-Symmetry Breaking and Spin Control in 2D Antiferromagnetic MnSe.

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 of discrete crystal symmetries (such as inversion ( ), time-reversal ( ), or combined symmetry) of 2D semiconducting AFM manganese selenide (MnSe) and external electric field along with graphene proximity is investigated. We show that both an external electric field and graphene proximity can independently break otherwise conserved combined symmetry in 2D MnSe, resulting in large and tunable spin-splittings in both valence and conduction bands, and provide electrical control over a wide energy range.

Reversible Transition of Semiconducting PtSe and Metallic PtTe for Scalable All-2D Edge-Contacted FETs.

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 in scaled-up FETs remains challenging due to their van der Waals (vdW) bonding nature with respect to conventional metal electrodes. Herein, we report a scalable approach to fabricate centimeter-scale all-2D FET arrays of platinum diselenide (PtSe) with in-plane platinum ditelluride (PtTe) edge contacts, mitigating the aforementioned challenges.

Peel-and-Stick Integration of Atomically Thin Nonlayered PtS Semiconductors for Multidimensionally Stretchable Electronic Devices.

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 crystals is rather limited in nature as they are only obtained from certain mother crystals with intrinsically possessed layered crystallinity and anisotropic molecular bonding. Recent efforts to transform conventionally non-vdW three-dimensional (3D) crystals into ultrathin 2D-like structures have seen rapid developments to explore device building blocks of unique form factors.

Hydrogen Storage in Bilayer Hexagonal Boron Nitride: A First-Principles Study.

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

Rashba Effect and Raman Spectra of TlO/PtS Heterostructure.

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 to study the electronic and spintronic properties of TlO/PtS heterostructure, for which we have confirmed the dynamical stability by its positive phonon frequencies. An unexpectedly high binding energy of -0.

Large-area 2D PtTe/silicon vertical-junction devices with ultrafast and high-sensitivity photodetection and photovoltaic enhancement by integrating water droplets.

2D PtTe2 layers, a relatively new class of 2D crystals, have unique band structure and remarkably high electrical conductivity promising for emergent opto-electronics. This intrinsic superiority can be further leveraged toward practical device applications by merging them with mature 3D semiconductors, which has remained largely unexplored. Herein, we explored 2D/3D heterojunction devices by directly growing large-area (>cm2) 2D PtTe2 layers on Si wafers using a low-temperature CVD method and unveiled their superior opto-electrical characteristics.

Wafer-Scale Growth of 2D PtTe with Layer Orientation Tunable High Electrical Conductivity and Superior Hydrophobicity.

Platinum ditelluride (PtTe) 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 and controllable synthesis of large-area 2D PtTe with well-defined layer orientation has not been established, leaving its projected structure-property relationship largely unclarified. Herein, we report a scalable low-temperature growth of 2D PtTe layers on an area greater than a few square centimeters by reacting Pt thin films of controlled thickness with vaporized tellurium at 400 °C.

Silicene on Monolayer PtSe: From Strong to Weak Binding via NH Intercalation.

We study the properties of silicene on monolayer PtSe by first-principles calculations and demonstrate a much stronger interlayer interaction than previously reported for silicene on other semiconducting substrates. This fact opens the possibility of a direct growth. A band gap of 165 meV results from inversion symmetry breaking and large spin-splittings in the valence and conduction bands from proximity to monolayer PtSe and its strong spin-orbit coupling.

Electronic Properties of Graphene-PtSe Contacts.

In this article, we study the electronic properties of graphene in contact with monolayer and bilayer PtSe using first-principles calculations. It turns out that there is no charge transfer between the components because of the weak van der Waals interaction. We calculate the work functions of monolayer and bilayer PtSe and analyze the band bending at the contact with graphene.