Exploring the versatility of MoSe/WS heterostructures.

Two-dimensional materials and their combined heterostructures have paved the way for numerous next-generation electronic and optoelectronic applications. Herein, we performed first principles calculations to computationally design the MoSe/WS heterostructure and consider its geometric structure, electronic properties and contact behavior, as well as the effects of the electric fields and strain. Our results show that the MoSe/WS heterostructure is energetically, thermodynamically and mechanically stable.

Piezoelectric GaGeX (X = N, P, and As) semiconductors with Raman activity and high carrier mobility for multifunctional applications: a first-principles simulation.

In the present work, we propose GaGeX (X = N, P, As) monolayers and explore their structural, vibrational, piezoelectric, electronic, and transport characteristics for multifunctional applications based on first-principles simulations. Our analyses of cohesive energy, phonon dispersion spectra, and molecular dynamics simulations indicate that the three proposed structures have good energetic, dynamic, and thermodynamic stabilities. The GaGeX are found as piezoelectric materials with high piezoelectric coefficient of -1.

Unveiling Versatile Electronic Properties and Contact Features of Metal-Semiconductor Graphene/γ-GeSSe van der Waals Heterostructures.

Recently, searching for a metal-semiconductor junction (MSJ) that exhibits low-contact resistance has received tremendous consideration, as they are essential components in next-generation field-effect transistors. In this work, we design a MSJ by integrating two-dimensional (2D) graphene as the metallic electrode and 2D Janus γ-GeSSe as the semiconducting channel using first-principles simulations. All the graphene/γ-GeSSe MSJs are predicted to be energetically, mechanically, and thermodynamically stable, characterized by the weak van der Waals (vdW) interactions.

Achieving ultra-low contact barriers in MX/SiH (M = Nb, Ta; X = S, Se) metal-semiconductor heterostructures: first-principles prediction.

Minimizing the contact barriers at the interface, forming between two different two-dimensional metals and semiconductors, is essential for designing high-performance optoelectronic devices. In this work, we design different types of metal-semiconductor heterostructures by combining 2D metallic MX (M = Nb, Hf; X = S, Se) and 2D semiconductor SiH and investigate systematically their electronic properties and contact characteristics using first principles calculations. We find that all the MX/SiH (M = Nb, Ta; X = S, Se) heterostructures are energetically stable, suggesting that they could potentially be synthesized in the future.

Large piezoelectric responses and ultra-high carrier mobility in Janus HfGeZH (Z = N, P, As) monolayers: a first-principles study.

Breaking structural symmetry in two-dimensional layered Janus materials can result in enhanced new phenomena and create additional degrees of piezoelectric responses. In this study, we theoretically design a series of Janus monolayers HfGeZH (Z = N, P, As) and investigate their structural characteristics, crystal stability, piezoelectric responses, electronic features, and carrier mobility using first-principles calculations. Phonon dispersion analysis confirms that HfGeZH monolayers are dynamically stable and their mechanical stability is also confirmed through the Born-Huang criteria.

First-principles investigations of the controllable electronic properties and contact types of type II MoTe/MoS van der Waals heterostructures.

Two-dimensional (2D) van der Waals (vdW) heterostructures are considered as promising candidates for realizing multifunctional applications, including photodetectors, field effect transistors and solar cells. In this work, we performed first-principles calculations to design a 2D vdW MoTe/MoS heterostructure and investigate its electronic properties, contact types and the impact of an electric field and in-plane biaxial strain. We find that the MoTe/MoS heterostructure is predicted to be structurally, thermally and mechanically stable.

Electron-phonon coupling effect on the optical absorption of gated β-borophene.

This study addresses the effect of electron-phonon coupling (EPC) on the electro-optical properties of gated β-borophene. The focus is on how EPC influences the orbital hybridization of boron atoms, particularly within the Bariśic-Labbe-Friedel-Su-Schrieffer-Heeger framework, and considers the role of gate electrodes in this process. The results reveal a redshift in the optical spectrum only when there is positive feedback from one electrode on EPC.

Electronic phase transition in bilayer 6 borophene.

In this study, using the tight-binding model and Green's function technique, we investigate potential electronic phase transitions in bilayer 6 borophene under the influence of external stimuli, including a perpendicular electric field, electron-hole coupling between sublayers (excitonic effects), and dopants. Our focus is on key electronic properties such as the band structure and density of states. Our findings reveal that the pristine lattice is metal with Dirac cones around the Fermi level, where their intersection forms a nodal line.

Theoretical prediction of electronic properties and contact barriers in a metal/semiconductor NbS/Janus MoSSe van der Waals heterostructure.

The emergence of van der Waals (vdW) heterostructures, which consist of vertically stacked two-dimensional (2D) materials held together by weak vdW interactions, has introduced an innovative avenue for tailoring nanoelectronic devices. In this study, we have theoretically designed a metal/semiconductor heterostructure composed of NbS and Janus MoSSe, and conducted a thorough investigation of its electronic properties and the formation of contact barriers through first-principles calculations. The effects of stacking configurations and the influence of external electric fields in enhancing the tunability of the NbS/Janus MoSSe heterostructure are also explored.

Tunable Electronic Properties, Carrier Mobility, and Contact Characteristics in Type-II BSe/ScCF Heterostructures toward Next-Generation Optoelectronic Devices.

Conducting heterostructures have emerged as a promising strategy to enhance physical properties and unlock the potential application of such materials. Herein, we conduct and investigate the electronic and transport properties of the BSe/ScCF heterostructure using first-principles calculations. The BSe/ScCF heterostructure is structurally and thermodynamically stable, indicating that it can be feasible for further experiments.

