Search Results (995)

The Cu-Cr-Zr alloy is regarded as an optimal material for high-end electronic information industries owing to its high electrical strength, high conductivity, and outstanding softening resistance. Nevertheless, the impacts of Cr content and microstructure evolution on performance enhancement during the processing stage remain unclear. In this research, Cu-xCr-0.1Zr alloys with varying Cr contents were fabricated via the thermo-mechanical approach. The microstructure evolution, as well as the mechanical and electrical properties before and after aging were investigated. It was discovered that Cr can mitigate the grain deformation degree of the copper alloy during cold rolling, notably augment the proportion of large-angle grain boundaries, and diminish the dislocation density induced by plastic deformation. As the Cr content increases, the conductivity of the sample declines from 86% IACS (0Cr) to 34.1% IACS (1.8Cr), and the tensile strength rises from 435 MPa (0Cr) to 542 MPa (1.8Cr) after cold rolling; the conductivity decreases from 89.4% IACS (0Cr) to 77.3% IACS (1.8Cr), and the tensile strength increases from 278 MPa to 607 MPa (1.0Cr). Based on the comprehensive outcomes, the aged 1.0Cr sample, with a tensile strength of 607 MPa and a conductivity of 80.9% IACS, satisfies the performance requirements of high-strength and high-conductivity copper alloys. Full article

Mechanical and thermoelectric performance of a SiGe thermoelectric module were investigated through finite element analysis. N-type and P-type SiGe thermoelectric materials were synthesized, and their mechanical and thermoelectric properties were experimentally measured. Thermal stress distributions within the SiGe module and the integrated “heat collector–module–heat sink” assembly are simulated, and the results were compared with the measured mechanical strength of the SiGe materials. The simulations show that among the three electrode structures evaluated—C/W/C sandwich, 0.5 mm W/C, and 0.1 mm W/C—the C/W/C sandwich configuration yields the lowest thermal stress. An inter-leg spacing of 0.5 mm also leads to reduced stress compared to a 0.1 mm gap. However, fully constraining the cold end or directly integrating the module with heat collection and dissipation components significantly increases thermal stress. The use of copper cooling plates induces higher stress than C-C plates, exceeding the tolerable strength of the materials. Simulation of a module with 28 SiGe legs (each 10 mm × 10 mm × 1.5 mm) predicts an output power of 7.42 W and a conversion efficiency of 7.11% at a hot-side temperature of 967 °C and a cold-side temperature of 412 °C. Full article

Tin selenide (SnSe) is a sustainable, lead-free IV–VI semiconductor whose layered orthorhombic crystal structure induces pronounced electronic and phononic anisotropy, enabling diverse energy-related functionalities. This review systematically summarizes recent progress in understanding the structure–property–processing relationships that govern SnSe performance in thermoelectric and optoelectronic applications. Key crystallographic characteristics are first discussed, including the temperature-driven Pnma–Cmcm phase transition, anisotropic band and valley structures, and phonon transport mechanisms that lead to intrinsically low lattice thermal conductivity below 0.5 W m⁻¹ K⁻¹ and tunable carrier transport. Subsequently, major synthesis strategies are critically compared, spanning Bridgman and vertical-gradient single-crystal growth, spark plasma sintering and hot pressing of polycrystals, as well as vapor- and solution-based thin-film fabrication, with emphasis on process windows, stoichiometry control, defect chemistry, and microstructure engineering. For thermoelectric applications, directional and temperature-dependent transport behaviors are analyzed, highlighting record thermoelectric performance in single-crystal SnSe at hi. We analyze directional and temperature-dependent transport, highlighting record thermoelectric figure of merit values exceeding 2.6 along the b-axis in single-crystal SnSe at ~900 K, as well as recent progress in polycrystalline and thin-film systems through alkali/coinage-metal doping (Ag, Na, Cu), isovalent and heterovalent substitution (Zn, S), and hierarchical microstructural design. For optoelectronic applications, optical properties, carrier dynamics, and photoresponse characteristics are summarized, underscoring high absorption coefficients exceeding 10⁴ cm⁻¹ and bandgap tunability across the visible to near-infrared range, together with interface engineering strategies for thin-film photovoltaics and broadband photodetectors. Emerging applications beyond energy conversion, including phase-change memory and electrochemical energy storage, are also reviewed. Finally, key challenges related to selenium volatility, performance reproducibility, long-term stability, and scalable manufacturing are identified. Overall, this review provides a process-oriented and application-driven framework to guide the rational design, synthesis optimization, and device integration of SnSe-based materials. Full article

