Design method of wearable two-dimensional asymmetric material with high thermoelectric conversion efficiency

Abstract

The invention discloses a design method of a wearable two-dimensional asymmetric material with high thermoelectric conversion efficiency. The method comprises the steps that (1) a two-dimensional chalcogenide MXY of an asymmetric Janus structure is designed, M = {Mo, W, Hf and Zr}, and X/Y = {S, Se and Te}; (2) calculating stable configurations of the 12 systems based on a density functional theory, and calculating electronic structure characteristics under the condition of considering spin-orbit coupling; (3) calculating the conductivity, the electron thermal conductivity and the Seebeck coefficient of the material by using the electron Boltzmann transport theory under the condition of considering the electron-phonon interaction; (4) meanwhile, the group velocity, scattering intensity and lattice thermal conductivity of phonons are obtained by using a phonon Boltzmann equation, and the thermoelectric figure of merit of the material is obtained; and (5) calculating the flexible mechanical properties of the system based on a density functional theory, wherein the flexible mechanical properties comprise fracture toughness and elastic modulus. The two-dimensional asymmetric material designed by the method has the advantages of high room-temperature thermoelectric conversion efficiency, high stability, excellent mechanical properties and the like.

Description

Technical field [0001] The invention belongs to the field of wearable thermoelectric materials, and relates to a design method of wearable two-dimensional asymmetric materials with high thermoelectric conversion efficiency. technical background [0002] Nowadays, the development of Internet of Things urgently needs its component units to obtain energy from the surrounding environment, so as to get rid of the space constraints brought by power supply facilities such as power lines and batteries. Thermoelectric materials use Seebeck effect to provide people with an ideal solution that can absorb energy from the thermal energy in the surrounding environment, and then convert it into the electrical energy required by devices. The parameter for evaluating thermoelectric conversion efficiency is called thermoelectric figure of merit, and its expression is ZT = S. 2 σ / (k e +k l ), s is Zeebek coefficient, σ is electrical conductivity, k is thermal conductivity, and t is absolute tempera...

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Problems solved by technology

[0005] Aiming at the problems of low thermoelectric conversion efficiency and poor mechanical stability of existing thermoelectric materials at room temperature, and it is difficult to improve the pa

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