transport model to study the thermoelectric performance of MoS, MoSe, and WSmonolayers by using Boltzmann transport equation.

The potential for thermoelectric applications of two-dimensional materials is quite promising. Using-calculations, we have investigated the electronic band structure, phonon band structure, electronic density of states, and phonon density of states of monolayers MoS, MoSe, and WS. In order to compute the thermoelectric properties of monolayers MoS, MoSe, and WS, we used the-model suggested by Faghaninia(2015B235123).

Quantum magneto-transport properties of monolayers MoSiN, WSiN, and MoSiAs.

We study the transport properties of monolayers MoSiN, WSiN, and MoSiAsin a perpendicular magnetic field. The Landau level (LL) band structures including spin and exchange field effects are derived and discussed using a low-energy effective model. We show that the LLs band structures of these materials are similar to those of phosphorene and transition-metal dichalcogenides rather than graphene or silicene.

Quantum Oscillations of the Energy Loss Rate of Hot Electrons in Graphene at Strong Magnetic Fields.

We present a theoretical model for the calculation of the energy loss rate (ELR) of hot electrons in a monolayer graphene due to their coupling with acoustic phonons at high perpendicular magnetic fields. Electrons interact with both transverse acoustic (TA) and longitudinal acoustic (LA) phonons. Numerical simulations of the ELR are performed as a function of the magnetic field, the electron temperature, the electron density, and the Landau level broadening.

Phonon-drag thermopower and thermoelectric performance of MoSmonolayer in quantizing magnetic field.

We present a theory of phonon-drag thermopower,Sxxg, in MoSmonolayer at a low-temperature regime in the presence of a quantizing magnetic field. Our calculations forSxxgconsider the electron-acoustic phonon interaction via deformation potential (DP) and piezoelectric (PE) couplings for longitudinal (LA) and transverse (TA) phonon modes. The unscreened TA-DP is found to dominateSxxgover other mechanisms.

Magneto-optical absorption properties of topological insulator thin films.

We theoretically study the magneto-optical absorption coefficients (MOACs) and the refractive index changes (RICs) due to both intra- and inter-band transitions in topological insulator (TI) thin films. The interplay between Zeeman energy and hybridization contribution leads to a transition between the normal insulator phase and the TI phase. The difference in the optical response in these two phases as well as at the phase transition point has been analyzed.

Giant thermopower and power factor in magic angle twisted bilayer graphene at low temperature.

The in-plane phonon-drag thermopower, diffusion thermopowerand the power factor PF are theoretically investigated in a twisted bilayer graphene (tBLG) as a function of twist angle, temperatureand electron densityin the region of low(1-20 K). Asapproaches magic angle, theandare found to be strongly enhanced, which is manifestation of great suppression of effective Fermi velocityof electrons in moiré flat band near. This enhancement decreases with increasingand.

Large power dissipation of hot Dirac fermions in twisted bilayer graphene.

We have carried out a theoretical investigation of hot electron power loss P, involving electron-acoustic phonon interaction, as a function of twist angle θ, electron temperature T and electron density n in twisted bilayer graphene. It is found that as θ decreases closer to magic angle θ , P enhances strongly and θ acts as an important tunable parameter, apart from T and n . In the range of T = 1-50 K, this enhancement is ∼250-450 times the P in monolayer graphene (MLG), which is manifestation of the great suppression of Fermi velocity v of electrons in moiré flat band.

A Novel Risk-Scoring Model for Prediction of Premalignant and Malignant Lesions of Uterine Endometrium Among Symptomatic Premenopausal Women.

Purpose: Uterine cancer is the second most prevalent cancer of the female genital tract, with 90% of it being of endometrial origin. The aim of this research was to create and validate a risk-scoring model using patients' clinical variables in predicting premalignant and malignant lesions of the uterine endometrium among premenopausal women with abnormal uterine bleeding (AUB).

Methods: This is a retrospective cohort study conducted at a tertiary hospital of Southern India for a period of 5 years from July 2014 to August 2019, including women aged ≤55 years who had AUB and underwent endometrial biopsy.

Drift velocity saturation and large current density in intrinsic three-dimensional Dirac semimetal cadmium arsenide.

