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Title: Effect of Metal Doping and Vacancies on the Thermal Conductivity of Monolayer Molybdenum Diselenide

Abstract

It is well understood that defect engineering can give rise to exotic electronic properties in transition-metal dichalcogenides, but to this date, there is no detailed study to illustrate how defects can be engineered to tailor their thermal properties. Here, through combined experimental and theoretical approaches based on the first-principles density functional theory and Boltzmann transport equations, we have explored the effect of lattice vacancies and substitutional tungsten (W) doping on the thermal transport of the suspended molybdenum diselenide (MoSe2) monolayers grown by chemical vapor deposition (CVD). The results show that even though the isoelectronic substitution of the W atoms for Mo atoms in CVD-grown Mo 0.82W 018Se 2 monolayers reduces the Se vacancy concentration by 50% compared to that found in the MoSe2 monolayers, the thermal conductivity remains intact in a wide temperature range. On the other hand, Se vacancies have a detrimental effect for both samples and more so in the Mo 0.82W 018Se 2 monolayers, which results in thermal conductivity reduction up to 72% for a vacancy concentration of 4%. This is because the mass of the W atom is larger than that of the Mo atom, and missing a Se atom at a vacancy site results inmore » a larger mass difference and therefore kinetic energy and potential energy difference. Furthermore, the monotonically increasing thermal conductivity with temperature for both systems at low temperatures indicates the importance of boundary scattering over defects and phonon–phonon scattering at these temperatures.« less

Authors:
ORCiD logo [1];  [1]; ORCiD logo [2];  [3];  [4];  [4];  [2]; ORCiD logo [3]; ORCiD logo [3]; ORCiD logo [1]
  1. Univ. of Houston, TX (United States). Dept. of Mechanical Engineering
  2. G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30313, United States
  3. Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
  4. Univ. of Houston, TX (United States). Dept. of Physics and Texas Center for Superconductivity
Publication Date:
Research Org.:
Lawrence Berkeley National Laboratory-National Energy Research Scientific Computing Center; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1494884
Alternate Identifier(s):
OSTI ID: 1485121
Grant/Contract Number:  
AC02-05CH11231; AC05-00OR22725
Resource Type:
Accepted Manuscript
Journal Name:
ACS Applied Materials and Interfaces
Additional Journal Information:
Journal Volume: 10; Journal Issue: 5; Journal ID: ISSN 1944-8244
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 42 ENGINEERING; defect engineering; isoelectronic doping; molybdenum diselenide; thermal conductivity; transition-metal dichalcogenides; vacancy

Citation Formats

Yarali, Milad, Brahmi, Hatem, Yan, Zhequan, Li, Xufan, Xie, Lixin, Chen, Shuo, Kumar, Satish, Yoon, Mina, Xiao, Kai, and Mavrokefalos, Anastassios. Effect of Metal Doping and Vacancies on the Thermal Conductivity of Monolayer Molybdenum Diselenide. United States: N. p., 2018. Web. doi:10.1021/acsami.7b14310.
Yarali, Milad, Brahmi, Hatem, Yan, Zhequan, Li, Xufan, Xie, Lixin, Chen, Shuo, Kumar, Satish, Yoon, Mina, Xiao, Kai, & Mavrokefalos, Anastassios. Effect of Metal Doping and Vacancies on the Thermal Conductivity of Monolayer Molybdenum Diselenide. United States. doi:10.1021/acsami.7b14310.
Yarali, Milad, Brahmi, Hatem, Yan, Zhequan, Li, Xufan, Xie, Lixin, Chen, Shuo, Kumar, Satish, Yoon, Mina, Xiao, Kai, and Mavrokefalos, Anastassios. Tue . "Effect of Metal Doping and Vacancies on the Thermal Conductivity of Monolayer Molybdenum Diselenide". United States. doi:10.1021/acsami.7b14310. https://www.osti.gov/servlets/purl/1494884.
@article{osti_1494884,
title = {Effect of Metal Doping and Vacancies on the Thermal Conductivity of Monolayer Molybdenum Diselenide},
author = {Yarali, Milad and Brahmi, Hatem and Yan, Zhequan and Li, Xufan and Xie, Lixin and Chen, Shuo and Kumar, Satish and Yoon, Mina and Xiao, Kai and Mavrokefalos, Anastassios},
abstractNote = {It is well understood that defect engineering can give rise to exotic electronic properties in transition-metal dichalcogenides, but to this date, there is no detailed study to illustrate how defects can be engineered to tailor their thermal properties. Here, through combined experimental and theoretical approaches based on the first-principles density functional theory and Boltzmann transport equations, we have explored the effect of lattice vacancies and substitutional tungsten (W) doping on the thermal transport of the suspended molybdenum diselenide (MoSe2) monolayers grown by chemical vapor deposition (CVD). The results show that even though the isoelectronic substitution of the W atoms for Mo atoms in CVD-grown Mo0.82W018Se2 monolayers reduces the Se vacancy concentration by 50% compared to that found in the MoSe2 monolayers, the thermal conductivity remains intact in a wide temperature range. On the other hand, Se vacancies have a detrimental effect for both samples and more so in the Mo0.82W018Se2 monolayers, which results in thermal conductivity reduction up to 72% for a vacancy concentration of 4%. This is because the mass of the W atom is larger than that of the Mo atom, and missing a Se atom at a vacancy site results in a larger mass difference and therefore kinetic energy and potential energy difference. Furthermore, the monotonically increasing thermal conductivity with temperature for both systems at low temperatures indicates the importance of boundary scattering over defects and phonon–phonon scattering at these temperatures.},
doi = {10.1021/acsami.7b14310},
journal = {ACS Applied Materials and Interfaces},
number = 5,
volume = 10,
place = {United States},
year = {2018},
month = {1}
}

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