CuSbSe-Alloying-Induced High Thermoelectric Performance and Mechanical Robustness in BiTe-Based Thermoelectric Materials.

BiTe-based thermoelectric materials remain the only commercially viable candidates for low-grade waste heat recovery. However, their moderate thermoelectric performance and limited mechanical robustness constrain broader industrial applications. Here, a synergistic enhancement of both the thermoelectric and mechanical properties of BiSbTe is demonstrated by alloying with CuSbSe via high‑energy ball milling followed by hot pressing.

Enhanced Band-Crystal Engineering Drives Superior Power Generation in GeTe.

Optimizing both electrical and thermal performance in thermoelectric (TE) materials is challenging due to the inherent coupling between carrier and phonon transport. To address this, targeted modulation of band structure and crystal lattice is achieved in the optimized GeZrPbTe(CuTe) sample. Zr/Pb incorporation optimizes the band structure and significantly enhances the Seebeck coefficient, while Pb-substituted Ge sites occupy a more symmetric geometric center, reducing Ge vacancies, increasing crystal symmetry, and facilitating delocalized carrier transport.

Enhancing n-Type PbTe Thermoelectrics via Valley Shape Modulation and Core-Shell Precipitates.

Achieving both a high power factor and low lattice thermal conductivity in thermoelectric (TE) materials has been a longstanding challenge. Herein, we report significant advancements in PbTe-based materials through a band-sharpening approach that incorporates valley modification alongside an innovative core-shell structural strategy. The n-type AgPbSnTe-0%AgTe compounds demonstrate substantial band sharpening, resulting in exceptional electronic performance due to enhanced carrier mobility, despite a low density of states effective mass and moderate Seebeck coefficients.

Optimized Interface Engineering Enhances Carrier and Phonon Scattering for Superior Thermoelectric Performance in Yb-Filled Skutterudites.

Thermoelectric (TE) performance in materials is often constrained by the strong coupling between carrier and phonon transport, necessitating trade-offs between electrical and thermal properties that limit improvements in the figure of merit (). Herein, a novel strategy is proposed to achieve simultaneous energy filtering and enhanced phonon scattering, effectively optimizing the TE properties of CoSb-based skutterudites. By introducing CuTe nanoprecipitates into the YbCoSb matrix, interfacial barriers are formed, which selectively filter low-energy charge carriers, significantly improving the Seebeck coefficient while maintaining high carrier mobility.

Lattice defect engineering advances n-type PbSe thermoelectrics.

Te-free thermoelectrics have garnered significant interest due to their immense thermoelectric potential and low cost. However, most Te-free thermoelectrics have relatively low performance because of the strong electrical and thermal transport conflicts and unsatisfactory compatibility of interfaces between device materials. Here, we develop lattice defect engineering through Cu doping to realize a record-high figure of merit of ~1.

Enhanced Thermoelectric Properties in Na-Doped PbTe via Pb Vacancies and Trace Eu Doping.

Enhancing the thermoelectric performance of Na-doped PbTe is challenging due to the low solubility of Na, a problem that remains insufficiently explored from a theoretical perspective, particularly regarding the role of Pb vacancies. In this study, we utilize crystal orbital Hamilton population and electron localization function analyses to investigate the impact of Pb vacancies on Na solubility in PbTe. Our findings indicate that Pb vacancies strengthen Na-Te bonding and improve electron localization around Te atoms, which reduces the formation of Te vacancies and facilitates a higher dissolution of Na.

Pseudo-Nanostructuring and Grain Refinement Enhance the Near-Room-Temperature Thermoelectric Performance in n-type PbSe.

PbSe, a promising Te-free thermoelectric material for medium-temperature applications, has garnered considerable attention due to its substantial thermoelectric potential and relatively low cost. However, the vast majority of research on polycrystalline PbSe thermoelectrics has focused primarily on improving its medium-temperature performance, often neglecting the enhancement of near-room-temperature performance and effective module design. Here, an n-type polycrystalline PbSe material (CuPbGeSe) is presented that exhibits a room-temperature zT of ≈0.

Hydrothermal Synthesis of Cancrinite from Coal Gangue for the Immobilization of Sr.

The primary objective of this study is to investigate and develop a rapid and effective method for the immobilization of Sr in the event of a nuclear leakage incident. Coal gangue, an underutilized form of solid waste from the coal industry, can be used as a raw material for curing Sr due to its high content of silica-alumina oxides. In the present study, Sr was successfully solidified in cancrinite synthesized using a hydrothermal method with coal gangue as raw material.

