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Pàgina inicial > Articles > Articles publicats > Unraveling heat transport and dissipation in suspended MoSe2 from bulk to monolayer |
Data: | 2022 |
Resum: | Understanding heat flow in layered transition metal dichalcogenide (TMD) crystals is crucial for applications exploiting these materials. Despite significant efforts, several basic thermal transport properties of TMDs are currently not well understood, in particular how transport is affected by material thickness and the material's environment. This combined experimental-theoretical study establishes a unifying physical picture of the intrinsic lattice thermal conductivity of the representative TMD MoSe. Thermal conductivity measurements using Raman thermometry on a large set of clean, crystalline, suspended crystals with systematically varied thickness are combined with ab initio simulations with phonons at finite temperature. The results show that phonon dispersions and lifetimes change strongly with thickness, yet the thinnest TMD films exhibit an in-plane thermal conductivity that is only marginally smaller than that of bulk crystals. This is the result of compensating phonon contributions, in particular heat-carrying modes around ≈0. 1 THz in (sub)nanometer thin films, with a surprisingly long mean free path of several micrometers. This behavior arises directly from the layered nature of the material. Furthermore, out-of-plane heat dissipation to air molecules is remarkably efficient, in particular for the thinnest crystals, increasing the apparent thermal conductivity of monolayer MoSe by an order of magnitude. These results are crucial for the design of (flexible) TMD-based (opto-)electronic applications. |
Ajuts: | European Commission 824143 European Commission 814487 European Commission 804349 European Commission 754510 Agencia Estatal de Investigación PID2019-111673GB-I00 Agencia Estatal de Investigación PID2019-111773RB-I00 Agencia Estatal de Investigación PGC2018-096955-B-C43 Agencia Estatal de Investigación PGC2018-101743-B-I00 Ministerio de Economía y Competitividad SEV-2017-0706 Ministerio de Economía y Competitividad RYC-2017-22330 Ministerio de Economía y Competitividad FPI-SO2019 Ministerio de Economía y Competitividad FPI-SO2018 Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-1506 |
Drets: | Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. |
Llengua: | Anglès |
Document: | Article ; recerca ; Versió publicada |
Matèria: | 2D materials ; Ab initio ; Heat transport ; Raman thermometry ; Transition metal dichalcogenides |
Publicat a: | Advanced materials, Vol. 34, issue 10 (March 2022) , art. 2108352, ISSN 1521-4095 |
9 p, 2.0 MB |