Showing papers on "Effective mass (solid-state physics) published in 2006"
TL;DR: In this paper, the structural, electronic, and optical properties of Ga2O3 in its ambient, monoclinic and high-pressure, hexagonal phases in the framework of all-electron density functional theory were investigated.
Abstract: We report the results of a comprehensive study on the structural, electronic, and optical properties of Ga2O3 in its ambient, monoclinic and high-pressure, hexagonal phases in the framework of all-electron density functional theory. In both phases, the conduction band minimum is at the zone center while the valance band maximum is rather flat in the k space. The calculated electron effective mass me /m0 comes out to be 0.342 and 0.276 for -Ga2O3 and -Ga2O3, respectively. The dynamic dielectric function, reflectance, and energy-loss function for both phases are reported for a wide energy range of 0 – 50 eV. The subtle differences in electronic and optical properties can be attributed to the higher symmetry, coordination number of Ga atoms, and packing density in -Ga2O3 relative to that in -Ga2O3.
506 citations
TL;DR: In this paper, the first direct observation of relativistic Dirac fermions with linear dispersion near the Brillouin zone (BZ) corner H was reported.
Abstract: Originating from relativistic quantum field theory, Dirac fermions have been invoked recently to explain various peculiar phenomena in condensed-matter physics, including the novel quantum Hall effect in graphene1,2, the magnetic-field-driven metal–insulator-like transition in graphite3,4, superfluidity in 3He (ref. 5) and the exotic pseudogap phase of high-temperature superconductors6,7. Despite their proposed key role in those systems, direct experimental evidence of Dirac fermions has been limited. Here, we report the first direct observation of relativistic Dirac fermions with linear dispersion near the Brillouin zone (BZ) corner H, which coexist with quasiparticles that have a parabolic dispersion near another BZ corner K. In addition, we also report a large electron pocket that we attribute to defect-induced localized states. Thus, graphite presents a system in which massless Dirac fermions, quasiparticles with finite effective mass and defect states all contribute to the low-energy electronic dynamics.
405 citations
TL;DR: Scanning tunnelling spectroscopy observations of an organic monolayer film on a silver substrate reveal a completely delocalized two-dimensional band state that is characterized by a metal-like parabolic dispersion with an effective mass of m* = 0.47me, where me is the bare electron mass.
Abstract: When a current flows through a molecular material, the electrons may either hop slowly from molecule to molecule, or they may move swiftly through the material at large The latter mechanism is possible only if the electronic states involved in current flow are dispersed and allow extensive electron delocalization Scanning tunnelling microscopy experiments on an archetypal organic semiconductor (PTCDA) deposited on a silver substrate have now made extensive dispersion and electron delocalization visible for the first time in a thin molecular layer The observed dispersion is far stronger than expected for the organic material alone This suggests that strong electron mobility enhancements — as often desired for electronic applications — may be achieved by tailoring the intermolecular coupling between organic molecules and their metal substrate Thin films of molecular organic semiconductors are attracting much interest for use in electronic and optoelectronic applications The electronic properties of these materials and their interfaces are therefore worth investigating intensively1,2,3, particularly the degree of electron delocalization that can be achieved2,4 If the delocalization is appreciable, it should be accompanied by an observable electronic band dispersion But so far only limited experimental data on the intermolecular dispersion of electronic states in molecular materials is available5,6,7,8, and the mechanism(s) of electron delocalization in molecular materials are also not well understood Here we report scanning tunnelling spectroscopy observations of an organic monolayer film on a silver substrate, revealing a completely delocalized two-dimensional band state that is characterized by a metal-like parabolic dispersion with an effective mass of m* = 047me, where me is the bare electron mass This dispersion is far stronger than expected for the organic film alone7, and arises as a result of strong substrate-mediated coupling between the molecules within the monolayer
232 citations
TL;DR: The experimental study of InN and In-rich InGaN by a number of structural, optical and electrical methods is reviewed in this article, where the electron effective mass in InN is interpreted in terms of a non-parabolic conduction band caused by the k · p interaction across the narrow gap.