Promoted Na Solubility and Modified Band Structure for Achieving Exceptional Average by Extra Mn Doping in PbTe.

Na doping strategy provides an effective avenue to upgrade the thermoelectric performance of PbTe-based materials by optimizing electrical properties. However, the limited solubility of Na inherently restricts the efficiency of doping, resulting in a relatively low average , which poses challenges for the development and application of subsequent devices. Herein, to address this issue, the introduced spontaneous Pb vacancies and additional Mn doping synergistically promote Na solubility with a further modified valence band structure.

Multifunctional GeMnTe Synergistically Optimizes Thermoelectric Properties of SnTe-InTe Alloys.

SnTe-InTe alloys ensure excellent electrical properties in the whole temperature region due to the resonant level. Nevertheless, temperature-sensitive resonance states and single phonon scattering restrict further improvement of thermoelectric performance. Consequently, it is anticipated that additional electrically independent scattering sources should be introduced to impede phonon transport.

Band engineering enhances thermoelectric performance of Ag-doped SnSe.

Ag doping can effectively increase the carrier concentration of-type SnSe polycrystalline, thereby enhancing the thermoelectric (TE) performance. However, the key role of the transport valence band in Ag-doped SnSe remains unclear. Particularly, understanding the influence of evaluating the optimal balance between band convergence and carrier mobility on weighted mobility is a primary consideration in designing high-performance TE materials.

Lead Vacancy Promotes Sodium Solubility to Achieve Ultra-High zT in Only Ternary Pb Na Te.

Chemical doping of sodium is an indispensable means to optimize thermoelectric properties of PbTe materials, while a bottleneck is that an aliovalent atom doping leads to spontaneous intrinsic defects in the PbTe matrix, resulting in low dopant solubility. Therefore, it is urgent to improve the doping efficiency of Na for maximizing optimization. Here, an amazing new insight that the intentionally introduced Pb vacancies can promote Na solubility in ternary Pb Na Te is reported.

Structure Optimization and Multi-frequency Phonon Scattering Boosting Thermoelectrics in Self-Doped CoSb-Based Skutterudites.

The utilization of thermoelectric devices that directly convert waste heat to electricity is an effective approach to alleviate the global energy crisis. However, the low efficiency of thermoelectric materials has puzzled the widespread applications. The CoSb-based skutterudites are favored by device integration due to the excellent thermal stability, while the development of pristine CoSb materials is limited by the ultra-high thermal conductivity and the poor Seebeck coefficient.

Comprehensive Insight into -Type BiTe-Based Thermoelectrics near Room Temperature.

BiTe is a well-recognized material for its unique properties in diverse thermoelectric applications near room temperature. The considerable efforts on BiTe-based alloys have been extremely extensive in recent years, and thus the latest breakthroughs in high-performance -type (Bi, Sb)Te alloys are comprehensively reviewed to further implement applications. Effective strategies to further improve the thermoelectric performance are summarized from the perspective of enhancing the power factor and minimizing the lattice thermal conductivity.

CuTe Incorporation-Induced High Average Thermoelectric Performance in -Type BiTe Alloys.

-Type (Bi, Sb)Te alloys are attractive materials for near-room-temperature thermoelectric applications due to their high atomic masses and large spin-orbit interactions. However, their narrow band gaps originating from spin-orbit interactions lead to bipolar excitation, thereby limiting average thermoelectrics within a local temperature region (300-400 K). Here, we introduce CuTe into the BiSbTe (BST) lattice to implement high thermoelectrics over a wide temperature range.

Isotropic Thermoelectric Performance of Layer-Structured n-Type BiTeSe by Cu Doping.

The lamellar structure of (Bi,Sb)(Te,Se) alloys makes it difficult to achieve isotropic thermoelectric properties in the directions along and perpendicular to the -axis, especially for n-type samples. In this work, by introducing Cu in polycrystalline n-type CuBiTeSe and applying the traditional synthesis process of high-energy ball milling and hot pressing, substantial enhancement of the thermoelectric figure of merit is obtained in both in-plane and out-of-plane directions. The intercalated Cu not only provides electron transport media for mobility improvement but also reduces the lattice thermal conductivity owing to the strain fluctuation.

Enhancing Thermoelectrics for Small-Bandwidth n-Type PbTe-MnTe Alloys via Balancing Compromise.

