Matthew Panthani1
Iowa State University1
We present our recent efforts in synthesizing 2D Group IV nanosheets derived from layered Zintl phases. This presentation will focus on synthesis of layered/2D silicon (often referred to as silicane, siloxene, or layered polysilanes), as well as other 2D Group IV (comprised of Ge, and Si<sub>X</sub>Ge<sub>1-X</sub>)<sup>1,2</sup> nanosheets, with precise control over their size and surface chemistry. Using NMR, IR spectroscopy, and atomic pair distribution function analysis we gain insight in their local coordination and long-range order. The optical properties of the nanosheets are sensitive to the structure and interfacial chemistry, which we explain using DFT simulations of electronic band structures. Using ultrafast spectroscopy, we find evidence of a "fast" (few ns) optical transition in 2D Si nanosheets, with a temperature dependence may imply that we observve direct bandgap photoluminescence. Finally, we show the thermal stability of 2D silicon nanosheets, demonstrating their structure and photoluminescence are stable to temperatures beyond what they would experience in real applications.<br/><br/><u>References</u><br/>[1] Ryan et al, "Silicene, siloxene, or silicane? Revealing the structure and optical properties of silicon nanosheets derived from calcium disilicide." (2020) <i>Chemistry of Materials</i> 32(2), 795-804.<br/>[2] Ryan, Roling, Panthani. "Anisotropic Disorder and Thermal Stability of Silicane."(2021) <i>ACS Nano</i> 15(9),14557-14569.