Abstract: The experimental study of InN and In-rich InGaN by a number of structural, optical and electrical methods is reviewed. Recent advances in thin film growth have produced single crystal epitaxial layers of InN which are similar in structural quality to GaN films made under similar conditions and which can have electron concentrations below 1 × 1018 cm−3 and mobilities exceeding 2000 cm2 (Vs)−1. Optical absorption, photoluminescence, photo-modulated reflectance and soft x-ray spectroscopy measurements were used to establish that the room temperature band gap of InN is 0.67 ± 0.05 eV. Experimental measurements of the electron effective mass in InN are presented and interpreted in terms of a non-parabolic conduction band caused by the k · p interaction across the narrow gap. Energetic particle irradiation is shown to be an effective method to control the electron concentration, n, in undoped InN. Optical studies of irradiated InN reveal a large Burstein–Moss shift of the absorption edge with increasing n. Fundamental studies of the energy levels of defects in InN and of electron transport are also reviewed. Finally, the current experimental evidence for p-type activity in Mg-doped InN is evaluated.
225 citations
TL;DR: In this article, a 3D simulation framework based on the nonequilibrium Green's function formalism was developed to handle electronic transport in nanoscale silicon devices within the effective mass and Hartree approximations.
Abstract: Based on the nonequilibrium Green’s function formalism, we have developed a three-dimensional (3D) simulation framework capable of handling electronic transport in nanoscale silicon devices within the effective mass and Hartree approximations. Using the deformation potential theory and the self-consistent Born approximation, we obtain the spatially local self-energy functions for the intravalley and intervalley phonon scattering mechanisms. To make the 3D simulation practicable, we reduce the computational complexity by using the mode space approach suitable for the device whose cross section is relatively uniform along the transport direction. We also obtain the expression for the phonon-limited low field mobility in the long channel limit from the linear response theory. As an application, we study the quantum transport of the silicon nanowire transistor whose channel length is 15nm in the ballistic limit and in the presence of the electron-phonon interactions. We can observe various effects of the elec...
191 citations
TL;DR: In this article, the energy-band gap of the Al2O3-InGaAs interface was determined to be 3.83±0.05eV by x-ray photoelectron spectroscopy.
Abstract: The valence-band offset has been determined to be 3.83±0.05eV at the atomic-layer-deposition Al2O3∕InGaAs interface by x-ray photoelectron spectroscopy. The Au–Al2O3∕InGaAs metal-oxide-semiconductor diode exhibits current-voltage characteristics dominated by Fowler-Nordheim tunneling. From the current-voltage data at forward and reverse biases, a conduction-band offset of 1.6±0.1eV at the Al2O3–InGaAs interface and an electron effective mass ∼0.28±0.04m0 of the Al2O3 layer have been extracted. Consequently, combining the valence-band offset, the conduction-band offset, and the energy-band gap of the InGaAs, the energy-band gap of the atomic-layer-deposited Al2O3 is 6.65±0.11eV.
179 citations
TL;DR: In this article, the exact exchange density functional theory was applied to the electronic structure of InN and GaN employing G0W0 calculations based on exact-exchange density-functional theory.
Abstract: The authors have studied the electronic structure of InN and GaN employing G0W0 calculations based on exact-exchange density-functional theory. For InN their approach predicts a gap of 0.7eV. Taking the Burnstein-Moss effect into account, the increase of the apparent quasiparticle gap with increasing electron concentration is in good agreement with the observed blueshift of the experimental optical absorption edge. Moreover, the concentration dependence of the effective mass, which results from the nonparabolicity of the conduction band, agrees well with recent experimental findings. Based on the quasiparticle band structure the parameter set for a 4×4k∙p Hamiltonian has been derived.
146 citations
TL;DR: In this paper, the range of the elements of the neutrino mass matrix in the charged lepton basis was studied and the phenomenological implications of single texture zeros were analyzed.
Abstract: We study the range of the elements of the neutrino mass matrix ${m}_{\ensuremath{
u}}$ in the charged lepton basis. Neutrinoless double beta decay is sensitive to the $ee$ element (the effective mass) of ${m}_{\ensuremath{
u}}$. We then analyze the phenomenological implications of single texture zeros. In particular, interesting predictions for the effective mass can be obtained, in the sense that typically only little cancellation due to the Majorana phases is expected. Some cases imply constraints on the atmospheric neutrino mixing angle.
145 citations
TL;DR: It is proved that the Fermi energy (EF) resides in a Mn-induced impurity band (IB), and the changes in the frequency dependent optical conductivity with carrier density are only consistent with EF lying in an IB.