A deterministic platform for engineering epitaxial strain in CaMnO_3-δ (CMO) thermoelectric thin films is demonstrated using pulsed laser deposition, enabling precise control of the interplay between strain state and oxygen vacancy formation. High-quality epitaxial CMO films are grown on four different single crystalline substrates, which impose fully relaxed, partially relaxed, low tensile, and high tensile strain states, respectively. Increasing tensile strain induces a monotonic expansion of the unit cell volume and a systematic rise in oxygen vacancy concentration. Oxygen vacancies increase carrier concentration but decrease mobility due to enhanced scattering. Reducing tensile strain suppresses scattering of electrons by oxygen vacancies and increases both electrical conductivity (σ) and the Seebeck coefficient (S), mitigating the conventional inverse relationship between S and σ. Fully relaxed films exhibit σ approximately four orders of magnitude higher at room temperature than highly tensile strained films. These relaxed films also show the highest power factor (PF = S²·σ), exceeding strained films by up to six orders of magnitude. Strain-controlled oxygen vacancies thus provide a direct route to optimize charge transport and maximize the thermoelectric performance of CMO thin films. Full article

To improve the comprehensive performance of indium oxide (In₂O₃) thermoelectric materials, this study systematically investigates the regulatory effects of tantalum (Ta) doping on their electrical transport characteristics, thermoelectric conversion efficiency, and mechanical properties. The results show that Ta doping achieves synchronous optimization of multiple properties through precise regulation of crystal structure, electronic structure, and microdefects. In terms of electrical transport, the electron doping effect of Ta⁵⁺ substituting In³⁺ and the introduction of impurity levels lead to a continuous increase in carrier concentration; lattice relaxation and impurity band formation at high doping concentrations promote mobility to first decrease and then increase, resulting in a significant growth in electrical conductivity. Although the absolute value of the Seebeck coefficient slightly decreases, the growth rate of electrical conductivity far exceeds the attenuation rate of its square, increasing the power factor from 1.83 to 5.26 μWcm⁻¹K⁻² (973 K). The enhancement of density of states near the Fermi level not only optimizes carrier transport efficiency but also provides electronic structure support for synergistic performance improvement. For thermoelectric conversion efficiency, the substantial increase in power factor collaborates with thermal conductivity suppression induced by lattice distortion and impurity scattering, leading to a leapfrog increase in ZT value from 0.055 to 0.329 (973 K). In terms of mechanical properties, lattice distortion strengthening, formation of strong Ta-O covalent bonds, and dispersion strengthening effect significantly improve the Vickers hardness of the material. Ta doping breaks the bottleneck of mutual property constraints in traditional modification through an integrated mechanism of “electronic structure regulation-carrier transport optimization-multiple performance synergistic enhancement”, providing a key strategy for designing high-performance indium oxide-based thermoelectric materials and facilitating their practical application in the field of green energy conversion. Full article

