By the coordinated implementation of shallow impurity level and multiscale defect engineering, this study achieves the simultaneous optimization of electrical transport and thermal conduction in GeTe-based thermoelectric (TE) materials. This synergistic mechanism originates from the unique electronic configuration of Ni, whose d–sp orbital hybridization introduces shallow impurity levels that promote valence band convergence, thereby enhancing the effective mass of carriers and the Seebeck coefficient. Concurrently, in situ reactions between Ni and Ge form NiGe nanophases (10–30 nm), constructing multiscale defect structures that enable full-spectrum phonon scattering and suppress the lattice thermal conductivity of the Ge_0.885Sb_0.1Ni_0.015Te sample to ~0.8 W∙m⁻¹∙K⁻¹ at 323 K. Leveraging this cooperative optimization, Ge_0.885Sb_0.1Ni_0.015Te attains a peak dimensionless figure of merit (ZT) value of 2.15 at 773 K and an average ZT_avg of ~1.45 (323–773 K). A fabricated single-leg device achieves a conversion efficiency of ~10% under ∆T = 420 K, ranking among the top performances in the field. This work establishes a solid foundation for enhancing the performance and expanding the applications of GeTe-based TE materials.

Flexible thermoelectric generators (f-TEGs) have emerged as among the most promising candidates to address the persistent energy supply challenges associated with wearable electronics. To achieve practical applications of inorganic π-shaped f-TEGs rapidly requires enhancing their output power density, which represents the primary and pivotal objective. This review distills three main factors that govern output power density, namely, the power factor of thermoelectric materials, the geometric and packaging configurations of f-TEGs, as well as the effective temperature gradient across the f-TEGs. Further, the principal optimization strategies adopted for these factors over recent years are outlined. The strategies encompass approaches such as carrier concentration modulation, carrier scattering mechanism regulation, and energy band engineering to enhance the power factor, finite element simulations and numerical computations for optimizing geometric structure and packaging, and the integration of hydrogels and phase change materials into flexible heat sinks to establish and maintain sufficiently large temperature differences. Additionally, the discussion extends to the flexibility of inorganic materials and generators themselves. Finally, the concluding section addresses the challenges and critical issues confronting the development of flexible thermoelectric materials and generators.

Diffusion barrier materials (DBMs) are critical for the stability and efficiency of thermoelectric devices. Conventional DBM selection via density functional theory (DFT) calculations is computationally intensive. Here, we introduce an efficient screening approach that employs substitution energy as a surrogate for interfacial reaction energy, significantly reducing computational demand. By integrating substitution energy with migration energy barriers, we identify Ni as a robust DBM for Ag₂Se. Experimental validation confirms that Ni/Ag₂Se joints exhibit low contact resistivity (6.6 μΩ·cm²) and high thermal stability after 30 days of thermal aging. The Te-free Ag₂Se/MgAgSb devices achieve a maximum cooling temperature difference of 68 K at 350 K, comparable to state-of-the-art Ag₂Se/Bi₂Te₃ devices, while demonstrating excellent durability over 2000 power cycles. This strategy offers a rapid and reliable framework for DBM selection, accelerating the advancement of high-performance thermoelectric devices.

GeTe is a promising medium-temperature thermoelectric material. However, an excessively high concentration of Ge holes leads to a high hole carrier concentration, which can degrade its performance. Though carrier concentration reduction via doping has been pursued as a principal optimization approach, the strong interdependence between key transport parameters and carrier concentration severely limited the overall enhancement efficacy. In this work, a simple composite method is employed to achieve synergistic optimization of carrier concentration and carrier mobility, thereby increasing the power factor and reducing the lattice thermal conductivity. Sb and Fe form a core-shell structure, which effectively scatters phonons and reduces the lattice thermal conductivity, achieving a minimum value of 0.59 W·m⁻¹·K⁻¹ at 723 K. Additionally, Fe doping enhances the effective mass, improves the Seebeck coefficient, and significantly boosts the power factor, which reaches a peak value of 43.0 μW·cm⁻¹·K⁻² at 623 K. The results demonstrate that the sample Ge_0.885Sb_0.1Fe_0.015Te achieves a maximum zT of approximately 2.13 at 723 K and an average zT (zT_avg) of 1.43 within the temperature range of 323 K–773 K. This work provides an effective path to enhance the performance of GeTe-based thermoelectric materials.

Two-dimensional (2D) materials such as metal chalcogenides have great potential as cathode catalyst materials for lithium oxygen batteries (LOBs) due to their large specific surface area and stable chemical properties. However, thus far, due to the lack of theoretical prediction methods, huge load on catalytic synthesis and performance evaluation is concerned. Herein, we reported a theoretical method for 2D metal chalcogenides as catalysts for LOBs using first principles density functional theory (DFT) calculations. We extracted key parameters that affect the overpotential, including Li–X bond energy (X represents chalcogen elements) and catalyst lattice constant, and theoretically predicted the catalytic performance. The DFT calculation results indicate that MoS₂ with appropriate Li–X bond energy and lattice constant has the lowest theoretical overpotential, and its cyclic stability should be higher than other materials under the same conditions. Significantly, we experimentally validated the theoretical predictions presented above. The experimental results shows that pure MoS₂ with 2H phase can stably work for more than 220 cycles at a current density of 500 mA/g, and the actual overpotential is lower than other metal chalcogenides. This work provides a swift pathway to accelerate searching high performance catalytic in LOBs.

