Rhenium dichalcogenides (ReX2, X = S or Se): an emerging class of TMDs family
The two-dimensional transition metal dichalcogenides (TMDs) have been attracting increasing interest due to their unique structures and remarkable properties. As a new member of the TMDs family, rhenium dichalcogenides (ReX2, X = S or Se) possess many distinctive features because of an unusually distorted octahedral (1T) crystal structure with triclinic symmetry. In this unique crystal structure, each monolayer contains diamond-shaped chains (DS-chains) comprising interlinked Re4 clusters, which makes the structure anisotropic. This novel structure renders ReX2 with wide applications in (opto-)electronics, such as photodetectors and field effect transistors (FETs). ReX2 are new materials, so this review presents mainly basic and research work done in recent years. In the first part, the unique crystal and electronic structures are introduced. The second part summarizes the various growth methods for ReX2. Finally, the third part focuses on the applications in high-performance photodetectors and FETs based on 2D ReX2.