Phonon interaction with ripples and defects in thin layered molybdenum disulfide
- University of Texas at Austin, TX (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Compared to other extrinsic phonon scattering mechanisms such as surface and interior defects, phonon scattering and lattice thermal resistance due to structural rippling in few-layer two-dimensional (2D) materials are under-examined. Here, the temperature-dependent basal-plane thermal conductivities (κ) of one rippled and four flat molybdenum disulfide (MoS2) samples are measured using a four-probe thermal transport measurement method. A flat 18 nm thick sample and a rippled 20 nm thick sample show similar peak κ values of 122 ± 17 and 129 ± 19 W m–1 K–1, respectively. In comparison, a 32 nm thick flat sample has a peak κ value of only 58 ± 11 W m–1 K–1 despite having an increased thickness. The peak thermal conductivities of the five samples decrease with increasing integrated Raman intensity caused by defects in the frequency range of the phonon bandgap in MoS2. In conjunction with the experimental findings, theoretical calculations of the temperature-, thickness-, strain-, and defect-dependent κ of thin MoS2 layers reveal the importance of interior defect scattering over scattering from compression-induced ripples and surface defects in these samples. Furthermore, the results further clarify the conditions where ripples are important in determining the basal plane thermal resistance in layered systems.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Texas at Austin, TX (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE)
- Grant/Contract Number:
- AC05-00OR22725; FG02-07ER46377
- OSTI ID:
- 1524885
- Alternate ID(s):
- OSTI ID: 1854547; OSTI ID: 1996992
- Journal Information:
- Applied Physics Letters, Vol. 114, Issue 22; ISSN 0003-6951
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Thermoelectric measurements of high-resistance Janus monolayer transition-metal dichalcogenide
|
journal | October 2019 |
Similar Records
Basal-plane thermal conductivity of few-layer molybdenum disulfide
Basal-plane thermal conductivity of nanocrystalline and amorphized thin germanane