Wafer-scale synthesis of transition metal dichalcogenides and van der Waals heterojunctions

Two-dimensional materials, as a promising class of emerging materials, are expected to overcome the technical bottlenecks of silicon-based device miniaturization and enable the continuation of 'Moore's Law' due to their unique physical and chemical properties. Notably, transition metal dichalcogenides (TMDs) and heterojunctions have demonstrated unprecedented potential applications in novel electronic and optoelectronic devices. In recent years, breakthroughs have been continuously made in the preparation techniques and growth strategies of wafer-scale TMDs and heterostructures. Therefore, it is essential to systematically and comprehensively summarize the latest progress in wafer-scale synthesis. In this article, the preparation techniques and strategies of wafer-scale TMDs and heterojunctions are classified and summarized. Firstly, various wafer-scale synthesis techniques are described and the advantages and disadvantages of each technique in wafer-level preparation are compared. On this basis, the synthesis strategies derived from chemical vapor deposition are introduced and discussed comprehensively. Finally, we discuss the challenges and prospects associated with the preparation of wafer-scale materials and propose some feasible solutions.