Significantly reinforced thermoelectric performance in the novel 1T-Au6Se2 monolayer

Abstract

Ultra-low lattice thermal conductivity has long been a requirement for the high thermoelectric properties of materials. In this work, the novel 1T-Au6Se2 monolayer was obtained by introducing Au6 clusters into the selenide monolayer, and its electrical and thermal transport characteristics are investigated using first-principles computations supplemented with semi-classical Boltzmann transport theory. The calculation shows that the 1T-Au6Se2 monolayer exhibits ultra-low lattice thermal conductivity and excellent thermoelectric properties owing to its low phonon frequency, group velocity, and extremely strong anharmonicity. Based on strain engineering from 0% to 2%, the lattice thermal conductivity further reduces by restricting the thermal transport on the premise of maintaining outstanding electrical transport properties in the p-type doped system. Thence, the value of ZT for the p-type system increases nearly by 70% compared with the non-stressed state at 700 K. Our investigation indicates the ultra-low thermal conductivity and high ZT of the 1T-Au6Se2 monolayer that might be prepared in the lab, providing new insights into enhancing the thermoelectric performance of the material in the future.

First-Principles Thermoelectric Study of SrMgSi and CaMgGe Zintl-Phase Compounds

“…The electrical transport parameters were calculated using the Boltzmann transport theory, as implemented in the BoltzTrap code . The temperature-dependent relaxation time (τ) was calculated using the deformation potential theory, which relies on the coupling between electrons and acoustic phonons and can well describe the transport properties of various semiconductors. − (see the Supporting Information for calculation details) A dense k -mesh with 10,000 k points was sampled in the Brillouin zone, which results in well-converged electrical conductivity (Figure S5 of Supporting Information). Additionally, spin-–orbit coupling and relativistic effects were considered in our system for an accurate description of the band structures.…”

Novel room-temperature full-Heusler thermoelectric material Li2TlSb

“…[1][2][3][4][5] Thermoelectric (TE) materials, which can directly convert heat into electricity and vice versa, have attracted much attention. [6][7][8][9][10][11][12] The conversion efficiency of TE materials is measured by a figure of merit ZT = S 2 sT/(k L + k e ), where S, s, k e , k L , and T are Seebeck coefficient, electrical conductivity, electrical thermal conductivity, lattice thermal conductivity, and absolute temperature, respectively. 4,7 Therefore, an excellent thermoelectric material must have a high power factor PF (S 2 s) as well as a low thermal conductivity.…”

Ultralow Glassy Thermal Conductivity and Controllable, Promising Thermoelectric Properties in Crystalline o-CsCu5S3

“…A central focus in thermoelectric materials research is to notably enhance the conversion efficiency by minimizing irreversible heat transport and preserving favorable electrical transport properties. 3,4 Thus, the proposal of the phonon glass electron-crystal (PGEC) concept aims to identify highperformance thermoelectric materials. 5 In this paradigm, ordered crystals preserve favorable electronic properties while demonstrating lattice thermal conductivity (κ L ) comparable to that of amorphous solids or glasses.…”

“…Thermoelectric materials, directly converting heat into electricity, are presently being explored for various feasible waste heat recovery systems, including space-based applications and thermal data storage devices. , Generally, the thermoelectric maximum efficiency of thermoelectric materials is characterized by the dimensionless figure of merit, ZT = S 2 σ/κ, where S , σ, and κ represent the Seebeck coefficient, electrical conductivity, and thermal conductivity, respectively. A central focus in thermoelectric materials research is to notably enhance the conversion efficiency by minimizing irreversible heat transport and preserving favorable electrical transport properties. , Thus, the proposal of the phonon glass electron-crystal (PGEC) concept aims to identify high-performance thermoelectric materials . In this paradigm, ordered crystals preserve favorable electronic properties while demonstrating lattice thermal conductivity (κ L ) comparable to that of amorphous solids or glasses.…”