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This investigation delves into the adsorption characteristics of CO, NO, NO 2 , NH 3 , and O 2 on two-dimensional (2D) Janus group-III materials, specifically Al 2 XY and B 2 XY. The examination covers adsorption energies and heights, diverse adsorption sites, and molecular orientations. Employing first-principles analysis, a comprehensive assessment of structural, electronic, and optical properties is conducted. The findings highlight NO 2 as a prominent adsorbate, emphasizing the Te surface of 2D Al 2 STe and B 2 STe materials as particularly adept for NO 2 detection, based on considerations of adsorption energy, height, and charge transfer. Additionally, the study underscores the heightened sensitivity of work function changes in the B 2 STe material. The adsorption properties of all gas molecules, except for NO 2 , on both materials were determined to be physical. Upon adsorption of the NO 2 gas molecule onto the B 2 STe Janus material, it was observed that the material exhibited weak chemical adsorption behavior, which was confirmed by the adsorption energy, larger band gap change, electron localization function, work function changes and charge transfer from the material. This research provides valuable insights into the gas-sensing potential of 2D Janus materials.

On the basis of first-principles calculations, we investigate the absorption of fluorine and chlorine on ferromagnetic monolayer CrN focusing on the mechanism of spin reorientation. We use density functional theory in combination with the spin Hamiltonian approach to study the electronic and magnetic properties of monolayer CrN upon single-side adsorption of F and Cl atoms. While the electronic structure of ferromagnetic CrN remains half-metallic after functionalization, its preferred axis of magnetization is rotated toward the in-plane direction due to the orbital moment suppression. The half-coverage of CrN is found to be thermodynamically stable and ferromagnetically ordered at room temperature. Our findings demonstrate the possibility of altering the magnetic properties of a two-dimensional magnet after the adsorption of F and Cl, which opens a route to the detection of these gases using magnetic or optical measurements.

Two-dimensional materials are leading the way in nanodevice applications thanks to their various advantages. Although two-dimensional materials show promise for many applications, they have certain limitations. In the last decade, the increasing demand for the applications of novel two-dimensional materials has accelerated heterostructure studies in this field. Hence, restoring the combination of two-dimensional heterostructured materials has been reported. In this paper, we show that the effect of the external electric field and biaxial strain on the silicene/Ga 2 SeS heterostructure has a critical impact on the tuning of the Schottky barrier height. The findings such as the variation of the electronic band gap, interlayer charge transfer, total dipole moment, and n-type/p-type Schottky barrier transitions of the silicene/Ga 2 SeS heterostructure under external effects imply that the device performance can be adjusted with Janus 2D materials.

The van der Waals (vdW) heterostructures are emerging as promising structures for future possible optoelectronic devices. Motivated by the recent studies on vdW heterostructures with their fascinating physical properties, we investigate the electronic and optical properties of boron phosphide/blue phosphorus heterostructures in the framework of density functional theory (DFT) and tight-binding (TB) approximations. We analyze the variation of the energy band gap, the characteristics of the energy band diagram, charge redistribution by stacking and the electrostatic potential along the perpendicular direction. The dynamical stability of these structures is ensured by the phonon spectra. We show that trilayer heterostructures of boron phosphide/bilayer blue phosphorus are in-direct band gap semiconductors while heterobilayers have a direct band gap at the K point. Moreover, we examine the optical properties of monolayer boron phosphide and heterostructures as part of DFT calculations. We conclude that the heterostructures have remarkable optical absorption over the UV range together with being transparent to the visible spectrum, and may be a prominent material for future optoelectronic devices.