Transport of electrons at high electric fields is investigated in intrinsic three-dimensional Dirac semimetal cadmium arsenide, considering the scattering of electrons from acoustic and optical phonons. Screening and hot phonon effect are taken in to account. Expressions for the hot electron mobility μ and power loss P are obtained as a function of electron temperature T .

Thermoelectric transport properties in 3D Dirac semimetal CdAs.

Thermoelectric transport properties, namely, electrical conductivity, electronic thermal conductivity, and diffusion thermopower are theoretically investigated in 3D Dirac semimetal CdAs. We employ Boltzmann transport formalism and consider the electron scattering by charged impurities, short-range disorder, acoustic phonons, and optical phonons. The Boltzmann transport equation is solved using the Ritz iteration technique to obtain the first-order perturbation distribution function for the interaction of electrons with inelastic polar optical phonons scattering.

Nanostructured p-TiO/n-GaN heterostructure as a potential photoelectrode for efficient charge separation.

This work proposes p-TiO/n-GaN as a new semiconductor heterostructure, which holds great promise as a photoelectrode material. To fabricate p-TiO/n-GaN heterostructures, wurtzite GaN is grown in two different morphologies by molecular beam epitaxy, and a TiO overlayer is formed by atomic layer deposition. The XRD and Raman experiments confirm the anatase crystal structure of TiO and SEM shows the conformal coating of TiO on GaN.

Hot electron cooling in Dirac semimetal CdAs due to polar optical phonons.

A theory of hot electron cooling power due to polar optical phonons P is developed in 3D Dirac semimetal (3DDS) CdAs taking account of hot phonon effect. Hot phonon distribution N and P are investigated as a function of electron temperature T , electron density n , and phonon relaxation time [Formula: see text]. It is found that P increases rapidly (slowly) with T at lower (higher) temperature regime.

Phonon-drag magnetoquantum oscillations in graphene.

A theory of low-temperature phonon-drag magnetothermopower [Formula: see text] is presented in graphene in a quantizing magnetic field. [Formula: see text] is found to exhibit quantum oscillations as a function of magnetic field B and electron concentration n . The amplitude of the oscillations is found to increase (decrease) with increasing B (n ).

Effects of a piezoelectric substrate on phonon-drag thermopower in monolayer graphene.

The phonon-drag thermopower is studied in a monolayer graphene on a piezoelectric substrate. The phonon-drag contribution [Formula: see text] from the extrinsic potential of piezoelectric surface acoustic (PA) phonons of a piezoelectric substrate (GaAs) is calculated as a function of temperature T and electron concentration n . At a very low temperature, [Formula: see text] is found to be much greater than [Formula: see text] of the intrinsic deformation potential of acoustic (DA) phonons of the graphene.

Phonon-drag thermopower in 3D Dirac semimetals.

A theory of low-temperature phonon-drag thermopower S(g) in three-dimensional (3D) Dirac semimetals has been developed considering screened electron-phonon deformation potential coupling. Numerical investigations of S(g), in the boundary scattering regime for phonons, are made in 3D Dirac semimetal Cd3As2, as a function of temperature T and electron concentration n e. S(g) is found to increase rapidly for about T  <  1 K and nearly levels off for higher T.

Phonon-drag thermopower in a monolayer MoS2.

The theory of phonon-drag thermopower S(g) is developed in a monolayer MoS(2), considering the electron–acoustic phonon interaction via deformation potential (DP) and piezoelectric (PE) coupling, as a function of temperature T and electron concentration n(s). DP coupling of TA (LA) phonons is taken to be unscreened (screened) and PE coupling of LA and TA phonons is taken to be screened. S(g) due to DP coupling of TA phonons is found to be dominant over all other mechanisms and in the Bloch–Grüneisen regime it gives power law S(g) ~ T3.

Phonon-drag thermopower in an armchair graphene nanoribbon.

We calculate the phonon-drag thermopower S(g) of an armchair graphene nanoribbon (AGNR) in the boundary scattering regime of phonons. S(g) is studied as a function of temperature, Fermi energy and width of the AGNR. At very low temperatures T, S(g) is exponentially suppressed and an activated behavior is observed which is characteristic of one-dimensional carriers.