(662a) 2D Silicon, Germanium, and Other Group IV Semiconductors: Synthesis and Applications

Nanostructured semiconductors offer unique avenues due to their fundamentally different phase behavior, size- and surface-dependent properties, and relaxation of quantum mechanical selection rules. We present our recent developments in synthesizing 2D Group IV nanomaterials – atomically thin nanosheets comprised of Si, Ge, and/or Sn (and their alloys). We show that these nanomaterials have optical properties that can be tuned by modifying their composition, size, and surface chemistry. Using temperature-dependent spectroscopy, we show evidence of direct bandgap transitions, corroborated by electronic band structure simulations. We show new insight into the disorder and structural dynamics in Group IV nanomaterials using synchrotron-based x-ray scattering and neutron scattering experiments. Finally, we explore these materials' novel defect chemistry and phase behavior and show potential implications for application areas such as computing, sensing, telecommunications, and quantum information science. We will also show prelimary results for their use in multivalent calcium ion batteries.