We report first-principles results on the thermal and thermoelectric properties of monolayer Tl2O. The lattice conductivity electronic transport coefficients are obtained by semiclassical Boltzmann theory. Monolayer Tl2O is found to be a semiconductor with direct band gap 1.62 eV. turns out ultralow, for example, 0.17 W/mK at 300 K. Combined high power factor, this in excellent performance. For 500 K p-type n-type figures merit reach peak values 0.96 0.94 hole electron concentrations 1.2 ×...

Platinum ditelluride (PtTe2) is an emerging semimetallic two-dimensional (2D) transition-metal dichalcogenide (TMDC) crystal with intriguing band structures and unusual topological properties. Despite much devoted efforts, scalable controllable synthesis of large-area 2D PtTe2 well-defined layer orientation has not been established, leaving its projected structure-property relationship largely unclarified. Herein, we report a low-temperature growth layers on area greater than few square...

In this article, we study the electronic properties of graphene in contact with monolayer and bilayer PtSe2 using first-principles calculations. It turns out that there is no charge transfer between components because weak van der Waals interaction. We calculate work functions analyze band bending at graphene. The formation an n-type Schottky a p-type demonstrated. barrier height very low case can be reduced to zero by 0.8% biaxial tensile strain.

Using first-principles calculations, we report on the structural and electronic properties of bilayer hexagonal boron nitride (h-BN), incorporating hydrogen (H2) molecules inside cavity for potential H2-storage applications. Decrease in binding energies desorption temperatures with an accompanying increase weight percentage (upto 4%) by increasing H2 molecular concentration hints at applicability this study. Moreover, highlight role different density functionals understanding decreasing...

We present first-principles results on the structural, electronic, and magnetic properties of a new family two-dimensional antiferromagnetic (AFM) manganese chalcogenides, namely, monolayer $\mathrm{Mn}X$ Janus $X\mathrm{Mn}Y$ ($X,Y=\mathrm{S}$, Se, Te), among which MnSe was recently synthesized in experiments [Aapro et al., ACS Nano 15, 13794 (2021)]. By carrying out calculations phonon dispersion ab initio molecular dynamics simulations, we first confirmed that these systems, characterized...

Understanding the nature of surface states and their exchange gaps in magnetic topological insulator MnBi$_2$Te$_4$ (MBT) thin films is crucial for achieving robust Chern Axion insulating phases where Quantum Anomalous Hall Effect Topological Magneto-electric can be realized. Here, we focus on rather unexplored issue how reconstructions, which are likely to occur experiments, influence these properties. Using first-principles calculations together with molecular dynamics simulations...

Novel photodetectors based on large-area 2D PtTe₂/silicon vertical-junctions exhibit ultra-fast photo-response, high sensitivity, and water-droplet driven photovoltaic enhancement.

Understanding the nature of surface states and their exchange gaps in magnetic topological insulator <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:msub><a:mi>MnBi</a:mi><a:mn>2</a:mn></a:msub><a:msub><a:mi>Te</a:mi><a:mn>4</a:mn></a:msub></a:mrow></a:math> (MBT) thin films is crucial for achieving robust Chern axion insulating phases where quantum anomalous Hall effect magneto-electric can be realized. Here we focus on some rather unexplored features possible...

Two-dimensional (2D) transition metal dichalcogenide (TMD) layers are highly promising as field-effect transistor (FET) channels in the atomic-scale limit. However, accomplishing this superiority scaled-up FETs remains challenging due to their van der Waals (vdW) bonding nature with respect conventional electrodes. Herein, we report a scalable approach fabricate centimeter-scale all-2D FET arrays of platinum diselenide (PtSe2) in-plane ditelluride (PtTe2) edge contacts, mitigating...

We use first-principles calculations to show that van der Waals (vdW) heterostructures consisting of few-layer Bi$_2$Se$_3$ and PtSe$_2$ exhibit electronic spintronics properties can be tuned by varying the constituent layers. Type-II band alignment with layer-tunable gaps type-III spin-splittings have been found. Most noticeably, we reveal coexistence Rashba-type (with large $α_{\rm R}$ parameters) in both conduction valence stemming from PtSe$_2$, respectively, which has confirmed...

Silicene and germanene are key materials for the field of valleytronics. However, interaction with substrate, which is necessary to support electronically active medium, becomes a major obstacle. In present work, we propose substrate (F-doped ${\mathrm{WS}}_{2}$) that avoids detrimental effects at same time induces required valley polarization, so no further steps needed this purpose. The behavior explained by proximity on silicene or germanene, as demonstrated first-principles calculations....

This study reports on the controlled vapor-phase anion exchange conversion of three-dimensional (3D) platinum(II) sulfide (PtS) thin films to two-dimensional platinum ditelluride (2D PtTe2) van der Waals (vdW) layers. The low temperature (i.e., 400 °C) thermal tellurization chemical vapor deposition (CVD)-grown PtS leads formation 2D PtTe2 vdW layers with a modulated crystallographic orientation, i.e., mixture horizontally and vertically oriented enables tunable electrical transport...

