Janus 2D TMDs (Janus two-dimensional transition metal dichalcogenides) represent an innovative class of 2D materials composed of a single atomic layer in which the chalcogen atoms above and below the central metal layer are different, forming an asymmetric X–M–Y structure (where M is the transition metal, such as Mo or W, and X and Y are chalcogens like S, Se, or Te). This broken out-of-plane mirror symmetry induces an internal perpendicular electric field, resulting in unique properties such as piezoelectric polarization, pyroelectricity, and Rashba spin–orbit coupling, with promising applications in sensors, photodetectors, spintronic devices, and energy conversion systems. The synthesis of these structures involves the selective substitution of one chalcogen layer in conventional TMDs through processes such as controlled sulfurization or selenization, electron beam irradiation, or thermal treatment in reactive atmospheres (such as H2S). These transformations, often influenced by strain, also modulate optical and electronic properties, making Janus materials highly versatile for future applications in nanoelectronics and catalysis.
The main goals of the project include the successful fabrication of Janus 2D TMDs and the identification of their characteristic vibrational and optical signatures. The Raman and PL studies will provide key insights into how structural defects, chalcogen substitution, and thermal processing influence material quality. These findings will help advance the understanding of the physical properties and fabrication mechanisms of Janus TMDs.
