate MOSFETs, which might have asymmetric gate oxide thickness. In this brief, we extend this concept to develop the nonquasi-static (NQS) charge model for the same by solving the governing continuity equations. The proposed NQS model shows good agreement against TCAD simulations and appears to be useful for efficient circuit simulation. [ABSTRACT FROM PUBLISHER]

We investigate the thermoelectric (TE) figure-of-merit of a single-layer graphene (SLG) sheet by a physics-based analytical technique. We first develop analytical models of electrical and thermal resistances and the Seebeck coefficient of SLG by considering electron interactions with the in-plane and flexural phonons. Using those models, we show that both the figure-of-merit and the TE efficiency can be substantially increased with the addition of isotope doping as it significantly reduces the phonon-dominated thermal conductivity. In addition, we report that the TE open circuit output voltage and output power depends weakly on the SLG sheet dimensions and sheet concentration in the strongly diffusive regime. Proposed models agree well with the available experimental data and demonstrate the immense potential of graphene for waste-heat recovery application. [ABSTRACT FROM PUBLISHER]

We investigate the direct band-to-band tunneling (BTBT) in a reverse biased molybdenum disulfide (\MoS2) nanoribbon p-n junction by analyzing the complex band structure obtained from semiempirical extended Hückel method under relaxed and strained conditions. It is demonstrated that the direct BTBT is improbable in relaxed monolayer nanoribbon; however, with the application of certain uniaxial tensile strain, the material becomes favorable for it. On the other hand, the relaxed bilayer nanoribbon is suitable for direct BTBT but becomes unfavorable when the applied uniaxial tensile or compressive strain goes beyond a certain limit. Considering the Wentzel–Kramers–Brillouin approximation, we evaluate the tunneling probability to estimate the tunneling current for a small applied reverse bias. Reasonably high tunneling current in the \MoS2 nanoribbons shows that it can take advantage over graphene nanoribbon in future tunnel field-effect transistor applications. [ABSTRACT FROM AUTHOR]

In this brief, we present a physics-based solution for the temperature-dependent electrical resistance of a suspended metallic single-layer graphene (SLG) sheet under Joule self-heating. The effect of in-plane and flexural phonons on the electron scattering rates for a doped SLG layer has been considered, which particularly demonstrates the variation of the electrical resistance with increasing temperature at different current levels using the solution of the self-heating equation. The present solution agrees well with the available experimental data done with back-gate electrostatic method over a wide range of temperatures. [ABSTRACT FROM AUTHOR]

We propose a new set of input voltage equations (IVEs) for independent double-gate MOSFET by solving the governing bipolar Poisson equation (PE) rigorously. The proposed IVEs, which involve the Legendre's incomplete elliptic integral of the first kind and Jacobian elliptic functions and are valid from accumulation to inversion regimes, are shown to have good agreement with the numerical solution of the same PE for all bias conditions. [ABSTRACT FROM AUTHOR]

Charge linearization techniques have been used over the years in advanced compact models for bulk and double-gate MOSFETs in order to approximate the position along the channel as a quadratic function of the surface potential (or inversion charge densities) so that the terminal charges can be expressed as a compact closed-form function of source and drain end surface potentials (or inversion charge densities). In this paper, in case of the independent double-gate MOSFETs, we show that the same technique could be used to model the terminal charges quite accurately only when the 1-D Poisson solution along the channel is fully hyperbolic in nature or the effective gate voltages are same. However, for other bias conditions, it leads to significant error in terminal charge computation. We further demonstrate that the amount of nonlinearity that prevails between the surface potentials along the channel actually dictates if the conventional charge linearization technique could be applied for a particular bias condition or not. Taking into account this nonlinearity, we propose a compact charge model, which is based on a novel piecewise linearization technique and shows excellent agreement with numerical and Technology Computer-Aided Design (TCAD) simulations for all bias conditions and also preserves the source/drain symmetry which is essential for Radio Frequency (RF) circuit design. The model is implemented in a professional circuit simulator through Verilog-A, and simulation examples for different circuits verify good model convergence. [ABSTRACT FROM PUBLISHER]

