High Thermoelectric Performance SnTe with a Segregated and Percolated Structure

Abstract

A nanostructure has a significant role in enhancing the power factor and preventing the heat propagation for thermoelectric materials. Herein, we propose a unique segregated and percolated (SP) microphaseseparated structure to enhance the thermoelectric performance of SnTe. The SP structure is composed of insoluble SnTe and AgCuTe, in which AgCuTe with ultralow lattice thermal conductivity undergoes a solid-phase welding during a spark plasma sintering process and forms continuous percolated layers at the interface of isolated SnTe. The SP structure achieved a simultaneous scattering for low energy holes due to the energy offset of the valence band maximum between SnTe and AgCuTe and for phonons due to the noncoherent interfaces between SnTe and AgCuTe, resulting in a high Seebeck coefficient of ∼219.4 μV/K and a low lattice thermal conductivity of ∼1.1 W m −1 K −1 at 800 K for (SnTe) 0.55 (AgCuTe) 0.45 . The thermoelectric performance was further enhanced by means of the cosubstitution of In and Mn for Sn in the SnTe lattice, inducing resonance levels and extra phonon scattering. As a result, the SP structure combined with In/Mn codoping enable us to achieve a low lattice thermal conductivity of 0.47 W m −1 K −1 , a peak ZT of ∼1.45 at 800 K, and a high average ZT of ∼0.73 (400−800 K) for (Sn 0.98 In 0.01 Mn 0.01 Te) 0.75 (AgCuTe) 0.25 .

High Thermoelectric Performance in AgBiSe2-Incorporated n-Type Bi2Te2.69Se0.33Cl0.03

“…4,5 A desired outcome in the TE research is either higher S 2 σ or lower κ; however, navigating the counterinterrelationship (competing effects) of S, σ, and κ e to improve the ZT is very challenging due to their coupling through band structure and scattering mechanism. 6,7 Thus, various techniques such as band engineering, 8,9 nanostructuring, 10,11 tuning carrier concentration, etc. 12,13 have been developed over the years to decouple the three variables and enhance the thermoelectric performance of materials.…”

“…For decades, TE materials capable of converting waste heat into electrical energy and cooling solid-state applications have piqued global interest; − however, the efficacy of thermoelectric materials depends on how the counter-interrelation of the parameters that gave its mathematical expression is handled. The figure of merit is defined as ZT = S 2 σ T /κ = S 2 σ T /(κ e + κ lat ), where S , σ, κ, and T are the Seebeck coefficient, electrical conductivity, thermal conductivity (including electronic thermal conductivity κ e , lattice thermal conductivity κ lat ), and absolute temperature, respectively. , A desired outcome in the TE research is either higher S 2 σ or lower κ; however, navigating the counter-interrelationship (competing effects) of S , σ, and κ e to improve the ZT is very challenging due to their coupling through band structure and scattering mechanism. , Thus, various techniques such as band engineering, , nanostructuring, , tuning carrier concentration, etc. , have been developed over the years to decouple the three variables and enhance the thermoelectric performance of materials.…”

Thermally conductive polymer-based composites: fundamentals, progress and flame retardancy/anti-electromagnetic interference design

“…In recent years, a lot of research studies about electromagnetic waves by domestic and foreign scholars have mainly focused on electromagnetic shielding and absorption. 184,185…”

“…Composites with a uniform structure can be directly made by blending a conductor filler and an insulating resin and then processing and molding by opening mixing, internal mixing, injection molding and so on. Electrical conductors such as Fe, Cu, Au, and Ag are good anti-electromagnetic-interference and thermally conductive materials, and their thermal conductivity is determined by their electrons, phonons and electron-phonon coupling, [183][184][185] while their anti-electromagnetic-interference performance is determined by the reflection and absorption of electromagnetic waves caused by electron-electron interactions (i.e., Coulomb interactions) and electron-phonon interactions. 186,187 Therefore, these materials with high thermal and electrical conductivity show great application potential in anti-electromagnetic interference and thermal management fields.…”

Enhanced thermoelectric performance of In-doped and AgCuTe-alloyed SnTe through band engineering and endotaxial nanostructures

“…AgCuTe is a polycrystalline semiconductor in the quasi-binary phase diagram of Ag 2 Te-Cu 2 Te and always contains the Cu 2 Te second phase at room temperature. 29,30 Recently, Ma et al introduced AgCuTe nano-precipitates into the SnTe matrix to form a segregated and percolated structure, 31 which enhanced the scattering of phonons and electrons and thus improved the thermoelectric performance. However, the details, such as the effects of AgCuTe alloying on SnTe band structure and the types of introduced defects, need further study.…”