Defect Engineering within Transition Metal Dichalcogenides Using Magnetic and Rare-Earth Metals

Monolayer transition metal dichalcogenides (TMDs), such as WS₂ and WSe₂, have gained substantial interest for point-defect control, serving as host substrates for quantum emitters, exhibiting spin-valley splitting properties, and showing capability towards tunable band gap engineering. Sulfur vacancies can be controllably created to serve as target sites for photo- and spin- active functionalization [e.g., decorated cobalt or rare-earth atoms in TMDs]. Scanning probe microscopy (held in ultra-high vacuum and low temperature) can measure the electronic characteristics at the atomic level of induced defects, while also providing a path to excite single-defect optical transitions. Here, we delve into filling defect vacancies in synthetic host TMD materials to enable investigations in localized photon emission, determine spin-orbit interaction, and identify subsequent band structure with scanning probe microscopy and spectroscopy. The nature and study of adsorbed metals on heterostructure materials, with induced defectivity and new routes for subsequent defect functionalization, provide growth and impact in the fields of next-generation color centers and two-dimensional quantum materials.