In this paper, we propose a physics-based simplified analytical model of the energy band gap and electron effective mass in a relaxed and strained rectangular [100] silicon nanowires (SiNWs). Our proposed formulation is based on the effective mass approximation for the nondegenerate two-band model and 4 \times 4 Lüttinger Hamiltonian for energy dispersion relation of conduction band electrons and the valence band heavy and light holes, respectively. Using this, we demonstrate the effect of the uniaxial strain applied along [100]-direction and a biaxial strain, which is assumed to be decomposed from a hydrostatic deformation along [001] followed by a uniaxial one along the [100]-direction, respectively, on both the band gap and the transport and subband electron effective masses in SiNW. Our analytical model is in good agreement with the extracted data using the extended-Hückel-method-based numerical simulations over a wide range of device dimensions and applied strain. [ABSTRACT FROM PUBLISHER]

Surface-potential-based compact charge models for symmetric double-gate metal–oxide–semiconductor field-effect transistors (SDG-MOSFETs) are based on the fundamental assumption of having equal oxide thicknesses for both gates. However, for practical devices, there will always be some amount of asymmetry between the gate oxide thicknesses due to process variations and uncertainties, which can affect device performance significantly. In this paper, we propose a simple surface-potential-based charge model, which is applicable for tied double-gate MOSFETs having same gate work function but could have any difference in gate oxide thickness. The proposed model utilizes the unique so-far-unexplored quasi-linear relationship between the surface potentials along the channel. In this model, the terminal charges could be computed by basic arithmetic operations from the surface potentials and applied biases, and thus, it could be implemented in any circuit simulator very easily and extendable to short-channel devices. We also propose a simple physics-based perturbation technique by which the surface potentials of an asymmetric device could be obtained just by solving the input voltage equation of SDG devices for small asymmetry cases. The proposed model, which shows excellent agreement with numerical and TCAD simulations, is implemented in a professional circuit simulator through the Verilog-A interface and demonstrated for a 101-stage ring oscillator simulation. It is also shown that the proposed model preserves the source/drain symmetry, which is essential for RF circuit design. [ABSTRACT FROM AUTHOR]

A robust numerical solution of the input voltage equations (IVEs) for the independent-double-gate metal–oxide–semiconductor field-effect transistor requires root bracketing methods (RBMs) instead of the commonly used Newton–Raphson (NR) technique due to the presence of nonremovable discontinuity and singularity. In this brief, we do an exhaustive study of the different RBMs available in the literature and propose a single derivative-free RBM that could be applied to both trigonometric and hyperbolic IVEs and offers faster convergence than the earlier proposed hybrid NR–Ridders algorithm. We also propose some adjustments to the solution space for the trigonometric IVE that leads to a further reduction of the computation time. The improvement of computational efficiency is demonstrated to be about 60% for trigonometric IVE and about 15% for hyperbolic IVE, by implementing the proposed algorithm in a commercial circuit simulator through the Verilog-A interface and simulating a variety of circuit blocks such as ring oscillator, ripple adder, and twisted ring counter. [ABSTRACT FROM AUTHOR]

In this paper, we address a closed-form analytical solution of the Joule-heating equation for metallic single-walled carbon nanotubes (SWCNTs). Temperature-dependent thermal conductivity \kappa has been considered on the basis of second-order three-phonon Umklapp, mass difference, and boundary scattering phenomena. It is found that \kappa, in case of pure SWCNT, leads to a low rising in the temperature profile along the via length. However, in an impure SWCNT, \kappa reduces due to the presence of mass difference scattering, which significantly elevates the temperature. With an increase in impurity, there is a significant shift of the hot spot location toward the higher temperature end point contact. Our analytical model, as presented in this study, agrees well with the numerical solution and can be treated as a method for obtaining an accurate analysis of the temperature profile along the CNT-based interconnects. [ABSTRACT FROM PUBLISHER]

