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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 future materials and devices. 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, I will discuss three key synthesis challenges for realizing atomically engineered thin films and superlattices with atomically thin TMDs. Firstly, I will discuss how high-performance monolayer TMD films can be synthesized with wafer-scale uniformity. Furthermore, I 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, I will discuss how various TMD monolayers can be stacked vertically to form superlattices with designed properties. These scalable synthesis capabilities will further enable novel atomically engineered materials that hold great potential for future ultrathin electronics.
Saien Xie earned his B.S. in Mathematics and Physics at Tsinghua University and his Ph.D. in Applied Physics at Cornell University. His graduate work with Prof. Jiwoong Park focused on the synthesis and characterization of atomically thin van der Waals materials and their devices. He is currently a Kavli Postdoctoral Fellow in the Kavli Institute at Cornell for Nanoscale Science, where he works in the groups of Profs. Darrell Schlom and Kyle Shen on the synthesis of complex oxides and angle-resolved photoemission spectroscopy (ARPES). His work has been recognized by a number of awards including Kavli Postdoctoral Fellowship, the Materials Research Society Graduate Student Gold Award, and the William Nichols Findley Award for Exceptional Research.