Research ArticleMATERIALS SCIENCE

High thermal conductivity of high-quality monolayer boron nitride and its thermal expansion

See allHide authors and affiliations

Science Advances  07 Jun 2019:
Vol. 5, no. 6, eaav0129
DOI: 10.1126/sciadv.aav0129
  • Fig. 1 The first-order temperature coefficients.

    (A) Optical image of a 1-2L BN on SiO2/Si substrate with prefabricated microwells. (B) AFM image of the squared area in (A). (C and D) Raman G bands of the 1L BN suspended over and bound to SiO2/Si at different heating stage temperatures from 293 to 403 K with an interval of 10 K. a.u., arbitrary units. (E) Summarized G band frequency changes of the suspended and substrate-bound 1-3L BN as a function of temperature and the corresponding linear fittings. (F) AFM height traces of the dash lines in (B). (G and H) Schematic diagrams of the thermal expansion of suspended and substrate-bound BN nanosheets.

  • Fig. 2 Laser power effect.

    Optical (A) and AFM (B) images of a 1L BN on Au/Si. The Raman G bands of the suspended (C) 1L BN, (D) 2L BN, and (E) 3L BN under different laser power. a.u., arbitrary units.

  • Fig. 3 Light absorbance of atomically thin BN.

    Optical images of a 1-2L BN as exfoliated on SiO2/Si (A) and transferred onto a Si3N4 TEM grid (B). (C) AFM image of the BN suspended over the TEM grid. (D) Laser absorbance of 1-3L BN and the corresponding linear fitting.

  • Fig. 4 Thermal conductivity of 1-3L BN.

    (A) Experimental κ of the suspended 1-3L BN as a function of temperature (filled circles) and the corresponding theoretical values at 300 K (open rhombus). (B) Temperature distribution of a suspended 1L BN over 3.8-μm microwells under laser heating up to 330 K with the heat sink kept at 298 K, and the dashed circle represents the edge of the suspended BN. (C) Comparison of the thermal conductivity of some common semiconductors and insulators.

  • Fig. 5 Phonon dispersion and Grüneisen parameters.

    (A to C) Phonon dispersion and (D to F) Grüneisen parameters of 1-3L BN calculated by DFT. The phonon branches are labeled for 1L BN. Dashed curves represent additional phonon branches and corresponding Grüneisen parameters due to additional BN layers.

  • Fig. 6 TECs of 1-3L BN.

    (A) The G band frequency shifts as a function of temperature and the corresponding fittings of 1-3L BN bound to SiO2/Si using TECs as fitting parameters. (B) Experimental (dots) and theoretical (lines) curves of the TECs of the 1-3L BN.

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/5/6/eaav0129/DC1

    Section S1. Optical and AFM images of atomically thin BN samples

    Section S2. Raman spectra of the suspended 1-3L and bulk BN

    Section S3. Temperature coefficients of the 1-3L BN suspended over Au/Si substrate

    Section S4. Absorbance of 1-3L BN measured on quartz

    Section S5. Laser beam radius

    Section S6. Error calculation

    Section S7. Thermal conductivity of graphene as a control

    Section S8. Thermal equilibration on MD simulations using LAMMPS

    Section S9. TEC of SiO2/Si substrate simulated by FEM

    Section S10. Comparison of the TEC of common 2D materials

    Fig. S1. Characterizations of additional 1-3L BN.

    Fig. S2. Raman G bands of 1-3L and bulk BN.

    Fig. S3. Raman G band shifts of 1-3L BN suspended over Au/Si and SiO2/Si as a function of temperature and the corresponding linear fittings.

    Fig. S4. Laser absorbance of atomically thin BN on quartz.

    Fig. S5. Transmitted optical intensity of 1L BN.

    Fig. S6. Raman mapping of Si and corresponding fitting.

    Fig. S7. The first-order temperature coefficient and thermal conductivity of graphene.

    Fig. S8. Temperature versus time step for 1L BN.

    Fig. S9. Strain distribution of SiO2/Si substrate.

    Table S1. TEC of 2D materials (10−6 K−1).

  • Supplementary Materials

    This PDF file includes:

    • Section S1. Optical and AFM images of atomically thin BN samples
    • Section S2. Raman spectra of the suspended 1-3L and bulk BN
    • Section S3. Temperature coefficients of the 1-3L BN suspended over Au/Si substrate
    • Section S4. Absorbance of 1-3L BN measured on quartz
    • Section S5. Laser beam radius
    • Section S6. Error calculation
    • Section S7. Thermal conductivity of graphene as a control
    • Section S8. Thermal equilibration on MD simulations using LAMMPS
    • Section S9. TEC of SiO2/Si substrate simulated by FEM
    • Section S10. Comparison of the TEC of common 2D materials
    • Fig. S1. Characterizations of additional 1-3L BN.
    • Fig. S2. Raman G bands of 1-3L and bulk BN.
    • Fig. S3. Raman G band shifts of 1-3L BN suspended over Au/Si and SiO2/Si as a function of temperature and the corresponding linear fittings.
    • Fig. S4. Laser absorbance of atomically thin BN on quartz.
    • Fig. S5. Transmitted optical intensity of 1L BN.
    • Fig. S6. Raman mapping of Si and corresponding fitting.
    • Fig. S7. The first-order temperature coefficient and thermal conductivity of graphene.
    • Fig. S8. Temperature versus time step for 1L BN.
    • Fig. S9. Strain distribution of SiO2/Si substrate.
    • Table S1. TEC of 2D materials (10−6 K−1).

    Download PDF

    Files in this Data Supplement:

Stay Connected to Science Advances

Navigate This Article