Small-bandwidth n-type PbTe-MnTe alloys effectively modify the valley shape, while it also inevitably aggravates the deterioration of carrier mobility as nonpolar phonons dominate the scattering. It is found that a trace amount of Cu doping can alleviate the compromises among thermoelectric parameters, thereby significantly optimizing the electrical-transport performance near room temperature of n-type PbTe-MnTe alloys. The single-Kane model reveals that the physical origin of performance improvement lies in the carrier mobility enhancement and self-optimization of carrier concentration.

Enhancing Near-Room-Temperature GeTe Thermoelectrics through In/Pb Co-doping.

The traditional thermoelectric material GeTe has drawn much attention recently because of the reported high thermoelectric performance of the rhombohedral phase in low-temperature ranges, where the split and Σ band can be reconverged to have a small energy offset and thus high density of state effective mass according to the rhombohedral angle. In addition, In doping in GeTe is also reported to enhance the density of effective mass and therefore increase the Seebeck coefficient because of the induced resonant levels. In this work, In and Pb are doped in GeTe, and In doping leads to an increase in the rhombohedral angle and thus enhanced density of state effective mass in addition to the resonant effect.

Structural Evolution of High-Performance Mn-Alloyed Thermoelectric Materials: A Case Study of SnTe.

Mn alloying in thermoelectrics is a long-standing strategy for enhancing their figure-of-merit through optimizing electronic transport properties by band convergence, valley perturbation, or spin-orbital coupling. By contrast, mechanisms by which Mn contributes to suppressing thermal transports, namely thermal conductivity, is still ambiguous. A few precedent studies indicate that Mn introduces a series of hierarchical defects from the nano- to meso-scale, leading to effective phonon scattering scoping a wide frequency spectrum.

High Quality Factor Enabled by Multiscale Phonon Scattering for Enhancing Thermoelectrics in Low-Solubility n-Type PbTe-CuTe Alloys.

The fundamental challenge for enhancing the thermoelectric performance of n-type PbTe to match p-type counterparts is to eliminate the Pb vacancy and reduce the lattice thermal conductivity. The Cu atom has shown the ability to fill the cationic vacancy, triggering improved mobility. However, the relatively higher solubility of CuTe limits the interface density in the n-type PbTe matrix, leading to a higher lattice thermal conductivity.

Optimized Strategies for Advancing n-Type PbTe Thermoelectrics: A Review.

p-Type and n-type thermoelectric semiconductor materials with compatible performance are key components for thermoelectric devices. Great improvement in thermoelectric performance has been achieved in p-type PbTe, whereas the n-type counterpart still shows much inferior thermoelectric performance compared to that of the p-type PbTe. This inspires many strategies focused on advancing n-type PbTe thermoelectrics.

Superconductivity related to the suppression of exciton formation in 1T-TiSe.

In strongly correlated electron system, the impact of elementary substitution or intercalation plays a crucial role in determining electronic ground state among various macroscopic quantum phases such as charge order and superconductivity. Here, we report that simultaneous Cu intercalation and Ta substitution at Ti site in 1T-CuTiTaSeinduce an intrinsic electronic phase diagram, characterized by an inherent superconducting transition in theregion of 0 ⩽⩽ 0.12, with a maximum superconducting transition temperatureof 2.

Reducing Effective Mass for Advancing Thermoelectrics in Sb/Bi-Doped AgCrSe Compounds.

Liquid-like materials have attracted increasing attention, owing to their phonon-liquid electron-crystal feature. As a typical representative, the superionic conductor AgCrSe is regarded as a promising thermoelectric for its intrinsic ultralow lattice thermal conductivity. The primary challenge for achieving high thermoelectric performance is to enhance the inferior electronic performance in AgCrSe compounds.

Texturization-Induced In-Plane High-Performance Thermoelectrics and Inapplicability of the Debye Model to Out-of-Plane Lattice Thermal Conductivity in Misfit-Layered Chalcogenides.

Texturization tuning is of crucial significance for designing and developing high-performance thermoelectric materials and devices. Here, we report for the first time that a strong texturization effect induces an in-plane high-performance thermoelectric and an out-of-plane low lattice thermal conductivity in Sb-substituted misfit-layered (SnS)(TiS) alloys. In the in-plane direction, the oriented texture promotes a high carrier mobility, contributing to the maximization of the power factor (∼0.