Abstract: The band structure of a prototypical dilute magnetic semiconductor (DMS), Ga1� xMnxAs, is studied across the phase diagram via infrared and optical spectroscopy. We prove that the Fermi energy (EF) resides in a Mn-induced impurity band (IB). Specifically the changes in the frequency dependent optical conductivity [� 1� !� ] with carrier density are only consistent with EF lying in an IB. Furthermore, the large effective mass (m � ) of the carriers inferred from our analysis of � 1� !� supports this conclusion. Our findings demonstrate that the metal to insulator transition in this DMS is qualitatively different from other III-V semiconductors doped with nonmagnetic impurities. We also provide insights into the anomalous transport properties of Ga1� xMnxAs.
144 citations
TL;DR: In this article, a comprehensive quantum anisotropic transport model for holes was used to study silicon PMOS inversion layer transport under arbitrary stress, and the results showed that the hole band structure is dominated by 12 "wings", where mechanical stress, as well as the vertical field under certain stress conditions, can alter the energies of the few lowest hole subbands, changing the transport effective mass, density of states, and scattering rates, and thus affecting the mobility.
Abstract: A comprehensive quantum anisotropic transport model for holes was used to study silicon PMOS inversion layer transport under arbitrary stress. The anisotropic band structures of bulk silicon and silicon under field confinement as a twodimensional quantum gas are computed using the pseudopotential method and a six-band stress-dependent k.p Hamiltonian. Anisotropic scattering is included in the momentum-dependent scattering rate calculation. Mobility is obtained from the Kubo-Greenwood formula at low lateral field and from the fullband Monte Carlo simulation at high lateral field. Using these methods, a comprehensive study has been performed for both uniaxial and biaxial stresses. The results are compared with device bending data and piezoresistance data for uniaxial stress, and device data from strained Si channel on relaxed SiGe substrate devices for biaxial tensile stress. All comparisons show a very good agreement with simulation. It is found that the hole band structure is dominated by 12 "wings," where mechanical stress, as well as the vertical field under certain stress conditions, can alter the energies of the few lowest hole subbands, changing the transport effective mass, density-of-states, and scattering rates, and thus affecting the mobility
141 citations
TL;DR: The dynamic mass density expression, first derived by Berryman more than two decades ago, is shown to give a closer correspondence between the acoustic and electromagnetic metamaterials by allowing for negative mass densities at frequencies around resonances.
Abstract: We show through rigorous derivation and experimental support that the dynamic effective mass density of an inhomogeneous mixture, used in the prediction of wave velocities in the long wavelength limit, can differ from the static version—the volume average of the component mass densities. The physical reason for this difference is explained. The dynamic mass density expression, first derived by Berryman more than two decades ago, is shown to give a closer correspondence between the acoustic and electromagnetic metamaterials by allowing for negative mass densities at frequencies around resonances. The effective mass density of a composite is one of the most basic quantities in the study of materials. It is common sense that the effective mass density of a mixture of
TL;DR: In this article, structural, electronic, and optical properties for the cubic, tetragonal, and monoclinic crystalline phases of ZrO2, as derived from ab initio full-relativistic calculations, are presented.
Abstract: Structural, electronic, and optical properties for the cubic, tetragonal, and monoclinic crystalline phases of ZrO2, as derived from ab initio full-relativistic calculations, are presented. The electronic structure calculations were carried out by means of the all-electron full-potential linear augmented plane wave method, within the framework of the density functional theory and the local density approximation. The calculated carrier effective masses are shown to be highly anisotropic. The results obtained for the real and imaginary parts of the dielectric function, the reflectivity, and the refraction index show good agreement with the available experimental results. In order to obtain the static dielectric constant of ZrO2, we added to the electronic part the optical phonon contribution, which leads to values of ϵ1(0)≃29.5,26.2,21.9, respectively, along the xx, yy, and zz directions, for the monoclinic phase, in excellent accordance with experiment. Relativistic effects, including the spin-orbit intera...
TL;DR: In this article, the electronic structure of InN and GaN using G0W0 calculations based on exact-exchange density-functional theory was studied and a gap of 0.7 eV was predicted.
Abstract: We have studied the electronic structure of InN and GaN employing G0W0 calculations based on exact-exchange density-functional theory. For InN our approach predicts a gap of 0.7 eV. Taking the Burnstein-Moss effect into account, the increase of the apparent quasiparticle gap with increasing electron concentration is in good agreement with the observed blue shift of the experimental optical absorption edge. Moreover, the concentration dependence of the effective mass, which results from the non-parabolicity of the conduction band, agrees well with recent experimental findings. Based on the quasiparticle band structure the parameter set for a 4x4 kp Hamiltonian has been derived.