Although the recently proposed single-implicit-equation-based input voltage equations (IVEs) for the independent double-gate (IDG) MOSFET promise faster computation time than the earlier proposed coupled-equations-based IVEs, it is not clear how those equations could be solved inside a circuit simulator as the conventional Newton–Raphson (NR)-based root finding method will not always converge due to the presence of discontinuity at the G-zero point (GZP) and nonremovable singularities in the trigonometric IVE. In this paper, we propose a unique algorithm to solve those IVEs, which combines the Ridders algorithm with the NR-based technique in order to provide assured convergence for any bias conditions. Studying the IDG MOSFET operation carefully, we apply an optimized initial guess to the NR component and a minimized solution space to the Ridders component in order to achieve rapid convergence, which is very important for circuit simulation. To reduce the computation budget further, we propose a new closed-form solution of the IVEs in the near vicinity of the GZP. The proposed algorithm is tested with different device parameters in the extended range of bias conditions and successfully implemented in a commercial circuit simulator through its Verilog-A interface. [ABSTRACT FROM PUBLISHER]

We present a simplified theory of carrier backscattering coefficient in a twofold degenerate asymmetric bilayer graphene nanoribbon (BGN) under the application of a low static electric field. We show that for a highly asymmetric BGN \left(\triangle =\gamma \right), the density of states in the lower subband increases more that of the upper, in which \triangle and \gamma are the gap and the interlayer coupling constant, respectively. We also demonstrate that under the acoustic phonon scattering regime, the formation of two distinct sets of energy subbands signatures a quantized transmission coefficient as a function of ribbon width and provides an extremely low carrier reflection coefficient for a better Landauer conductance even at room temperature. The well-known result for the ballistic condition has been obtained as a special case of the present analysis under certain limiting conditions which forms an indirect validation of our theoretical formalism. [ABSTRACT FROM PUBLISHER]

In this paper, we show the limitations of the traditional charge linearization techniques for modeling terminal charges of the independent double-gate metal–oxide–semiconductor field-effect transistors. Based on our recent computationally efficient Poisson solution for independent double gate transistors, we propose a new charge linearization technique to model the terminal charges and transcapacitances. We report two different types of quasistatic large-signal models for the long-channel device. In the first type, the terminal charges are expressed as closed-form functions of the source- and drain-end inversion charge densities and found to be accurate when the potential distribution at source end of the channel is hyperbolic in nature. The second type, which is found to be accurate in all regimes of operations, is based on the quadratic spline collocation technique and requires the input voltage equation to be solved two more times, apart from the source and drain ends. [ABSTRACT FROM AUTHOR]

Previous techniques used for solving the 1-D Poisson equation (PE) rigorously for long-channel asymmetric and independent double-gate (IDG) transistors result in potential models that involve multiple intercoupled implicit equations. As these equations need to be solved self-consistently, such potential models are clearly inefficient for compact modeling. This paper reports a different rigorous technique for solving the same PE by which one can obtain the potential profile of a generalized IDG transistor that involves a single implicit equation. The proposed Poisson solution is shown to be computationallymore efficient for circuit simulation than the previous solutions. [ABSTRACT FROM AUTHOR]

The current-biased single electron transistor (SET) (CBS) is an integral part of almost all hybrid CMOS SET circuits. In this paper, for the first time, the effects of energy quantization on the performance of CBS-based circuits are studied through analytical modeling and Monte Carlo simulations. It is demonstrated that energy quantization has no impact on the gain of CBS characteristics, although it changes the output voltage levels and oscillation periodicity. The effects of energy quantization further studied for two circuits: negative differential resistance (NDR) and neuron cell, which use the CBS. A new model the conductance of NDR characteristics is also formulated that includes the energy quantization term. [ABSTRACT FROM AUTHOR]

A new physically based classical continuous potential distribution model, particularly considering the channel center, is proposed for a short-channel undoped body symmetrical double-gate transistor. It involves a novel technique for solving the 2-D nonlinear Poisson's equation in a rectangular coordinate system, which makes the model valid from weak to strong inversion regimes and from the channel center to the surface. We demonstrated, using the proposed model, that the channel potential versus gate voltage characteristics for the devices having equal channel lengths but different thicknesses pass through a single common point (termed "crossover point"). Based on the potential model, a new compact model for the subthreshold swing is formulated. It is shown that for the devices having very high short-channel effects (SCE), the effective subthreshold slope factor is mainly dictated by the potential close to the channel center rather than the surface. SCEs and drain-induced barrier lowering are also assessed using the proposed model and validated against a professional numerical device simulator. [ABSTRACT FROM AUTHOR]

