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Title: Quasi-Ballistic Thermal Transport Across MoS2 Thin Films

Abstract

Layered two-dimensional (2D) materials have highly anisotropic thermal properties between the in-plane and cross-plane directions. Conventionally, it is thought that cross-plane thermal conductivities (κz) are low, and therefore c-axis phonon mean free paths (MFPs) are small. Here, we measure κz across MoS2 films of varying thickness (20–240 nm) and uncover evidence of very long c-axis phonon MFPs at room temperature in these layered semiconductors. Experimental data obtained using time-domain thermoreflectance (TDTR) are in good agreement with first-principles density functional theory (DFT). These calculations suggest that ~50% of the heat is carried by phonons with MFP > 200 nm, exceeding kinetic theory estimates by nearly 2 orders of magnitude. Because of quasi-ballistic effects, the κz of nanometer-thin films of MoS2 scales with their thickness and the volumetric thermal resistance asymptotes to a nonzero value, ~10 m2 K GW–1. This contributes as much as 30% to the total thermal resistance of a 20 nm thick film, the rest being limited by thermal interface resistance with the SiO2 substrate and top-side aluminum transducer. Furthermore, these findings are essential for understanding heat flow across nanometer-thin films of MoS2 for optoelectronic and thermoelectric applications.

Authors:
ORCiD logo [1];  [2]; ORCiD logo [3];  [4];  [5];  [4]; ORCiD logo [1]; ORCiD logo [6];  [4]; ORCiD logo [4]
  1. Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
  2. Univ. of Pittsburgh, Pittsburgh, PA (United States)
  3. Univ. of California, Davis, CA (United States)
  4. Stanford Univ., Stanford, CA (United States)
  5. Stanford Univ., Stanford, CA (United States); Northrop Grumman Corp., Redondo Beach, CA (United States)
  6. Univ. of California, Davis, CA (United States); Ikerbasque, Bilbao (Spain)
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
OSTI Identifier:
1529115
Grant/Contract Number:  
1542883; FA9550-14-1-0251; EEC-1449548; AC02-76SF00515
Resource Type:
Accepted Manuscript
Journal Name:
Nano Letters
Additional Journal Information:
Journal Volume: 19; Journal Issue: 4; Journal ID: ISSN 1530-6984
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; phonon; mean free path; MoS2; cross-plane; thermal conductivity; time-domain thermoreflectance

Citation Formats

Sood, Aditya, Xiong, Feng, Chen, Shunda, Cheaito, Ramez, Lian, Feifei, Asheghi, Mehdi, Cui, Yi, Donadio, Davide, Goodson, Kenneth E., and Pop, Eric. Quasi-Ballistic Thermal Transport Across MoS2 Thin Films. United States: N. p., 2019. Web. https://doi.org/10.1021/acs.nanolett.8b05174.
Sood, Aditya, Xiong, Feng, Chen, Shunda, Cheaito, Ramez, Lian, Feifei, Asheghi, Mehdi, Cui, Yi, Donadio, Davide, Goodson, Kenneth E., & Pop, Eric. Quasi-Ballistic Thermal Transport Across MoS2 Thin Films. United States. https://doi.org/10.1021/acs.nanolett.8b05174
Sood, Aditya, Xiong, Feng, Chen, Shunda, Cheaito, Ramez, Lian, Feifei, Asheghi, Mehdi, Cui, Yi, Donadio, Davide, Goodson, Kenneth E., and Pop, Eric. Wed . "Quasi-Ballistic Thermal Transport Across MoS2 Thin Films". United States. https://doi.org/10.1021/acs.nanolett.8b05174. https://www.osti.gov/servlets/purl/1529115.
@article{osti_1529115,
title = {Quasi-Ballistic Thermal Transport Across MoS2 Thin Films},
author = {Sood, Aditya and Xiong, Feng and Chen, Shunda and Cheaito, Ramez and Lian, Feifei and Asheghi, Mehdi and Cui, Yi and Donadio, Davide and Goodson, Kenneth E. and Pop, Eric},
abstractNote = {Layered two-dimensional (2D) materials have highly anisotropic thermal properties between the in-plane and cross-plane directions. Conventionally, it is thought that cross-plane thermal conductivities (κz) are low, and therefore c-axis phonon mean free paths (MFPs) are small. Here, we measure κz across MoS2 films of varying thickness (20–240 nm) and uncover evidence of very long c-axis phonon MFPs at room temperature in these layered semiconductors. Experimental data obtained using time-domain thermoreflectance (TDTR) are in good agreement with first-principles density functional theory (DFT). These calculations suggest that ~50% of the heat is carried by phonons with MFP > 200 nm, exceeding kinetic theory estimates by nearly 2 orders of magnitude. Because of quasi-ballistic effects, the κz of nanometer-thin films of MoS2 scales with their thickness and the volumetric thermal resistance asymptotes to a nonzero value, ~10 m2 K GW–1. This contributes as much as 30% to the total thermal resistance of a 20 nm thick film, the rest being limited by thermal interface resistance with the SiO2 substrate and top-side aluminum transducer. Furthermore, these findings are essential for understanding heat flow across nanometer-thin films of MoS2 for optoelectronic and thermoelectric applications.},
doi = {10.1021/acs.nanolett.8b05174},
journal = {Nano Letters},
number = 4,
volume = 19,
place = {United States},
year = {2019},
month = {2}
}