Carbon nanocomposites have gained interest due to the rapid development of nanotechnology. The graphite-based composites have been demonstrated to possess unique mechanical, electrical, and thermal properties. This paper presents a facile one-step sonochemical synthesis of antimony sulfoiodide (SbSI)/graphite nanocomposite. The weight concentrations of graphite in the prepared material varied from 0% to 33.3%. The morphology and chemical composition of the SbSI/graphite nanocomposites are studied with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), respectively. SEM examination shows that SbSI/graphite nanocomposite consists of one-dimensional SbSI nanostructures and graphite microparticles. The influence of graphite concentration on the energy band gap of SbSI/graphite nanocomposite is investigated using diffuse reflectance spectroscopy (DRS). The prepared materials are cold-pressed to obtain the bulk samples. They are characterized by direct current (DC) electrical measurements and thermoelectric examination. The increase in the graphite concentration in the SbSI/graphite nanocomposite resulted in a significant reduction in the electrical resistivity of the material. The Seebeck coefficients of the pristine SbSI nanowires and SbSI/graphite nanocomposite are determined for the first time. The investigations of the thermoelectric effect reveal that these nanomaterials exhibited p-type electrical conductivity. The thermoelectric power factor of the SbSI/graphite nanocomposite is examined as a function of the graphite concentration. The presented work demonstrates the comprehensive optical, electrical, and thermoelectric characterization of novel hybrid SbSI/graphite nanocomposites, which has not been studied before. Full article

To address the low energy conversion efficiency and weak mechanical strength of In₂O₃ thermoelectric materials for Aiye Processing Equipment, this study systematically investigated the regulatory effects and mechanisms of Ce doping on In₂O₃’s thermoelectric and mechanical properties via experiments. In₂O₃ samples with varying Ce contents were prepared, and property-microstructure correlations were analyzed through electrical/thermal transport tests, Vickers hardness measurements, and crystal structure characterization. Results show Ce doping synergistically optimizes In₂O₃ properties through multiple mechanisms. For thermoelectric performance, Ce⁴⁺ regulates carrier concentration and mobility, enhancing electrical conductivity and power factor. Meanwhile, lattice distortion from Ce-In atomic size differences strengthens phonon scattering, reducing lattice and total thermal conductivity. These effects boost the maximum ZT from 0.055 (pure In₂O₃) to 0.328 at 973 K obtained by x = 0.0065, improving energy conversion efficiency significantly. For mechanical properties, Ce doping enhances Vickers hardness and plastic deformation resistance via solid solution strengthening (lattice distortion hinders dislocations), microstructure densification (reducing vacancies/pores), Ce-O bond strengthening, and defect pinning. This study confirms Ce doping as an effective strategy for simultaneous optimization of In₂O₃’s thermoelectric and mechanical properties, providing experimental/theoretical support for oxide thermoelectric material development and valuable references for their medium-low temperature energy recovery applications. Full article

The exploration of chalcogenides is on the rise owing to their desirable optical, electronic, thermoelectric, and thermal properties. Chalcogenide materials have been investigated for possible applications in areas such as non-linear optics and solar cells. Among these materials are BaTiS₃ and BaTiSe₃. BaTiS₃ has shown promise in the above-mentioned applications due to its low thermal conductivity. However, neither the thermal properties of BaTiSe₃ nor the mechanical properties of both BaTiS₃ and BaTiSe₃ have been reported. In this work, we performed a computational study of the mechanical and thermal properties of both materials within the density functional theory using Quantum Espresso and BoltzTrap2 codes, employing generalized gradient approximation. The results showed that the computed thermal conductivity of BaTiS₃ at 0.43 W/m/K is comparable to the literature values. The computed elastic constants of BaTiS₃ (bulk modulus of 44.7 GPa, shear modulus of 11.2 GPa, Young’s modulus of 29.6 GPa, and Vickers hardness of 1.053 GPa) were higher than those of BaTiSe₃. The calculated properties obtained in this work add to the literature on the properties of BaTiS₃ and BaTiSe₃. However, since the work was computational, the results can be verified by an experimental investigation. Full article

