2D-MoS 2 goes 3D: transferring optoelectronic properties of 2D MoS 2 to a large-area thin film

The ongoing miniaturization of electronic devices has boosted the development of new post-silicon two-dimensional (2D) semiconductors, such as transition metal dichalcogenides, one of the most prominent materials being molybdenum disulfide (MoS 2 ). A major obstacle for the industrial production of MoS 2 -based devices lies in the growth techniques. These must ensure the reliable fabrication of MoS 2 with tailored 2D properties to allow for the typical direct bandgap of 1.9 eV, while maintaining large-area growth and device compatibility. In this work, we used a versatile and industrially scalable MoS 2 growth method based on ionized jet deposition and annealing at 250 °C, through which a 3D stable and scalable material exhibiting excellent electronic and optical properties of 2D MoS 2 is synthesized. The thickness-related limit, i.e., the desired optical and electronic properties being limited to 2D single/few-layered MoS 2 , was overcome in the thin film through the formation of encapsulated highly crystalline 2D MoS 2 nanosheets exhibiting a bandgap of 1.9 eV and sharp optical emission. The newly synthesized 2D-in-3D MoS 2 structure will facilitate device compatibility of 2D materials and confer superior optoelectronic device function.