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Works referenced in this record:

Pulse accumulation, radial heat conduction, and anisotropic thermal conductivity in pump-probe transient thermoreflectance
journal, November 2008

  • Schmidt, Aaron J.; Chen, Xiaoyuan; Chen, Gang
  • Review of Scientific Instruments, Vol. 79, Issue 11
  • DOI: 10.1063/1.3006335

Heat capacity and thermal conductivity of hexagonal pyrolytic boron nitride
journal, May 1976


Measurement of the anisotropic thermal conductivity of molybdenum disulfide by the time-resolved magneto-optic Kerr effect
journal, December 2014

  • Liu, Jun; Choi, Gyung-Min; Cahill, David G.
  • Journal of Applied Physics, Vol. 116, Issue 23
  • DOI: 10.1063/1.4904513

Two-Dimensional Materials for Thermal Management Applications
journal, March 2018


S2DS: Physics-based compact model for circuit simulation of two-dimensional semiconductor devices including non-idealities
journal, December 2016

  • Suryavanshi, Saurabh V.; Pop, Eric
  • Journal of Applied Physics, Vol. 120, Issue 22
  • DOI: 10.1063/1.4971404

Role of Joule Heating on Current Saturation and Transient Behavior of Graphene Transistors
journal, February 2013

  • Islam, Sharnali; Li, Zuanyi; Dorgan, Vincent E.
  • IEEE Electron Device Letters, Vol. 34, Issue 2
  • DOI: 10.1109/LED.2012.2230393

Energy Dissipation in Monolayer MoS 2 Electronics
journal, May 2017


Temperature-Dependent Thermal Boundary Conductance of Monolayer MoS 2 by Raman Thermometry
journal, November 2017

  • Yalon, Eilam; Aslan, Özgür Burak; Smithe, Kirby K. H.
  • ACS Applied Materials & Interfaces, Vol. 9, Issue 49
  • DOI: 10.1021/acsami.7b11641

Interfacial Thermal Transport in Monolayer MoS 2 - and Graphene-Based Devices
journal, July 2017

  • Yasaei, Poya; Foss, Cameron J.; Karis, Klas
  • Advanced Materials Interfaces, Vol. 4, Issue 17
  • DOI: 10.1002/admi.201700334

Thermal Conductance of the 2D MoS2/h-BN and graphene/h-BN Interfaces
journal, March 2017

  • Liu, Yi; Ong, Zhun-Yong; Wu, Jing
  • Scientific Reports, Vol. 7, Issue 1
  • DOI: 10.1038/srep43886

Interfacial thermal conductance between few to tens of layered-MoS2 and c-Si: Effect of MoS2 thickness
journal, January 2017