TL;DR: In this article, the authors investigated the electronic and thermodynamic properties of β-Ga2O3 in the framework of density functional theory and obtained the equilibrium structural parameters and Debye temperature through fitting of the energy surface to the equation of state.
Abstract: Electronic and thermodynamic properties of β-Ga2O3 are investigated in the framework of density functional theory. The equilibrium structural parameters and Debye temperature are obtained through fitting of the energy surface to the equation of state. Analysis of the band structure shows the valence band maximum to be degenerate at Γ and M, whereas the conduction band minimum is predicted to be at Γ. The valence band is almost flat, indicating a rather large effective mass for holes, whereas the calculated electron effective mass comes out to be about 0.12, expressed in units of the free electron mass.
TL;DR: In this article, two-dimensional electrons in AlAs quantum wells occupy multiple conduction-band minima at the X-points of the Brillouin zone, and these valleys have large effective mass and g-factor compared to the standard GaAs electrons.
Abstract: Two-dimensional electrons in AlAs quantum wells occupy multiple conduction-band minima at the X-points of the Brillouin zone. These valleys have large effective mass and g -factor compared to the standard GaAs electrons, and are also highly anisotropic. With proper choice of well width and by applying symmetry-breaking strain in the plane, one can control the occupation of different valleys thus rendering a system with tuneable effective mass, g -factor, Fermi contour anisotropy, and valley degeneracy. Here we review some of the rich physics that this system has allowed us to explore. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
TL;DR: In this article, the structural and electrical properties of metal-oxide-semiconductor capacitors incorporating HfO2 dielectrics were investigated, and the barrier height at the Al∕HfO 2 interface was determined to be about 0.94eV.
Abstract: Metal-oxide-semiconductor capacitors incorporating HfO2 dielectrics were fabricated and investigated. In this work, the structural and electrical characterizations were performed at the interfaces of HfO2∕Si and Al∕HfO2, respectively. The physical analyses reveal that an interfacial layer of Hf-silicate between 700°C-annealed HfO2 and Si was formed. The dominant conduction mechanisms of the Al∕HfO2∕p-Si structure are the Schottky emission at high temperatures (≳465K) and low electric fields (≲2.2MV∕cm) and the Fowler-Nordheim tunneling at low temperature (77K) and high electric fields (≳2.6MV∕cm), respectively. The electron effective mass in HfO2 and the barrier height at the Al∕HfO2 interface are evaluated using both the intercept of the Schottky plot and the slope of the Fowler-Nordheim plot. Therefore, the barrier height at the Al∕HfO2 interface was determined to be about 0.94eV. The electron effective masses in HfO2 are 0.4m0 and 0.09m0 for the effective oxide thickness (EOT)=6nm and EOT=3.15nm, respectively.
TL;DR: In this paper, first-principles density-functional-theory calculations with different approximations for zinc monochalcogenides with zinc-blende-and wurtzite-type structures are studied.
Abstract: Electronic structure and band characteristics for zinc monochalcogenides with zinc-blende- and wurtzite-type structures are studied by first-principles density-functional-theory calculations with different approximations. It is shown that the local-density approximation underestimates the band gap and energy splitting between the states at the top of the valence band, misplaces the energy levels of the Zn-3d states, and overestimates the crystal-field-splitting energy. The spin-orbit-coupling energy is found to be overestimated for both variants of ZnO, underestimated for ZnS with wurtzite-type structure, and more or less correct for ZnSe and ZnTe with zinc-blende-type structure. The order of the states at the top of the valence band is found to be anomalous for both variants of ZnO, but is normal for the other zinc monochalcogenides considered. It is shown that the Zn-3d electrons and their interference with the O-2p electrons are responsible for the anomalous order. The effective masses of the electrons...
TL;DR: In this article, the ground state properties and structural phase transformation of beryllium chalcogenides (BeS, BeSe, and BeTe) have been investigated using first principle full potential-linearized augmented plane wave method (FP-LAPW) within density functional theory.
TL;DR: In this article, it was shown that the actual band-gap energy of Zn3N2 polycrystalline films with n+-type conductivity is 1.06eV and that the significant blue shift of the optical band gap with increasing carrier concentration obeys the relation Eopt=1.06+1.30×10−14ne2∕3.
