First principles studies on electronic and contact properties of Single layer 2H-MoS2/1T'-MX2 heterojunctions

With in-plane heterojunction contacts between semiconducting 2H phase (as channel) and the metallic 1T' phase (as electrode), the two-dimensional (2D) transition metal chalcogenides (TMDs) field-effect transistors (FETs) have received much...

Interface Engineering of Heterogeneous Transition Metal Chalcogenides for Electrocatalytic Hydrogen Evolution

MoS2 and MoSe2 are recognized as the promising electrocatalysts for hydrogen evolution reaction (HER), but the active sites are mainly located on the edge, limiting their electrochemical efficiency. Here we...

Emergent high superconductivity in layered TaS3 crystal

Transition metal chalcogenides (TMCs) have attracted increasing attention due to their rich polymorphs and unique properties, i.e. pressure-induced superconductivity. In this work, we systematically investigated phase diagram, stability, and superconducting...

Recent Progress and Approaches on Transition Metal Chalcogenides for Hydrogen Production

Development of efficient and affordable photocatalysts is of great significance for energy production and environmental sustainability. Transition metal chalcogenides (TMCs) with particle sizes in the 1–100 nm have been used for various applications such as photocatalysis, photovoltaic, and energy storage due to their quantum confinement effect, optoelectronic behavior, and their stability. In particular, TMCs and their heterostructures have great potential as an emerging inexpensive and sustainable alternative to metal-based catalysts for hydrogen evolution. Herein, the methods used for the fabrication of TMCs, characterization techniques employed, and the different methods of solar hydrogen production by using different TMCs as photocatalyst are reviewed. This review provides a summary of TMC photocatalysts for hydrogen production.

Electronic structure and spin-orbit coupling in ternary transition metal chalcogenides Cu2TlX 2 (X=Se, Te)

Ternary transition metal chalcogenides provide a rich platform to search and study intriguing electronic properties. Using Angle-Resolved Photoemission Spectroscopy and ab initio calculation, we investigate the electronic structure of Cu2TlX 2 (X = Se, Te), ternary transition metal chalcogenides with quasi-two-dimensional crystal structure. The band dispersions near the Fermi level are mainly contributed by the Te/Se p orbitals. According to our ab-initio calculation, the electronic structure changes from a semiconductor with indirect band gap in Cu2TlSe2 to a semimetal in Cu2TlTe2, suggesting a band-gap tunability with the composition of Se and Te. By comparing ARPES experimental data with the calculated results, we identify strong modulation of the band structure by spin-orbit coupling in the compounds. Our results provide a ternary platform to study and engineer the electronic properties of transition metal chalcogenides related to large spin-orbit coupling.

Intercalation in 2D transition metal chalcogenides: interlayer engineering and applications

Intercalation is basically a process of putting one or multiple guest elements in the van der Waals (vdW) gaps of a parent crystal in a reversible way. Two-dimensional (2D) materials showed great promise for different intercalant species ranging from organic molecules to ions. Apart from graphene, the most studied 2D materials are the transition metal di-chalcogenides (TMDs). The intercalation in TMDs has reinvented the strategies beyond graphene in 2D structure in material science, materials engineering, chemistry, and physics. This review deals with the possible mechanism as well as the window that intercalation can open for compact and ultrathin device technology. Modulation of the physicochemical properties in the intercalated TMDs has been thoroughly reviewed. Finally, the device performance, especially energy storage and energy harvesting devices, has been evaluated, and specific issues have been chalked out that need attention for future development.