Atomic Structures and Electronic Properties of Carbide Surfaces Unraveled by Scanning Tunneling Microscopy

Carbides, especially transition metal carbides (TMCs) and non-metallic silicon carbides (SiCs), have registered wide applications in catalysis, superconductivity, semiconductor, and the like. Systematic studies have demonstrated the essential role of carbon in finetuning the atomic structures and electronic properties of carbides to improve their catalytic performance, superconducting transition temperature, and semiconductor bandgap. These advancements have positioned carbides as efficient substitutes for noble metals and crucial components in technological innovations. Scanning tunneling microscopy (STM) has emerged as a powerful technique in these studies, providing high-resolution visualization and mapping of the surface geometric and electronic structures of these functionalized carbides. This review mainly focuses on the key aspects like the structures and properties of the aforementioned TMC and SiC surfaces unraveled by STM, aiming at understanding the fundamentals behind the state-of-the-art technologies and advanced applications of the carbide-involved functional systems. A very brief perspective on this topic is also provided at the end. Studies have demonstrated the essential role of carbon in modifying the atomic structures and electronic properties of carbides to improve their catalytic performance, superconducting transition temperature, and semiconductor bandgap. Scanning tunneling microscopy has emerged as a powerful tool in these carbide studies, providing high-resolution visualization of their topographic structures and subtle mapping of their electronic structures on the atomic scale. image