Screening and interlayer coupling in multilayer MoS2
journal, March 2013

  • Das, Saptarshi; Appenzeller, Joerg
  • physica status solidi (RRL) - Rapid Research Letters, Vol. 7, Issue 4, p. 268-273
  • DOI: 10.1002/pssr.201307015

Few-layer molybdenum disulfide transistors and circuits for high-speed flexible electronics
journal, October 2014

  • Cheng, Rui; Jiang, Shan; Chen, Yu
  • Nature Communications, Vol. 5, Issue 1
  • DOI: 10.1038/ncomms6143

Thermal and Electronic Properties of Exfoliated Metal Chalcogenides
journal, November 2010

  • Kim, Jong-Young; Choi, Soon-Mok; Seo, Won-Seon
  • Bulletin of the Korean Chemical Society, Vol. 31, Issue 11
  • DOI: 10.5012/bkcs.2010.31.11.3225

Thermal transport in van der Waals solids from first-principles calculations
journal, September 2016


Experimental evidence of very long intrinsic phonon mean free path along the c -axis of graphite
journal, January 2015

  • Fu, Qiang; Yang, Juekuan; Chen, Yunfei
  • Applied Physics Letters, Vol. 106, Issue 3
  • DOI: 10.1063/1.4906348

Temperature-Dependent Mean Free Path Spectra of Thermal Phonons Along the c -Axis of Graphite
journal, February 2016


Heat transport in silicon from first-principles calculations
journal, August 2011


Anisotropic and inhomogeneous thermal conduction in suspended thin-film polycrystalline diamond
journal, May 2016

  • Sood, Aditya; Cho, Jungwan; Hobart, Karl D.
  • Journal of Applied Physics, Vol. 119, Issue 17
  • DOI: 10.1063/1.4948335

Cross-plane thermal properties of transition metal dichalcogenides
journal, February 2013

  • Muratore, C.; Varshney, V.; Gengler, J. J.
  • Applied Physics Letters, Vol. 102, Issue 8
  • DOI: 10.1063/1.4793203

Direct Visualization of Thermal Conductivity Suppression Due to Enhanced Phonon Scattering Near Individual Grain Boundaries
journal, April 2018


Broadband phonon mean free path contributions to thermal conductivity measured using frequency domain thermoreflectance
journal, March 2013

  • Regner, Keith T.; Sellan, Daniel P.; Su, Zonghui
  • Nature Communications, Vol. 4, Issue 1
  • DOI: 10.1038/ncomms2630

Thermal Conductivity of Silicon from 300 to 1400°K
journal, June 1963


Specific heat of aluminum from zero to its melting temperature and beyond. Equation for representation of the specific heat of solids
journal, October 1970

  • Buyco, Edgar H.; Davis, Fred E.
  • Journal of Chemical & Engineering Data, Vol. 15, Issue 4
  • DOI: 10.1021/je60047a035

The heat capacity of pure silicon and germanium and properties of their vibrational frequency spectra
journal, March 1959


Thermal phonon boundary scattering in anisotropic thin films
journal, November 2015


Layer thickness-dependent phonon properties and thermal conductivity of MoS 2
journal, February 2016

  • Gu, Xiaokun; Li, Baowen; Yang, Ronggui
  • Journal of Applied Physics, Vol. 119, Issue 8
  • DOI: 10.1063/1.4942827

Crystalline coherence length effects on the thermal conductivity of MgO thin films
journal, August 2016

  • Meyer, Kelsey E.; Cheaito, Ramez; Paisley, Elizabeth
  • Journal of Materials Science, Vol. 51, Issue 23
  • DOI: 10.1007/s10853-016-0261-5

Anisotropic Thermal Conductivity of Exfoliated Black Phosphorus
journal, October 2015

  • Jang, Hyejin; Wood, Joshua D.; Ryder, Christopher R.
  • Advanced Materials, Vol. 27, Issue 48
  • DOI: 10.1002/adma.201503466

Nonmonotonic thickness-dependence of in-plane thermal conductivity of few-layered MoS 2 : 2.4 to 37.8 nm
journal, January 2018

