TY - GEN
T1 - A first-principles study of phonon transport properties of monolayer MoSe2
AU - Yan, Zhequan
AU - Yoon, Mina
AU - Kumar, Satish
N1 - Publisher Copyright:
© 2017 IEEE.
PY - 2017/7/25
Y1 - 2017/7/25
N2 - MoSe2 as one of the promising two-dimensional transition metal dichalcogenides (TMDCs) recently emerged as promising alternative of graphene for nano-electronic and opto-electronic devices. However, the heat removal is a critical issue for devices using two-dimensional (2D) materials, and low thermal conductivity of monolayer MoSe2 can significantly affect the performance and reliability of electronic devices. In this study, we use the density functional theory (DFT) and the phonon Boltzmann transport equation (BTE) to study the phonon transport properties of monolayer MoSe2 and compared the results with MoS2. The iterative solution of the BTE is used to predict the thermal conductivity of MoSe2, which is compared with the relaxation time approximation. Model for considering effect of sample size and defects are developed for monolayer MoSe2. Our results show the impact of sample size, Se vacancies, boundary and anharmonic phonon scattering on the thermal conductivity of MoSe2. Defect model is built based on the phonon scattering caused by the missing atom mass and the change of force constants between the under-coordinated atoms near the vacancies. Results indicate that the presence of 1%, 2% and 4% Se vacancies decrease the thermal conductivity of monolayer MoSe2 by 11.2%, 23.4% and 46.2% at room temperature. The results from this work will help in understanding the mechanism of phonon transport in 2D materials and provide insights for the future design of MoSe2-based electronics.
AB - MoSe2 as one of the promising two-dimensional transition metal dichalcogenides (TMDCs) recently emerged as promising alternative of graphene for nano-electronic and opto-electronic devices. However, the heat removal is a critical issue for devices using two-dimensional (2D) materials, and low thermal conductivity of monolayer MoSe2 can significantly affect the performance and reliability of electronic devices. In this study, we use the density functional theory (DFT) and the phonon Boltzmann transport equation (BTE) to study the phonon transport properties of monolayer MoSe2 and compared the results with MoS2. The iterative solution of the BTE is used to predict the thermal conductivity of MoSe2, which is compared with the relaxation time approximation. Model for considering effect of sample size and defects are developed for monolayer MoSe2. Our results show the impact of sample size, Se vacancies, boundary and anharmonic phonon scattering on the thermal conductivity of MoSe2. Defect model is built based on the phonon scattering caused by the missing atom mass and the change of force constants between the under-coordinated atoms near the vacancies. Results indicate that the presence of 1%, 2% and 4% Se vacancies decrease the thermal conductivity of monolayer MoSe2 by 11.2%, 23.4% and 46.2% at room temperature. The results from this work will help in understanding the mechanism of phonon transport in 2D materials and provide insights for the future design of MoSe2-based electronics.
KW - Boltzmann transport equation
KW - Defects
KW - Density functional theory
KW - MoSe
KW - Phonon transport
KW - Sample size effect
KW - Thermal conductivity
UR - http://www.scopus.com/inward/record.url?scp=85034452760&partnerID=8YFLogxK
U2 - 10.1109/ITHERM.2017.7992464
DO - 10.1109/ITHERM.2017.7992464
M3 - Conference contribution
AN - SCOPUS:85034452760
T3 - Proceedings of the 16th InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems, ITherm 2017
SP - 143
EP - 148
BT - Proceedings of the 16th InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems, ITherm 2017
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 16th IEEE InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems, ITherm 2017
Y2 - 30 May 2017 through 2 June 2017
ER -