title: Excellent Thermoelectric Properties in monolayer WSe2Nanoribbons due to Ultralow Phonon Thermal Conductivity.
abstract: By using first-principles calculations combined with the nonequilibrium Green's function method and phonon Boltzmann transport equation, we systematically investigate the influence of chirality, temperature and size on the thermoelectric properties of monolayer WSe2nanoribbons. The results show that the armchair WSe2nanoribbons have much higher ZT values than zigzag WSe2nanoribbons. The ZT values of armchair WSe2nanoribbons can reach 1.4 at room temperature, which is about seven times greater than that of zigzag WSe2nanoribbons. We also find that the ZT values of WSe2nanoribbons increase first and then decrease with the increase of temperature, and reach a maximum value of 2.14 at temperature of 500 K. It is because the total thermal conductance reaches the minimum value at 500 K. Moreover, the impact of width on the thermoelectric properties in WSe2nanoribbons is not obvious, the overall trend of ZT value decreases lightly with the increasing temperature. This trend of ZT value originates from the almost constant power factor and growing phonon thermal conductance.
authors.affiliation: Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha 410082, China.
authors.forename: Jue
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha 410082, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Xie
authors.affiliation: Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha 410082, China.
authors.forename: Xuan-Hao
authors.initials: XH
authors.lastname: Cao
authors.affiliation: Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha 410082, China.
authors.forename: Si-Cong
authors.initials: SC
authors.lastname: An
authors.affiliation: Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha 410082, China.|Hunan Province Higher Education Key Laboratory of Modeling and Monitoring on the Near-Earth Electromagnetic Environments, Changsha University of Science and Technology, Changsha 410004, China.
authors.forename: Wu-Xing
authors.initials: WX
authors.lastname: Zhou
authors.affiliation: Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha 410082, China.
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Tang
authors.affiliation: Department of Applied Physics, School of Physics and Electronics, Hunan University, Changsha 410082, China.
authors.forename: Ke-Qiu
authors.initials: KQ
authors.lastname: Chen