A new physically based classical model for the potential distribution of an undoped body cylindrical gate-all-around nanowire transistor is proposed. The model is based on the analytical solution of 2-D Poisson's equation in a cylindrical coordinate system and is valid for both 1) weak and strong inversion regimes, 2) long and short-channel transistors, and 3) body surfaces and centers. Using the proposed model, for the first time, it is demonstrated that the body potential versus gate voltage characteristics for the devices having equal channel lengths but different body radii pass through a single common point (termed a "crossover point"). It is found that, at this crossover point, there is no potential drop ("pseudo fiatband condition") along the radial direction. Using the concept of crossover point, the effect of body radius on the threshold voltage of undoped body multigate transistors is explained. Based on the proposed body potential model, a new compact model for the subthreshold swing is formulated. It is shown that for the devices having very high short-channel effects, the effective subthreshold slope factor is mainly dictated by the potential at the body center rather than that at the surface. All the models are validated against a professional numerical device simulator. [ABSTRACT FROM AUTHOR]

A compact model for noise margin (NM) of single-electron transistor (SET) logic is developed, which is a function of device capacitances and background charge (ζ). Noise margin is, then, used as a metric to evaluate the robustness of SET logic against background charge, temperature, and variation of SET gate and tunnel junction capacitances (CG and CT). It is shown that choosing α = CT/CG = 1/3 maximizes the NM. An estimate of the maximum tolerable ζ is shown to be equal to ±0.03e. Finally, the effect of mismatch in device parameters on the NM is studied through exhaustive simulations, which indicates that α ∊ [0.3, 0.4] provides maximum robustness. It is also observed that mismatch can have a significant impact on static power dissipation. [ABSTRACT FROM AUTHOR]

A physicaIly based compact analytical single electron transistor (SET) model is proposed for hybrid CMOS-SET analog circuit simulation. The modeling approach is based on the "orthodox theory" of single electron tunneling, and valid for single or multi gate, symmetric or asymmetric devices and can also explain the background charge effect. The model parameters are physical device parameters and an associated parameter extraction procedure is reported. The device characteristics produced by the proposed model are verified with Monte Carlo simulation for large range of drain to source voltages (|VDS| ⩽ 3e/CΣ) and temperatures [T ⩽ e2|(10κBCΣ )| and good agreements are observed. The proposed model is implemented in a commercial circuit simulator in order to develop a computer-aided design framework for CMOS-SET hybrid IC designs. A series of SPICE simulations are successfully carried out for different CMOS-SET hybrid circuits in order to reproduce their experimental/Monte Carlo simulated characteristics. [ABSTRACT FROM AUTHOR]

We investigate the gate-controlled direct band-to-band tunneling (BTBT) current in a graphene–boron nitride (G-BN) heterobilayer channel-based tunnel field effect transistor. We first study the imaginary band structure of hexagonal and Bernal-stacked heterobilayers by density functional theory, which is then used to evaluate the gate-controlled current under the Wentzel–Kramers–Brillouin approximation. It is shown that the direct BTBT is probable for a certain interlayer spacing of the G-BN which depends on the stacking orders. [ABSTRACT FROM PUBLISHER]

In this letter, a closed-form analytical model for temperature-dependent longitudinal diffusive lattice thermal conductivity (\kappa) of a metallic single-walled carbon nanotube (SWCNT) has been addressed. Based on the Debye theory, the second-order three-phonon Umklapp, mass difference (MD), and boundary scatterings have been incorporated to formulate \kappa in both low- and high-temperature regimes. It is proposed that \kappa at low temperature (T) follows the T^3 law and is independent of the second-order three-phonon Umklapp and MD scatterings. The form factor due to MD scattering also plays a key role in the significant variation of \kappa in addition to the SWCNT length. The present diameter-independent model of \kappa agrees well with the available experimental data on suspended intrinsic metallic SWCNTs over a wide range of temperature and can be carried forward for electrothermal analyses of CNT-based interconnects. [ABSTRACT FROM AUTHOR]

A correction to the article "Piecewise Linearization Technique for Compact Charge Modeling of Independent DG MOSFET" that was published in the November 26, 2012 issue is presented.