Abstract: Zn3N2 polycrystalline films with n+-type conductivity have been grown by metalorganic chemical vapor deposition and rf-molecular beam epitaxy with carrier concentration in the range between 1019 and ∼1020cm−3. Oxygen contamination without an intentional doping was found to be a cause of high electron concentration, leading to a larger band-gap energy due to Burstein-Moss shift. The significant blue shift of the optical band gap Eopt with increasing carrier concentration ne obeys the relation Eopt=1.06+1.30×10−14ne2∕3. This evaluation enables the conclusion that the actual band-gap energy of Zn3N2 is 1.06eV. Electron effective mass m* for Zn3N2 has been deduced from Fourier transform infrared reflectivity measurements to be (0.29±0.05)mo.
TL;DR: In this paper, a high resolution angle resolved photoemission spectroscopy (ARPES) study of the electronic properties of graphite was presented, which showed that the nature of the low energy excitations in graphite is particularly sensitive to interlayer coupling as well as lattice disorder.
TL;DR: From current-voltage measurements, it appears likely that, for both types of junctions, electrons are the main carrier type, although holes may contribute significantly to the transport in the p-GaAs system.
Abstract: A series of p- and n-GaAs−S−CnH2n+1 || Hg junctions are prepared, and the electronic transport through them is measured. From current−voltage measurements, we find that, for n-GaAs, transport occurs by both thermionic emission and tunneling, with the former dominating at low forward bias and the latter dominating at higher forward bias. For p-GaAs, tunneling dominates at all bias voltages. By combining the analysis of the transport data with results from direct and inverse photoemission spectroscopy, we deduce an energy band diagram of the system, including the tunnel barrier and, with this barrier and within the Simmons tunneling model, extract an effective mass value of 1.5−1.6me for the electronic carriers that cross the junctions. We find that transport is well-described by lowest unoccupied and highest occupied states at 1.3−1.4 eV above and 2.0−2.2 eV below the Fermi level. At the same time, the photoemission data indicate that there are continua of states from the conduction band minimum and the va...
TL;DR: In this paper, the generalized Skyrme effective force (GSEF) is parametrized by the fit to several properties of the normal and isospin-rich nuclei.
Abstract: We parametrize the recently proposed generalized Skyrme effective force (GSEF) containing extended density dependence. The parameters of the GSEF are determined by the fit to several properties of the normal and isospin-rich nuclei. We also include in our fit a realistic equation of state for the pure neutron matter up to high densities so that the resulting Skyrme parameters can be suitably used to model the neutron star with the 'canonical' mass ({approx}1.4M{sub {center_dot}}). For the appropriate comparison, we generate a parameter set for the standard Skyrme effective force (SSEF) using exactly the same set data as employed to determine the parameters of the GSEF. We find that the GSEF yields larger values for the neutron skin thickness which are closer to the recent predictions based on the isospin diffusion data. The Skyrme parameters so obtained are employed to compute the strength function for the isoscalar giant monopole, dipole, and quadrupole resonances. It is found that in the case of GSEF, because of the larger value of the nucleon effective mass, the values of centroid energies for the isoscalar giant resonances are in better agreement with the corresponding experimental data than those obtained using the SSEF. We also present resultsmore » for some of the key properties associated with the neutron star of canonical mass and for the one with the maximum mass.« less
TL;DR: In this article, the authors measured the reflectivity spectra of the first-row transition metal intercalation complexes, M1/3NbS2 and M 1/3TaS2 (M = V, Cr, Mn, Fe, Co, Ni), and compared with those for the host compounds.
Abstract: Optical reflectivity spectra of the first-row transition metal intercalation complexes, M1/3NbS2 and M1/3TaS2 (M = V, Cr, Mn, Fe, Co, Ni), Mn1/4 TaS2 and Fe1/4 NbSe2 have been measured at room temperature and compared with those for the host compounds, 2H NbS2, 2H TaS2 and 2H NbSe2. It is found that a simple rigid-band model is inconsistent with the data and that it is necessary to include both broadening of the valence and the lowest conduction band through increased interlayer interactions and broadening of the 3d energy levels on the intercalate ions through interaction with the Nb or Ta d-band conduction electrons. Quantitative analysis of the free-carrier reflectivity edge is performed by fitting to a simple Drude model from which the free-carrier effective mass and scattering time can be deduced.
TL;DR: In this paper, the decay of the interaction and the correlation functions is proven and the dependence of the correlation length on band gap and effective mass is derived for both critical and non-critical cases.