Silicon-germanium (SiGe) alloy, as a representative medium and high temperature thermoelectric material, has been widely applied in auxiliary power supply of space exploration spacecraft. SiGe alloy has significant advantages such as stable structure, rich elements, non-toxic, high-temperature resistance, and easy industrial integration. However, the lower thermoelectric performance limits the practical application and promotion of SiGe alloys. Based on above, this article comprehensively describes the collaborative optimization strategies of SiGe alloys in both electrical and thermal properties, as well as relevant latest research progress. In terms of electrical properties, the importance of modulation doping and energy filtering mechanism to improve the power factor of SiGe alloys was revealed; In terms of thermal properties, a detailed review was conducted on the strategies for reducing lattice thermal conductivity of SiGe alloys, including nanostructure, SiGe-metal silicide/silicide composite, and SiGe-oxide composite strategies. And the effects of different optimization strategies on reducing lattice thermal conductivity were compared. Through collaborative optimization of electrical and thermal transport parameters, the zT values of p-type and n-type SiGe-based thermoelectric materials reached 1.81 (1100 K) and 1.7 (1173 K), respectively, which are the highest values reported in current research. This article provides a certain reference for further optimization of the thermoelectric properties of SiGe bulk materials.

The highly efficient degradation and purification of organic pollutants in wastewater by photocatalysis is still challenging. In this study, a piezoelectric potential-activated interfacial electric field (IEF) was constructed to endow BiFeO₃@BaTiO₃ (BFO@BTO) heterojunction with the ability to serve as a round-the-clock photocatalyst for polluted water remediation. BFO@BTO heterojunction is composed of BiFeO₃ nanoparticles decorated on the surface of BaTiO₃ nanorods, which shortens the carrier migration path. More importantly, the IEF can be activated and reconstructed under ultrasonic wave irradiation, leading to a lower potential barrier and enhanced separation efficiency for photogenerated carriers. The degradation rate constant k value of BFO@BTO heterojunction reached 0.038 min⁻¹, which was 1.9 and 7.0 times greater than that of piezocatalysis and photocatalysis alone, respectively. It also exhibited excellent stability in three light‒dark cycles for high concentrations (25 mg·L⁻¹) of rhodamine B (RhB) and tetracycline hydrochloride (TC). This study provides a promising strategy for designing highly active photoassisted piezocatalysts for environmental energy utilization and round-the-clock catalysis.

SiGe based alloy is a promising medium-high temperature thermoelectric material that has been applied in the field of aerospace exploration. So far, utilizing the second phase to promote the scattering of phonons is a common way to improve the thermoelectric performance of SiGe based alloy, but this often deteriorates the electrical properties. In this study, the Si₈₀Ge₂₀P₁/CoSi₂ composites have been prepared by mechanical alloying and spark plasma sintering, and the content of cobalt silicide (CoSi₂) nanoparticles have been manipulated. Since the CoSi₂ nanoparticles possess higher carrier concentration and smaller work function than the Si₈₀Ge₂₀P₁ matrix, the carrier concentrations of composites have been pushed up due the charge transfer effect. Meanwhile, the formation of nano-sized phase interfaces and stacking faults in the composites has enhanced the scattering of low-frequency phonons. As a result, the optimal power factor of 3.41 mW·m⁻¹·K⁻² and thermal conductivity of 2.29 W·m⁻¹·K⁻¹ have been achieved, and the corresponding zT reaches up to 1.3 in the Si₈₀Ge₂₀P₁+0.5% CoSi₂ (in mole) composite at 873 K. This work provides a new idea for developing the performance of SiGe based alloy.

SiGe is recognised as an excellent thermoelectric material with superior mechanical properties and thermal stability in regions with high temperatures. This study explores a novel strategy for co-regulating thermoelectric transport parameters to achieve high thermoelectric properties of p-type SiGe in the mid-temperature region by incorporating nano-TaC into SiGe combined ball milling with spark plasma sintering. By optimizing the amount of TaC in the SiGe matrix, the power factors were significantly increased due to the modulation doping effect based on the work function matching of SiGe with TaC. Simultaneously, the ensemble effect of the nanostructure leads to a significant decrease in thermal conductivity. Thus, a high ZT of 1.06 was accomplished at 873 K, which is 64 % higher than that of typical radioisotope thermoelectric generator. Our research offers a novel strategy for expanding and enhancing the thermoelectric properties of SiGe materials in the medium temperature range.