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Universal heat flow behavior in highly-confined semiconductor nanosystems

ORAL

Abstract

Nanostructured semiconductors can exhibit thermal properties unachievable in bulk systems, and will play a crucial role in next-generation nanoelectronics and energy efficient devices. However, first principles models are too computationally challenging for 3D nanostructured geometries, while mechanistic approaches make overly-simplistic assumptions about the nature of phonon-boundary interactions. Here, we study heat flow in a 3D nanostructured silicon metalattice, using an infrared pump laser to excite the sample and an extreme ultraviolet probe to monitor its relaxation. Analyzing surface acoustic waves launched by laser-excited metallic gratings, we first nondestructively extract porosity and elastic properties, and validate using electron tomography images [1]. We then model the heat flow dynamics, which obey a Fourier-like relation with an ultra-low apparent thermal conductivity. Through an analogy to rarefied gas flow in porous media, we explain this and similar measurements of phonon transport in silicon nanomeshes, porous nanowires and nanowire networks [2]. We isolate a geometry-dependent permeability contribution to thermal conduction from an intrinsic viscous component, which scales universally with porosity across all systems where feature sizes are much smaller than the dominant phonon mean free paths. This leads to an analytic description of thermal conduction in highly-confined silicon nanosystems, enabling their representation as effective media for engineering design applications.



[1] ACS AMI 14, 41316 (2022). [2] arXiv:2209.11743

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Publication: ACS AMI 14, 41316 (2022), arXiv:2209.11743

Presenters

  • Brendan G McBennett

    JILA

Authors

  • Brendan G McBennett

    JILA

  • Albert Beardo

    Department of Physics, JILA, and STROBE NSF Science & Technology Center, University of Colorado and NIST, Boulder, Colorado 80309, USA, University of Colorado, JILA, STROBE, JILA

  • Emma E Nelson

    Middlebury College

  • Charles S Bevis

    Department of Physics, JILA, and STROBE NSF Science & Technology Center, University of Colorado and NIST, Boulder, Colorado 80309, USA

  • Sadegh Yazdi

    Renewable and Sustainable Energy Institute and the Materials Science & Engineering Program, University of Colorado, Boulder, Colorado 80309, USA

  • Begoña Abad

    University of Basel

  • Travis D Frazer

    Argonne National Laboratory

  • Jorge Nicolas Hernandez Charpak

    American Physical Society

  • AMITAVA ADAK

    IIT (ISM)

  • Yuka Esashi

    University of Colorado, Boulder

  • Hiu Y Cheng

    Department of Chemistry and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA

  • Alex J Grede

    Department of Chemistry and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA

  • Pratibha Mahale

    Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA

  • Nabila N Nova

    Department of Chemistry and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA

  • Noel C Giebink

    Pennsylvania State University

  • Thomas E Mallouk

    Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA

  • John V Badding

    Department of Chemistry and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA

  • Baowen Li

    University of Colorado Boulder

  • Henry C Kapteyn

    University of Colorado, Boulder, University of Colorado, JILA, University of Colorado, Boulder

  • Margaret M Murnane

    JILA, JILA, University of Colorado, Boulder

  • Joshua L Knobloch

    University of Colorado, Boulder