Magnetic soft manganese–zinc ferrite in a concentration scale ranging from 100 to 500 phr was incorporated into acrylonitrile-butadiene rubber. The work was focused on the investigation of manganese–zinc ferrite content on electromagnetic interference shielding effectiveness and mechanical properties of composites. The rubber-based products used in industrial practice should not only provide good utility and functional properties but should also exhibit good stability towards degradation factors, like oxygen and ozone. Therefore, the samples were exposed to the thermo-oxidative and ozone ageing conditions, and the influence of both factors on the composites’ properties was evaluated. The results demonstrated that the incorporation of ferrite into the rubber matrix resulted in the fabrication of composites with absorption-shielding performance. It was demonstrated that the higher the ferrite content, the lower the absorption-shielding ability. Electrical and thermal conductivity showed an increasing trend with increasing content of ferrite. On the other hand, the study of mechanical properties implied that ferrite acts as a non-reinforcing filler, leading to a decrease in tensile characteristics. Thermo-oxidative ageing tests revealed that ferrite, mainly in high amounts, could accelerate the degradation processes in composites. Though the absorption-shielding performance of composites after ageing corresponded to that of their equivalents before ageing, it can also be concluded that the higher the amount of ferrite in the rubber matrix, the lower the composites’ stability against ozone ageing. Full article

The development of human-robot interfaces that support daily social interaction requires biomimetic innovation inspired by the sensory receptors of the five human senses (tactile, olfactory, gustatory, auditory, and visual) and employing soft materials to enable natural multimodal sensing. The receptors have a structure formulated by variegated shapes; therefore, the morphological mimicry of the structure is critical. We proposed a spring-like structure which morphologically mimics the roll-type structure of the Meissner corpuscle, whose haptic performance in various dynamic motions has been demonstrated in another study. This study demonstrated the gustatory performance by using the roll-type Meissner corpuscle. The gustatory iontronic mechanism was analyzed using electrochemical impedance spectroscopy with an inductance-capacitance-resistance meter to determine the equivalent electric circuit and current-voltage characteristics with a potentiostat, in relation to the hydrogen concentration (pH) and the oxidation-reduction potential. In addition, thermo-sensitivity and tactile responses to shearing and contact were evaluated, since gustation on the tongue operates under thermal and concave-convex body conditions. Based on the established properties, the roll-type Meissner corpuscle sensor enables the iontronic behavior to provide versatile multimodal sensitivity among the five senses. The different condition of the application of the electric field in the production of two-types of A and B Meissner corpuscle sensors induces distinctive features, which include tactility for the dynamic motions (for type A) or gustation (for type B). Full article

The development of miniaturized, integrated, and flexible thermoelectric devices has intensified the demand for high-performance thermoelectric semiconductors. While significant advances have been made in optimizing their thermoelectric properties, mechanical performance in terms of the strength and ductility has remained a challenge. Consequently, the inherent brittleness and insufficient mechanical robustness of inorganic thermoelectric semiconductors present a major barrier to their commercial applications. Therefore, it is essential to develop thermoelectric materials with enhanced reliability and operational lifespan of flexible thermoelectric devices. This review summarizes recent breakthroughs in low-dimensional thermoelectric materials and emerging defect engineering strategies, which offer promising pathways for simultaneously improving both mechanical and thermoelectrical performance. By precisely regulating the relationship between nanostructural design and performance characteristics, new opportunities are emerging for nanostructured semiconductors in flexible thermoelectric applications across wide temperature ranges, from near-ambient to elevated conditions. Full article

