Janus 2D transition metal chalcogenides have gained considerable attention for various applications due to the structural asymmetry and distinct properties. This review presents an overview of current theoretical and experimental progress in the development of Janus 2D transition metal chalcogenides. The challenges and future prospects for the further development of Janus 2D materials are also discussed. Abstract Since the discovery of graphene, 2D materials with various properties have gained increasing attention in fields such as novel electronic, optic, spintronic, and valleytronic devices. As an important derivative of 2D materials, Janus 2D materials, such as Janus transition metal chalcogenides (TMDs), have become a research hot spot in recent years. Janus 2D materials with mirror asymmetry display novel properties, such as the Rashba effect and normal piezoelectric polarization, providing great promise for their application in sensors, actuators, and other electromechanical devices. Here, the current theoretical and experimental progresses made in the development of Janus 2D TMDs, including their structure and stability, electronic properties, fabrication, and the results of their characterization are reported. Finally, the future prospects for the further development of Janus 2D materials are considered.

Published in: "Small".