  • Yuan, Pengyu; Wang, Ridong; Wang, Tianyu
  • Physical Chemistry Chemical Physics, Vol. 20, Issue 40
  • DOI: 10.1039/C8CP02858C

Frequency dependence of the thermal conductivity of semiconductor alloys
journal, August 2007


Two-channel model for nonequilibrium thermal transport in pump-probe experiments
journal, October 2013


Anisotropic failure of Fourier theory in time-domain thermoreflectance experiments
journal, October 2014

  • Wilson, R. B.; Cahill, David G.
  • Nature Communications, Vol. 5, Issue 1
  • DOI: 10.1038/ncomms6075

Nonlocal theory for heat transport at high frequencies
journal, November 2014


Interpretation of thermoreflectance measurements with a two-temperature model including non-surface heat deposition
journal, December 2015

  • Regner, K. T.; Wei, L. C.; Malen, J. A.
  • Journal of Applied Physics, Vol. 118, Issue 23
  • DOI: 10.1063/1.4937995

Temperature Dependence of Anisotropic Thermal-Conductivity Tensor of Bulk Black Phosphorus
journal, November 2016


Lattice dynamics of hexagonal Mo S 2 studied by neutron scattering
journal, July 1975


Tuning thermal conductivity in molybdenum disulfide by electrochemical intercalation
journal, October 2016

  • Zhu, Gaohua; Liu, Jun; Zheng, Qiye
  • Nature Communications, Vol. 7, Issue 1
  • DOI: 10.1038/ncomms13211

An electrochemical thermal transistor
journal, October 2018


Heat Conduction across Monolayer and Few-Layer Graphenes
journal, November 2010

  • Koh, Yee Kan; Bae, Myung-Ho; Cahill, David G.
  • Nano Letters, Vol. 10, Issue 11, p. 4363-4368
  • DOI: 10.1021/nl101790k

High Current Density and Low Thermal Conductivity of Atomically Thin Semimetallic WTe 2
journal, July 2016


QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials
journal, September 2009

  • Giannozzi, Paolo; Baroni, Stefano; Bonini, Nicola
  • Journal of Physics: Condensed Matter, Vol. 21, Issue 39, Article No. 395502
  • DOI: 10.1088/0953-8984/21/39/395502

Self-interaction correction to density-functional approximations for many-electron systems
journal, May 1981


Relativistic separable dual-space Gaussian pseudopotentials from H to Rn
journal, August 1998


Special points for Brillouin-zone integrations
journal, June 1976

  • Monkhorst, Hendrik J.; Pack, James D.
  • Physical Review B, Vol. 13, Issue 12, p. 5188-5192
  • DOI: 10.1103/PhysRevB.13.5188

Phonons and related crystal properties from density-functional perturbation theory
journal, July 2001

  • Baroni, Stefano; de Gironcoli, Stefano; Dal Corso, Andrea
  • Reviews of Modern Physics, Vol. 73, Issue 2
  • DOI: 10.1103/RevModPhys.73.515

ShengBTE: A solver of the Boltzmann transport equation for phonons
journal, June 2014

  • Li, Wu; Carrete, Jesús; A. Katcho, Nebil
  • Computer Physics Communications, Vol. 185, Issue 6
  • DOI: 10.1016/j.cpc.2014.02.015

    Works referencing / citing this record:

    Spatially resolved thermoreflectance techniques for thermal conductivity measurements from the nanoscale to the mesoscale
    journal, October 2019

    • Olson, David H.; Braun, Jeffrey L.; Hopkins, Patrick E.
    • Journal of Applied Physics, Vol. 126, Issue 15
    • DOI: 10.1063/1.5120310

    Ultrahigh thermal isolation across heterogeneously layered two-dimensional materials
    journal, August 2019

    • Vaziri, Sam; Yalon, Eilam; Muñoz Rojo, Miguel
    • Science Advances, Vol. 5, Issue 8
    • DOI: 10.1126/sciadv.aax1325