In Situ Characterization of Transformations in Nanoscale Layered Metal Chalcogenide Materials: A Review

Abstract Layered metal chalcogenide materials, such as MoS₂ and Bi₂Te₃, have found important applications as 2D materials in emerging electronic devices. To create nanoscale layered chalcogenide materials with precisely controlled structures and properties, it is critical to understand and control how they evolve and transform under various conditions. This Minireview presents an overview of recent research focused on using in situ characterization to understand the atomic‐scale details of transformations during growth, under exposure to reactive chemical and thermal environments, and on interfacing with other materials. These efforts have used techniques including in situ transmission electron microscopy (TEM), X‐ray spectroscopy, and optical methods to understand nanoscale transformations. These in situ studies have provided a substantially improved understanding of transformation mechanisms in layered chalcogenide materials, which is an important step toward the use of these interesting materials in a variety of electronic and electrochemical devices.