First-principles investigations of metal-semiconductor MoSH@MoS van der Waals heterostructures.

Two-dimensional (2D) metal-semiconductor heterostructures play a critical role in the development of modern electronics technology, offering a platform for tailored electronic behavior and enhanced device performance. Herein, we construct a novel 2D metal-semiconductor MoSH@MoS heterostructure and investigate its structures, electronic properties and contact characteristics using first-principles investigations. We find that the MoSH@MoS heterostructure exhibits a p-type Schottky contact, where the specific Schottky barrier height varies depending on the stacking configurations employed.

On the impact of adsorbed gas molecules on the anisotropic electro-optical properties of β-borophene.

We theoretically study the role of adsorbed gas molecules on the electronic and optical properties of monolayer β-borophene with {a,b,c,d,e} atoms in its unit cell. We focus our attention on molecules NH, NO, NO, and CO, which provide additional states permitted by the host electrons. Utilizing the six-band tight-binding model based on an inversion symmetry (between {a,e} and {b,d} atoms) and the Kubo formalism, we survey the anisotropic electronic dispersion and the optical multi-interband spectrum produced by molecule-boron coupling.

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.

Two-dimensional Janus MGeSiP (M = Ti, Zr, and Hf) with an indirect band gap and high carrier mobilities: first-principles calculations.

Novel Janus materials have attracted broad interest due to the outstanding properties created by their out-of-plane asymmetry, with increasing theoretical exploration and more reports of successful fabrication in recent years. Here, we construct and explore the crystal structures, stabilities, electronic band structures, and transport properties - including carrier mobilities - of two-dimensional Janus MGeSiP (M = Ti, Zr, or Hf) monolayers based on density functional theory calculations. From the cohesive energies, elastic constants, and phonon dispersion calculations, the monolayers are confirmed to exhibit structural stability with high feasibility for experimental synthesis.

Rashba-type spin splitting and transport properties of novel Janus XWGeN (X = O, S, Se, Te) monolayers.

We discuss and examine the stability, electronic properties, and transport characteristics of asymmetric monolayers XWGeN (X = O, S, Se, Te) using density functional theory. All four monolayers of quintuple-layer atomic Janus XWGeN are predicted to be stable and they are all indirect semiconductors in the ground state. When the spin-orbit coupling (SOC) is included, a large spin splitting at the point is found in XWGeN monolayers, particularly, a giant Rashba-type spin splitting is observed around the point in three structures SWGeN, SeWGeN, and TeWGeN.

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.

Theoretical prediction of Janus PdXO (X = S, Se, Te) monolayers: structural, electronic, and transport properties.

Due to the broken vertical symmetry, the Janus material possesses many extraordinary physico-chemical and mechanical properties that cannot be found in original symmetric materials. In this paper, we study in detail the structural, electronic, and transport properties of 1T Janus PdXO monolayers (X = S, Se, Te) by means of density functional theory. PdXO monolayers are observed to be stable based on the analysis of the vibrational characteristics and molecular dynamics simulations.

First-principles insights onto structural, electronic and optical properties of Janus monolayers CrXO (X = S, Se, Te).

The lacking of the vertical mirror symmetry in Janus structures compared to their conventional metal monochalcogenides/dichalcogenides leads to their characteristic properties, which are predicted to play significant roles for various promising applications. In this framework, we systematically examine the structural, mechanical, electronic, and optical properties of the two-dimensional 2H Janus CrXO (X = S, Se, Te) monolayers by using first-principles calculation method based on density functional theory. The obtained results from optimization, phonon spectra, and elastic constants demonstrate that all three Janus monolayers present good structural and mechanical stabilities.

Outstanding elastic, electronic, transport and optical properties of a novel layered material CF: first-principles study.

Motivated by very recent successful experimental transformation of AB-stacking bilayer graphene into fluorinated single-layer diamond (namely fluorinated diamane CF) [P. V. Bakharev, M.

Novel Janus GaInX (X = S, Se, Te) single-layers: first-principles prediction on structural, electronic, and transport properties.

In this paper, the structural, electronic, and transport properties of Janus GaInX (X = S, Se, Te) single-layers are investigated by a first-principles calculations. All three structures of GaInX are examined to be stable based on the analysis of their phonon dispersions, cohesive energy, and Born's criteria for mechanical stability. At the ground state, The Janus GaInX is a semiconductor in which its bandgap decreases as the chalcogen element X moves from S to Te.

Structural, electronic, and transport properties of Janus GaIn(S, Se, Te) monolayers: first-principles study.

Two-dimensional Janus monolayers have outstanding electronic and transport properties due to their asymmetric atomic structures. In the present work, we systematically study the structural, electronic, and transport properties of the Janus GaIn(= S, Se, Te) monolayers by using the first-principles calculations. The stability of the investigated monolayers is confirmed via the analysis of vibrational spectrum and molecular dynamics simulations.

Two-Dimensional Boron Phosphide/MoGeN van der Waals Heterostructure: A Promising Tunable Optoelectronic Material.

A van der Waals (VDW) heterostructure offers an effective strategy to create designer physical properties in vertically stacked two-dimensional (2D) materials, and offers a new paradigm in designing novel 2D heterostructure devices. In this work, we investigate the structural and electronic features of the BP/MoGeN heterostructure. We show that the BP/MoGeN heterostructure exists in a multiple structurally stable stacking configuration, thus revealing the experimental feasibility of fabricating such heterostructures.