Transition metal dichalcogenides are layered compounds, commonly written as MX2, in which a transition metal such as molybdenum, tungsten, titanium, or niobium is bonded to chalcogen atoms such as sulfur, selenium, or tellurium. Materials such as MoS2, WS2, MoSe2, and WSe2 are central examples. As two-dimensional materials, transition metal dichalcogenides can be studied as bulk crystals, few-layer flakes, monolayers, alloys, heterostructures, and patterned device materials with properties controlled by thickness, phase, strain, defects, and interfaces.
These materials matter because their electronic and optical behavior can change dramatically as they approach the monolayer limit. Many semiconducting TMDs show strong light-matter interaction, sizable band gaps, valley physics, excitons, and compatibility with flexible or atomically thin device architectures. They are investigated for transistors, photodetectors, light emitters, sensors, catalysis, spintronics, quantum emitters, and optoelectronics. Metallic and phase-engineered TMDs are also important for contacts, energy devices, and electrocatalysis.
Conference sessions on transition metal dichalcogenides appear in programs on nanotechnology, condensed-matter physics, photonics, energy, and van der Waals materials. Work is often organized around synthesis, chemical vapor deposition, spectroscopy, heterostructures, device physics, and applications. Tracking TMD events helps researchers follow one of the most active areas in layered semiconductors and atomically thin electronics.
To learn more, read our detailed glossary article on transition metal dichalcogenides.