@article{13334,
  keywords = {Mechanical Engineering, Condensed Matter Physics, General Materials Science, General Chemistry, Bioengineering},
  author = {Brendan McBennett and Albert Beardo and Emma Nelson and Begoña Abad and Travis Frazer and Amitava Adak and Yuka Esashi and Baowen Li and Henry Kapteyn and Margaret Murnane and Joshua Knobloch},
  title = {Universal Behavior of Highly Confined Heat Flow in Semiconductor Nanosystems: From Nanomeshes to Metalattices},
  abstract = {<p>Nanostructuring on length scales corresponding to phonon mean free paths provides control over heat flow in semiconductors and makes it possible to engineer their thermal properties. However, the influence of boundaries limits the validity of bulk models, while first-principles calculations are too computationally expensive to model real devices. Here we use extreme ultraviolet beams to study phonon transport dynamics in a 3D nanostructured silicon&nbsp;<i>metalattice</i>&nbsp;with deep nanoscale feature size and observe dramatically reduced thermal conductivity relative to bulk. To explain this behavior, we develop a predictive theory wherein thermal conduction separates into a geometric&nbsp;<i>permeability</i>&nbsp;component and an intrinsic&nbsp;<i>viscous</i>&nbsp;contribution, arising from a new and universal effect of nanoscale confinement on phonon flow. Using experiments and atomistic simulations, we show that our theory applies to a general set of highly confined silicon nanosystems, from metalattices, nanomeshes, porous nanowires, to nanowire networks, of great interest for next-generation energy-efficient devices.</p>
},
  year = {2023},
  journal = {Nano Letters},
  volume = {23},
  pages = {2129-2136},
  month = {2023-03},
  publisher = {American Chemical Society (ACS)},
  issn = {1530-6984, 1530-6992},
  doi = {10.1021/acs.nanolett.2c04419},
}