Silicon-based thermoelectric (TE) materials are demonstrating advanced capacity in environmental waste heat recovery. However, intrinsically high lattice thermal conductivity hinders the improvement of TE conversion efficiency. In the present work, a study of B₄C composite for in situ nano-inclusions was carried out to enhance the TE properties of p-type Si₈₀Ge₂₀ materials. During sintering, B₄C was demonstrated to form the SiC and B-rich ternary with a SiGe-based matrix, and the in situ formation of diverse nano-inclusions and the B dopant significantly reduced lattice thermal conductivity without deteriorating power factor (PF), weakening the coupling relationship between thermal and electrical transport properties to a certain extent. The carrier concentration of SiGe alloy samples was significantly increased, resulting in a 7.8% enhancement of PF for Si₈₀Ge₂₀B_0.5-(B₄C)_0.3 at 873 K, while a low lattice thermal conductivity of 0.69 W m⁻¹ K⁻¹ is achieved. The optimal ZT is 1.08, which increased ~50% compared to the pristine sample, and an excellent average ${ZT}_{\mathrm{a}\mathrm{v}\mathrm{g}}$ of 0.62 is obtained among recent p-type SiGe-based TE materials’ works. Our research provides a new perspective for the optimization and practical application of p-type silicon germanium TE materials. Full article

Single-walled carbon nanotube (SWCNT) films are potential materials for thermoelectric generators (TEGs) owing to their flexibility and high thermoelectric performance near 300 K. However, they inherently exhibit low mechanical strength and high thermal conductivity. To address these limitations, SWCNT-based composite films were fabricated by combining SWCNTs with varying amounts of an inorganic-blended acrylic emulsion additive. The resulting SWCNT-based composite films exhibited significantly improved mechanical properties, with breaking strain and tensile strength values approximately thirty and two times higher, respectively, than those of the additive-free SWCNT film. Thermal conductivity decreased from 7.3 W/(m·K) for the additive-free SWCNT film to 2.1 W/(m·K) for the SWCNT-based composite films. Two types of TEGs were fabricated using the composite films: (1) the water-floating TEG, which generated a temperature difference through evaporative cooling; and (2) the standard TEG, which generated a temperature difference when vertically mounted on a heater. The output voltage of the first type of TEGs decreased as the additive amount increased, owing to reduced evaporative cooling. However, the second type of TEGs increased the output voltage by adding the appropriate amount of additive owing to the film’s low thermal conductivity. These findings are significantly helpful in using TEGs with appropriate designs and placements. Full article

This paper delves into the impact of Y doping on In₂O₃ thermoelectric materials. Yttrium doping significantly modifies the properties of In₂O₃, with far-reaching implications for its thermoelectric performance and mechanical characteristics. In the electrical domain, Y³⁺ substitution for In³⁺ optimizes carrier concentration and mobility. The alteration of the electronic band structure leads to a balanced improvement in the Seebeck coefficient and electrical conductivity, boosting the power factor. Despite initial lattice distortion-induced mobility changes, carrier screening at suitable doping levels counteracts this, enhancing overall electrical conductivity. Regarding thermal conductivity, multiple factors act synergistically. Lattice distortion, along with the generation of point defects, dislocations, nanostructuring, and modulated electron–phonon interactions, jointly reduce heat transfer. This reduction is vital for maintaining a substantial temperature gradient, a prerequisite for efficient thermoelectric conversion. The observed increase in ZT (the thermoelectric device figure of merit) with the highest value from ~0.055 to ~0.275. Full article

Long-endurance hypersonic vehicles face the dual challenge of withstanding extreme aerodynamic heating while meeting onboard power requirements. Integrating thermoelectric generators within thermal protection systems offers a solution by converting thermal loads into electrical power. However, accurate prediction requires resolving coupled multiphysics, where three-dimensional simulations are computationally prohibitive and existing one-dimensional models lack accuracy. This study develops a quasi-two-dimensional distributed thermal network incorporating shape-factor corrections for rapid, high-fidelity prediction. Multi-objective optimization is performed to balance specific power, thermal expansion mismatch, and thermal margin. Analysis reveals fundamental trade-offs: a maximum-power design achieves 28.1 W/kg but only a 0.8% thermal margin, whereas a balanced design delivers 24.5 W/kg with a 5.1% thermal margin and significantly reduced thermal stress. Despite geometric variations, peak conversion efficiency converges to approximately 13%. This indicates that efficiency is primarily governed by material properties, while geometric optimization effectively tunes temperature and thermal strain distributions, providing guidelines for reliable system development. Full article