We perform first-principles calculations to investigate the structural, electronic, and vibrational properties of WS2, WSe2, WTe2 monolayers, taking into account strong spin orbit coupling. A transition from a direct an indirect band gap is achieved for compressive strain 1% 1.5% 2% WTe2, while nature remains in case tensile strain. The size passes through maximum under decreases monotonically splitting found valence all three compounds, which further enhanced by mobility electrons grows...

The structural, electronic, optical, and photocatalytic properties of out-of-plane in-plane heterostructures transition metal dichalcogenides are investigated by (hybrid) first principles calculations. found to be indirect band gap semiconductors with type-II alignment. Direct gaps can achieved moderate tensile strain in specific cases. excitonic peaks show blueshifts as compared the parent monolayer systems, whereas redshifts occur when chalcogen atoms exchanged along series S-Se-Te. Strong...

In this work, we construct an ultrathin graphene/GaS heterostructure and investigate its electronic properties as well the effect of vertical strain using density functional theory. The calculated results equilibrium interlayer spacing (3.356 Å) binding energy show that intrinsic isolated graphene GaS monolayers can be preserved weak van der Waals interactions are dominated in heterostructures. (vdWH) forms n-type Schottky contact with a small barrier height 0.51 eV. This also tuned by...

Vertical stacking of ultrathin two-dimensional materials via weak van der Waals (vdW) interactions is identified as an important technique for tuning the physical properties and designing viable products nanoelectronics, spintronics, renewable energy source applications. The geometry, electronic, photocatalytic vdW heterostructures GeC Janus transition metal dichalcogenides $M\mathrm{SSe}$ ($M$ = Mo, W) monolayers are investigated by performing first-principles calculations. Two different...

Janus monolayers and their van der Waals heterostuctures are investigated by hybrid density functional theory calculations. MoSSe, WSSe, MoSeTe WSeTe found to be direct band gap semiconductors. External electric fields used transform indirect MoSTe WSTe MoSSe-WSSe, MoSeTe-WSeTe MoSTe-WSTe vdW heterostructures also semiconductors with type-II alignment. Similar the corresponding monolayers, in some of above mentioned an external field tensile strain can gaps, while sustaining have lower...

A theoretical study of Al1−xGaxN, based on the full-potential linearized augmented plane wave method, is used to investigate variations in bandgap, optical properties, and nonlinear behavior compound with change Ga concentration. It found that bandgap decreases increase Ga. maximum value 5.50 eV determined for pure AlN, which reaches a minimum 3.0 when Al completely replaced by The static index refraction dielectric constant material, assigning high GaN compared AlN. refractive drops below 1...

Two-dimensional graphene-based van der Waals heterostructures have received considerable interest because of their intriguing characteristics compared with the constituent single-layer two-dimensional materials. Here, we investigate interfacial characteristics, Schottky contact, and optical performance $\mathrm{graphene}/{\mathrm{Ga}}_{2}\mathrm{SSe}$ (vdW) heterostructure using first-principles calculations. The effects stacking patterns, electric gating, interlayer coupling on properties...

Van der Waals heterostructures, created by putting graphene on other two-dimensional semiconducting materials, have become an effective strategy to enhance the physical properties and extend possible applications of (2D) materials. Motivated successful synthesis a graphene/${\mathrm{PbI}}_{2}$ heterostructure in recent experiment [Nat. Commun. 11, 823 (2020)], here we use first-principles calculations construct investigate electronic interface characteristics heterostructure. We find that...

The stacking of monolayers in the form van der Waals heterostructures is a useful strategy for band gap engineering and control dynamics excitons potential nano-electronic devices.

In this work, we have studied new double perovskite materials, A2 1+B2+B3+X6 1-, where 1+ = Cs, B2+ Li, Na, B3+ Al, Ga, In, and X6 1-. We used the all electron full-potential linearized augmented plane wave (FP-LAPW+lo) method within framework of density functional theory. mBJ approximation WC-GGA as exchange-correlation functionals. optimized lattice constants with WC-GGA. Band structures were calculated without spin-orbit coupling (SOC). Further, band for Cs2LiGaBr6 Cs2NaGaBr6 SOC + to...

Based on first-principles calculations, the materials properties (structural, electronic, vibrational, and optical properties) of out-of-plane heterostructures formed from transiti metal dichalcogenides, specifically MoS$_2$-WSe$_2$ WS$_2$-MoSe$_2$ were investigated. The are found to be direct ind irect band gap semiconductors, respectively. However, a in heterostructure can achieved by applying compressive strain. Furthermore, excitoni c peaks both monolayer bilayer calculated understand...

Combining van der Waals heterostructures by stacking different two-dimensional materials on top of each other layer-by-layer can enhance their desired properties and greatly extend the applications parent materials.

V-series nerve agents are very lethal to health and cause the inactivation of acetylcholinesterase which leads neuromuscular paralysis and, finally, death. Therefore, rapid detection elimination important. Herein, we have carried out a theoretical investigation carbon nitride quantum dots (C2N) as an electrochemical sensor for agents, including VX, VS, VE, VG, VM. Adsorption on C2N is explored at M05-2X/6-31++G(d,p) level theory. The theory chosen quite adequate in systems describing...

We use DFT to investigate the structural, formation energy, hydrogen storage, electronics, thermoelectric and elastic properties of NaXH 3 (X = Be, Mg, Ca, Sr) hydrides as potential storage materials.

Unstrained and biaxial tensile strained Ti₂CO₂, Zr₂CO₂, Hf₂CO₂can be used to oxidize H₂O into O₂, while compressed Ti₂CO₂fails O₂.

Based on (hybrid) first-principles calculations, material properties (structural, electronic, vibrational, optical, and photocatalytic) of van der Waals heterostructures their corresponding monolayers (transition metal dichalcogenides MXenes) are investigated.

Electronic structure, optical, and photocatalytic properties of P, BSe, SiC monolayers their van der Waals heterostructures are investigated by (hybrid) first-principle calculations. The stability the corresponding induced-strain/unstrain confirmed phonon spectra Similar to parent monolayers, P-BSe (BSe-SiC) indirect type-II (type-I) bandgap semiconductors. A tensile strain 10% (2%) transforms type-I (type-II) direct nature. Interestingly, irrespective P-SiC heterostructure is a...

Vertical stacking of two-dimensional materials into layered van der Waals heterostructures has recently been considered as a promising candidate for photocatalytic and optoelectronic devices because it can combine the advantages individual 2D materials. Janus transition metal dichalcogenides (JTMDCs) have emerged an appealing material due to desirable electronic properties. Hence, in this work, we systematically investigate geometric features, properties, charge density difference, work...

The geometric structure, electronic, optical and photocatalytic properties of MSSe-g-GaN (M = Mo, W) van der Waals (vdW) heterostructures are investigated by performing first-principles calculations. We find that the MoSSe-g-GaN heterostructure exhibits type-II band alignment for all stacking patterns. While WSSe-g-GaN forms or type-I model-I model II, respectively. average electrostatic potential shows g-GaN is deeper than MSSe monolayer, leading to formation an field across interface,...