Tuesday, February 18, 20203:30 PM - 4:30 PMCNLS Conference Room (TA-3, Bldg 1690)|
Strain and Defect Induced Phenomena in van der Waals Materials: WSe2 and Te
Dr. Michael T. Pettes Materials Physics & Applications Division, Los Alamos National Laboratory
Control over disorder arising from nonequilibrium of atomic positions and distributions of mass offers a promising route to design nanomaterial properties for integration into a wide range of existing and future applications. In this talk, I will discuss our recent results on three areas where atomic-scale non-equilibrium and disorder can bring about profound enhancements in both physical and chemical properties, and preview the new imaging techniques that we are developing to establish atomic-level structure-transport property relationships in individual nanomaterials through in-situ transmission electron microscopy. Specific topics include our method to create deterministic single photon emission sites in epitaxial WSe2, our discovery of the isotope effect in purified 186W80Se2 which is the first report of isotope engineering in a two-dimensional transition metal dichalcogenide (TMD), and structural characterization by large data sets collected using electron microscopy with patterned probes including our observation of strain related torsion in one-dimensional tellurium. These capabilities and discoveries have general implications to defect engineering in the large family of two-dimensional materials and their and hence impact varied and promising technological areas from quantum communication to energy storage and conversion.
Host: Galen Craven