Electronic heat capacity and conductivity of gapped graphene

in this paper, we present a tight-binding model based on Dft calculations for investigation the electronic and optical properties of monolayer Germanene. the thermal properties are investigated using Green function method. the required tight binding parameters including the onsite energies and third nearest neighbors hopping and overlap integrals are obtained based on our Dft calculations. Germanene is a semiconductor with zero band gap and linear band dispersion around the K point. the band gap opening occurs in the presence of bias voltage. the band gap is increased linearly with increase of the bias voltage strength. The tight binding results for position of the two first peaks in the optical infrared region is same with the Dft results. By applying and increasing bias voltage, the dielectric function shows the blue shift by reduction the peak intensity in the energy range E < 1 eV. The thermal conductivity and heat capacity increase with increasing the temperature due to the increasing of thermal energy of charge carriers and excitation them to the conduction bands. the thermal properties of Germanene in the absence of bias U = 0 is larger than that U ≠ 0 and they decrease by further bias strength increasing, due to the increasing band gap with bias.Two-dimensional (2D) monolayer structures have been an active field of research due to their electronic, optical, and thermal properties. Graphene is a planar atomic layer of carbon atoms which they are arranged in a honeycomb lattice with 1.42 A° interatomic distance between two adjacent C atoms. Graphene has been an active field of research due to its important physical properties such as electronic structure with gapless properties, room temperature quantum Hall effects 1 and high intrinsic mobility 2 .In the graphene, the existence of a zero gap is due to the crossing between the valence and conduction bands at the K point (Dirac point). Near the K point, graphene exhibits linear energy dispersion in terms of momentum and its charge carriers behave as relativistic massless Dirac fermions described by a Dirac-like equation 3 . Note that, Materials with a zero band gap energy exhibit some fascinating and superior electronic properties compared to materials with a non-zero energy gap and they have intriguing physical properties and numerous potential practical applications in spintronics, electronics, optics and sensors 4 . The Dirac Spin-gapless semiconductors, have high carrier mobility and due to their real massless fermions and dissipation-less transport properties, they are regarded as promising candidates for applications in ultra-fast and ultra-low-power spintronic devices 5,6 .Several studies on electronic and optical properties of monolayer graphene have been reported via Density functional Theory (DFT) and Tight binding Theory (TB) 7-11 . Due to the zero band gap in graphene, the light absorption occurs in a wide range of spectra from infrared (IR) to ultraviolet which lead to the use of graphene in electro-optical devices. Using the first nearest neigh...

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“…The paramagnetic susceptibility and electronic heat capacity is defined by the following expressions 36 :…”

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confidence: 99%

Tunable Electronic, Optical, and Thermal Properties of two- dimensional Germanene via an external electric field

Chegel

Behzad

2020

Sci Rep

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“…Conceivably, the larger cell of this kind is chosen, the more reliable picture of real DNA it resembles. The second quantization form of the TB Hamiltonian model reads as [39][40][41] H ¼ X Nc…”

Section: Model and Approachmentioning

confidence: 99%

“…Consequently, using Green's functions formalism [37][38][39][40][41], for a lattice with a total number of N a ¼ 2N s molecular sites in each unit cell, Green's function is a N a Â N a matrix with elements G αβ μν ði; j; τÞ ¼ À〈Tĉ α i;μ ðτÞĉ β † j;ν ð0Þ〉; where τ ¼ ıt denotes the imaginary time, T is the time ordering operator, and 〈⋯〉 indicates ensemble averaging over the ground state of the system. The dynamical equations for the operators, dĉ α i;μ ðτÞ=dτ ¼ ½ĤðτÞ;ĉ α i;μ ðτÞ, lead then to the dynamical equations for the corresponding Green's function:…”

Section: Model and Approachmentioning

confidence: 99%

“…Here in this work, with exclusive regard for π-stacked electrons [7,9,10] of the sugar-phosphate backbone, and using Green's functions formalism [37][38][39][40][41] applied to TB Hamiltonian of a twochain DNA model [26][27][28], we calculate the band structure (BS) and density of states (DOS) under both dry and wet ambient conditions. For this purpose, we will study some randomly arranged sequences of the base pairs under the above-mentioned conditions, as a general but still simple method to judge the electronic behavior of the DNA.…”

Section: Introductionmentioning

confidence: 99%

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Electronic properties of long DNA nanowires in dry and wet conditions

Mousavi¹,

Khodadadi²,

Grabowski³

2015

Solid State Communications

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“…The 21st century has brought many new results related to graphene thermodynamics. [32][33][34][35][36][37][38][39][40][41][42][43][44][45] Apparently, the thermodynamics of graphene has been characterized from many points of view; however, the role of the Lifshitz topological transitions in the thermodynamic properties of graphene has not been studied. This paper aims to close this gap.…”

Section: Introductionmentioning

confidence: 99%