Stable Sulfuric Vapor Transport and Liquid Sulfur Growth on Transition Metal Dichalcogenides

Transition metal dichalcogenides (TMDs) are an emergent class of low-dimensional materials with growing applications in the field of nanoelectronics. However, efficient methods for synthesizing large monocrystals of these systems are still lacking. Here, we describe an efficient synthetic route for a large number of TMDs that were obtained in quartz glass ampoules by sulfuric vapor transport and liquid sulfur. Unlike the sublimation technique, the metal enters the gas phase in the form of molecules, hence containing a greater amount of sulfur than the growing crystal. We have investigated the physical properties for a selection of these crystals and compared them to state-of-the-art findings reported in the literature. The acquired electronic properties features demonstrate the overall high quality of single crystals grown in this work as exemplified by CoS₂, ReS₂, NbS₂, and TaS₂. This new approach to synthesize high-quality TMD single crystals can alleviate many material quality concerns and is suitable for emerging electronic devices.