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Isotopic Effect of Carrier Relaxation in Graphene-hBN Heterostructures

ORAL

Abstract

In atomically thin systems, the choice of substrate plays an important role in the relaxation of photo-excited carriers. In previous work, hexagonal boron nitride (hBN) substrates have been shown to improve the thermal relaxation rates of carriers in graphene as compared to silicon oxide substrates. Naturally occurring boron contains a mixture of two isotopes with atomic masses 10 and 11 with abundances of 20% and 80% respectively. Theoretical studies have predicted a higher thermal conductivity with higher isotopic purity of hBN, due to reduced phonon scattering from isotopic defects. We utilize femtosecond pump-probe spectroscopy to observe the time dynamics of photo-excited carriers in graphene-hBN heterostructures for both natural and isotopically pure hBN and find faster relaxation in isotopically pure hbn substrates.

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Presenters

  • Song Liu

    Columbia University, Mechanical Engineering, Columbia, Department of Mechanical Engineering, Columbia University, Columbia Univ

Authors

  • Alexandra Brasington

    Physics, University of Arizona

  • Song Liu

    Columbia University, Mechanical Engineering, Columbia, Department of Mechanical Engineering, Columbia University, Columbia Univ

  • James Edgar

    Chemical Engineering, Kansas State University, Kansas State University, Tim Taylor Department of Chemical Engineering, Kansas State University

  • Takashi Taniguchi

    National Institute for Materials Science, National Institute for Materials Science, Japan, National Institure for Materials Science, Advanced Materials Laboratory, National Institute for Materials Science, NIMS, National Institute of Materials Science, National Institute for Materials Science (NIMS), International Center for Materials Nanoarchitectonics, National Institute for Materials Science, National Institute for Materials Science,1-1 Namiki, National Institute of Material Science, National Institute for Materials Science, Tsukuba, Japan, International Center for Materials Nanoarchitectonics, NIMS, Research Center for Functional Materials, National Institute for Materials Science, National Institute of Materials Science, Tsukuba, Japan, National Institude for Materials Science, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba 305-0044, Japan, International Center for Materials Nanoarchitectonics, National Institute for Materials, NIMS - Japan, National Institute for Materials Science ,Japan, National Institute for Materials Science, Tsukuba, 305-0044, Ibaraki, Japan, National Institute for Material Science, National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Material Science Japan, 8International Center for Materials Nanoarchitectonics, NIMS Tsukuba, National Institute for Materials Science: Namiki, Tsukuba, Ibaraki, JP, National Institue for Material Science, National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan, Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, Research Center for Functional Materials, National In, Research Center for Functional Materials, Japan, Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan, International Center for Material Nanoarchitectonics, National Institute for Materials Science, International Center for Materials Nanoarchitectonics, NIMS Suguba, NIMS, Tsukuba, Japan, National Cheng Kung University, National Institute for Materials Science, Namiki 1-1, Tsukuba, 305-0044, Ibaraki, Japan, National institute of material science, Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan, Advanced Materials Laboratory, NIMS, National Institute for Materials Science, International Center for Materials Nanoarchitectonics, National Institute of Material Science, Japan, Tsukuba, National Institute for Materials Science

  • Kenji Watanabe

    National Institute for Materials Science, National Institute for Materials Science, Japan, National Institure for Materials Science, Advanced Materials Laboratory, National Institute for Materials Science, NIMS, National Institute of Materials Science, National Institute for Materials Science (NIMS), Research Center for Functional Materials, National Institute for Materials Science, National Institute for Materials Science,1-1 Namiki, National Institute of Material Science, National Institute for Materials Science, Tsukuba, Japan, Research Center for Functional Materials, NIMS, National Institute of Materials Science, Tsukuba, Japan, National Institude for Materials Science, National Institute for Materials Science, Tsukuba, Ibaraki, Japan, Research Center for Functional Materials, National Institute for Materials Science, Tsukuba 305-0044, Japan, International Center for Materials Nanoarchitectonics, National Institute for Materials, NIMS - Japan, National Institute for Materials Science ,Japan, National Institute for Materials Science, Tsukuba, 305-0044, Ibaraki, Japan, National Institute for Material Science, National Institute for Material Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Material Science Japan, NIMS Tsukuba, National Institute for Materials Science, Research Center for Functional Materials, Japan, Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, National Institute for Materials Science: Namiki, Tsukuba, Ibaraki, JP, National Institue for Material Science, National Institute for Materials Science,1-1 Namiki, Tsukuba, 305-0044, Japan, Materials, NIMS, Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan, Research Center for Functional Materials, National In, Research Center for Functional Materials, Japan, International Center for Materials Nanoarchitectonics, National Institute for Materials Science, International Center for Materials nanoarchtectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan, NIMS Suguba, NIMS, Tsukuba, Japan, National Institute for Materials Science, Namiki 1-1, Tsukuba, 305-0044, Ibaraki, Japan, National institute of material science, Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan, Advanced Materials Laboratory, NIMS, Research Center for Functional Materials, National Institute for Materials Science, Ibaraki, Japan, National Institute for Materials Science, Research Center for Functional Materials, National Institute of Material Science, Japan, Tsukuba, National Institute for Materials Science

  • Arvinder S Sandhu

    Physics, University of Arizona

  • Brian J LeRoy

    Physics, University of Arizona, Department of Physics, University of Arizona, Physics, University of Arizona, Tucson AZ, University of Arizona