Thin film materials and heterostructures play a key role in modern technology including electronics and photonics. Atomically precise engineering of thin film materials enables unprecedented control of their structure and properties, bringing exciting opportunities to materials science. Transition metal dichalcogenides (TMDs), which form three-atom-thick monolayers with van der Waals surfaces, provide an ideal material platform with diverse electrical and optical properties for thin film engineering in the atomically thin limit.

In this talk, Dr. Xie will discuss three key synthesis challenges for realizing atomically engineered thin films and superlattices with atomically thin TMDs. Firstly, he will discuss how high-performance monolayer TMD films can be synthesized with wafer-scale uniformity. Furthermore, he will discuss how dissimilar TMDs (e.g. tungsten disulfide and tungsten diselenide) can be integrated laterally in the monolayer plane to form superlattices without dislocations, despite a large 4% lattice mismatch. Lastly, Dr. Xie will discuss how various TMD monolayers can be stacked vertically to form programmed van der Waals superlattices. These scalable synthesis capabilities will further enable novel atomically engineered materials that hold great potential for future ultrathin electronics.