Progress on the Intrinsic Grain Boundary Structures in Air-Sensitive Transition Metal Tellurides

Abstract

In two-dimensional (2D) materials, grain boundaries (GBs) often exhibit atomic structures and physical properties distinct from the basal plane, significantly impacting the overall properties of 2D films. Transition metal tellurides (TMTs), a subclass of transition metal dichalcogenides (TMDCs), display unique crystal structures and novel states, making them ideal for studying various physical phenomena. Despite the successful growth of centimeter-scale TMT films, limited research on GBs persists due to their high chemical reactivity and air sensitivity, which complicates atomic-scale investigations. In this review, we first introduce the fundamental crystal structure and physical properties of TMTs. We then summarize the growth methods for large-area TMT films and review the latest advances in understanding the atomic and electronic structures of GBs in TMT films grown by molecular beam epitaxy (MBE) and chemical vapor deposition (CVD), as revealed by scanning transmission electron microscopy (STEM) and scanning tunneling microscopy (STM). Finally, we discuss the challenges encountered in studying the atomic structures and properties of GBs in TMT films, and explore the potential applications of this research in the growth of single-crystal TMT films and future topological electronic devices. This review aims to draw attention to the challenges in researching GB structures and properties in TMTs, present the latest findings in the field, and foster further development in this area.