We study the structural and electronic properties of silicene on solid Ar(111) substrate using ab initio calculations. demonstrate that due to weak interaction, quasi-freestanding is realized in this system. The small binding energy only meV per Si atom also indicates possibility separate from substrate. In addition, a band gap 11 significant splitting levels spin-orbit coupling are observed.

Artificial heterojunctions formed by vertical stacking of dissimilar two-dimensional (2D) transition metal dichalcogenide (TMD) monolayer materials in a chosen sequence hold tantalizing prospects for futuristic atomically thin circuits. The emergence 2D topological insulators (TI), including Bi2Te3, Bi2Se3, and Sb2Te3, represents new class building blocks can complement the existing artificial as result their intriguing surface states protected time-reversal symmetry. However, determination...

Abstract The stacking effects on the electronic structure of van der Waals heterostructures consisting silicene and hexagonal boron nitride are investigated by first‐principles calculations. It is shown that fundamental for details dispersion relation in vicinity Fermi energy (gapped, non‐gapped, linear, parabolic) despite small differences total energy. also demonstrated tight‐binding model bilayer graphene able to capture most these features heterostructures, limitations identified.

Various near-atom-thickness two-dimensional (2D) van der Waals (vdW) crystals with unparalleled electromechanical properties have been explored for transformative devices. Currently, the availability of 2D vdW is rather limited in nature as they are only obtained from certain mother intrinsically possessed layered crystallinity and anisotropic molecular bonding. Recent efforts to transform conventionally non-vdW three-dimensional (3D) into ultrathin 2D-like structures seen rapid developments...

A direct band gap that solely exists in monolayer semiconducting transition metal dichalcogenides (TMDs) endows strong photoluminescence (PL) features, whereas multilayer TMD structures exhibit quenched PL due to the direct-to-indirect transition. We demonstrate (such as MoS2 and WS2) nanoscrolls with a preserved fabricated by an effective facile method of solvent-driven self-assembly. The resultant nanoscrolls, exhibiting up 11 times higher intensity than remanent monolayer, are carefully...

We study the properties of silicene on monolayer PtSe2 by first-principles calculations and demonstrate a much stronger interlayer interaction than previously reported for other semiconducting substrates. This fact opens possibility direct growth. A band gap 165 meV results from inversion symmetry breaking large spin-splittings in valence conduction bands proximity to its strong spin–orbit coupling. It is also shown that can be effectively reduced intercalating NH3 molecules between without...

Using first-principles calculations, we report structural and electronic properties of CO, NO2 NO molecular adsorption on β-In2Se3 in comparison to a previous study α-phase. Analysis energies extent charge transfer indicates be selective detecting gas molecules. We found molecules acting as donor whereas CO acceptors, respectively, experiencing physisorption all cases. Owing enhanced adsorption, faster desorption improved selectivity the discussed detail, conclude superior sensing material...

We reveal giant proximity-induced magnetism and valley-polarization effects in Janus Pt dichalcogenides (such as SPtSe), when bound to the Europium oxide (EuO) substrate. Using first-principles simulations, it is surprisingly found that charge redistribution, resulting from proximity with EuO, leads formation of two K K$^{'}$valleys conduction bands. Each these valleys displays its own spin polarization a specific spin-texture dictated by broken inversion time-reversal symmetries,...

The possibility to achieve charge-to-spin conversion via Rashba spin–orbit effects provides stimulating opportunities toward the development of nanoscale spintronics. Here, we use first-principles calculations study electronic and spintronic properties Tl2O/PtS2 heterostructure, for which have confirmed dynamical stability by its positive phonon frequencies. An unexpectedly high binding energy −0.38 eV per unit cell depicts strong interlayer interactions between Tl2O PtS2. Interestingly,...

We report on the experimental realization of Pb1-xSnxTe pentagonal nanowires (NWs) with [110] orientation using molecular beam epitaxy techniques. Using first-principles calculations, we investigate structural stability in NWs SnTe and PbTe three different phases: cubic, [001] orientation. Within a semiclassical approach, show that interplay between ionic covalent bonds favors formation NWs. Additionally, find this structure is more likely to occur tellurides than selenides. The disclination...

We report on the experimental realization of Pb1-xSnx Te pentagonal nanowires (NWs) with [110] orientation using molecular beam epitaxy techniques. Using first-principles calculations, we investigate structural stability NWs SnTe and PbTe in three different phases: cubic, [001] orientation. Within a semiclassical approach, show that interplay between ionic covalent bonds favors formation NWs. Additionally, find this structure is more likely to occur tellurides than selenides. The...

Two-dimensional (2D) materials with intrinsic antiferromagnetic (AFM) order provide a unique avenue to harness both charge and spin degrees of freedom for practical spintronics applications. Here, by using ab initio electronic structure calculations, the interplay discrete crystal symmetries (such as inversion (P ), time-reversal (T or combined PT symmetry) 2D semiconducting AFM manganese selenide (MnSe) external electric field along graphene proximity is investigated. We show that an can...