Abstract: We investigate bosonic Gaussian quantum states on an infinite cubic lattice in arbitrary spatial dimensions. We derive general properties of such states as ground states of quadratic Hamiltonians for both critical and non-critical cases. Tight analytic relations between the decay of the interaction and the correlation functions are proven and the dependence of the correlation length on band gap and effective mass is derived. We show that properties of critical ground states depend on the gap of the point-symmetrized rather than on that of the original Hamiltonian. For critical systems with polynomially decaying interactions logarithmic deviations from polynomially decaying correlation functions are found.
TL;DR: The inner layers of a neutron star crust, composed of a Coulomb lattice of neutron rich nuclear clusters immersed in a sea of free superfluid neutrons, are closely analogous to periodic condensed matter systems such as electronic, photonic or phononic crystals.
TL;DR: In this paper, the D -meson spectral density at finite temperature is obtained within a self-consistent coupled-channel approach, whose parameters are fixed by the position and width of the Λ c (2593 ) resonance.
TL;DR: In this article, the authors investigated the structure of the order parameter and its response to disorder for the most symmetric pairing state for the Fermion superconductor and determined characteristic properties of the superconducting instability.
Abstract: In materials without an inversion center of symmetry the spin
degeneracy of the conducting band is lifted by an antisymmetric
spin orbit coupling (ASOC). Under such circumstances, spin and
parity cannot be separately used to classify the Cooper pairing
states. Consequently, the superconducting order parameter is
generally a mixture of spin singlet and triplet pairing states. In
this paper we investigate the structure of the order parameter and
its response to disorder for the most symmetric pairing state
(A1). Using the example of the heavy Fermion superconductor
CePt3Si, we determine characteristic properties of the
superconducting instability. Depending on the type of the
pairing interaction, the gap function is characterized
by the presence of line nodes. We show that this line nodes move in general
upon temperature.
Such nodes would be essential to explain recent low-temperature
data of thermodynamic quantities such as the NMR-T1
-1,
London penetration depth, and heat conductance.
Moreover, we study the effect of (non-magnetic) impurity on the superconducting state.
TL;DR: In this paper, the problem of the self-interaction of a quasi-rigid classical particle with an arbitrary spherically symmetric charge distribution is completely solved up to the first order in the acceleration.
Abstract: The problem of the self-interaction of a quasi-rigid classical particle with an arbitrary spherically symmetric charge distribution is completely solved up to the first order in the acceleration No ad hoc assumptions are made The relativistic equations of conservation of energy and momentum in a continuous medium are used The electromagnetic fields are calculated in the reference frame of instantaneous rest using the Coulomb gauge; in this way the troublesome power expansion is avoided Most of the puzzles that this problem has aroused are due to the inertia of the negative pressure that equilibrates the electrostatic repulsion inside the particle The effective mass of this pressure is −Ue/(3c2), where Ue is the electrostatic energy When the pressure mass is taken into account the dressed mass m turns out to be the bare mass plus the electrostatic mass m = m0 + Ue/c2 It is shown that a proper mechanical behaviour requires that m0 > Ue/3c2 This condition poses a lower bound on the radius that a particle of a given bare mass and charge may have The violation of this condition is the reason why the Lorentz–Abraham–Dirac formula for the radiation reaction of a point charge predicts unphysical motions that run away or violate causality Provided the mass condition is met the solutions of the exact equation of motion never run away and conform to causality and conservation of energy and momentum When the radius is much smaller than the wavelength of the radiated fields, but the mass condition is still met, the exact expression reduces to the formula that Rohrlich (2002 Phys Lett A 303 307) has advocated for the radiation reaction of a quasi-point charge
TL;DR: In this article, an X-ray line broadening technique was used to estimate the average crystal radius of as-deposited bismuth(III) sulfide thin film material.
TL;DR: In this paper, it was shown that the reverse bias leakage current may be caused by the temperature dependence of the electron tunneling rate from traps in the metal-semiconductor interface to the conduction band of the semiconductor.
Abstract: Temperature-dependent reverse-bias current-voltage data obtained by Miller et al. [Appl. Phys. Lett. 84, 535 (2004)] for Schottky diodes fabricated on n-GaN are reinterpreted in terms of a phonon-assisted tunneling model. It is shown that the temperature dependence of the reverse-bias leakage current may be caused by the temperature dependence of the electron tunneling rate from traps in the metal-semiconductor interface to the conduction band of the semiconductor. A good fit of the experimental data with this theoretical model is obtained in the entire temperature range from 80to400K, when an effective mass of 0.222me and a phonon energy of 70meV are used for the calculation. The reverse current-voltage data for GaN diodes are also explained on the basis of this model.