Abstract
Due to their physical properties and potential applications in energy conversion and storage, transition-metal dichalcogenides (TMDs) have garnered substantial interest in recent years. Among this class of materials, TMDs based on molybdenum, tungsten, sulfur, and selenium are particularly attractive due to their semiconducting properties and the availability of bottom-up synthesis techniques. Here we report a method which yields high-quality crystals of transition-metal diselenide and ditelluride compounds (PtTe 2 , PdTe 2 , NiTe 2 , TaTe 2 , TiTe 2 , RuTe 2 , PtSe 2 , PdSe 2 , NbSe 2 , TiSe 2 , VSe 2 , ReSe 2 ) from their solid solutions, via vapor deposition from a metal-saturated chalcogen melt. Additionally, we show the synthesis of rare-earth-metal polychalcogenides and NbS 2 crystals using the aforementioned process. Most of the crystals obtained have a layered CdI 2 structure. We have investigated the physical properties of selected crystals and compared them to state of the art findings reported in the literature. Remarkably, the charge density wave transition in 1T-TiSe 2 and 2H-NbSe 2 crystals is well-defined at T CDW ≈ 200 and 33 K, respectively. Angle-resolved photoelectron spectroscopy and electron diffraction are used to directly access the electronic and crystal structures of PtTe 2 single crystals and yield state of the art measurements.