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Polymer thermoelectric (TE) materials present a promising alternative to actuating low‐power wearable electronics without an additional power source, among which poly(3,4‐ethylenedioxythiophene) (PEDOT):poly(styrenesulfonate) (PSS) is a promising candidate. However, it is too hard and brittle to integrate into wearables seamlessly and comfortably. Herein, PEDOT:PSS‐based TE composites with simultaneous softness and stretchability are fabricated by a water‐borne polyurethane (WPU) and PEDOT:PSS mixture containing the judiciously chosen ionic liquid (IL) and subsequent drop casting. The obtained composites show a stable TE voltage, high stretchability (>500%), ultra‐flexibility, and excellent sensitivity (gauge factor = 1251). More importantly, it exhibited “J‐shaped” stress–strain curves resembling human skins after a loading/releasing treatment. The skin‐like nonlinear elastic behavior combines enough softness in the “toe” region, high stretchability, and a strong strain hardening at the late deformation stage, enabling its seamless and comfortable integration with the human body. Given the desired mechanical performance and strain‐sensing capability, the composite is designed to serve as a self‐powered sensor with high sensitivity and accuracy, suggesting a high potential in human motion detection. This work demonstrates the versatility of the developed skin‐like PEDOT:PSS‐based composites in wearable electronics. [ABSTRACT FROM AUTHOR]

The development of Ga-doped Zinc Oxide (GZO) films from nontoxic, abundant elements using a cost-effective and scalable approach is crucial for the profitability and sustainability of thermoelectric applications. Challenges in formulating GZO film inks have led to extensive experimentation to enhance their thermal, structural, mechanical, and room-temperature thermoelectric properties by adjusting ink concentration and annealing treatment. Increasing the GZO nanoparticle concentration reduced the melting temperature and crystallinity, whereas annealing at 200 °C decomposed the polyethylene oxide (PEO) binder. TEM analysis revealed the polycrystalline structure of the GZO nanoparticles and their interaction with the binder, while XRD patterns confirmed the characteristic peaks of the GZO films; annealing effectively eliminated the PEO diffraction peaks. The GZO films from the concentrated 1.24M ink exhibited minimal grain growth, reduced lattice strains, uniform elemental distribution, and enhanced surface texture and conductivity, which were further improved by annealing. Increasing the GZO nanoparticle concentration facilitated the formation of a conductive network, while annealing enhanced the conductivity by promoting the formation of a cohesive, interconnected network through impurity removal, nanoparticle redistribution, and coalescence. Consequently, the annealed 1.24M film demonstrated the highest nanohardness of 791 MPa and a thermoelectric power factor of 1.78 nW/m∙K2 at room temperature, which were attributed to enhanced electrical conductivity and Seebeck coefficient through concentration and annealing synergies. [ABSTRACT FROM AUTHOR]

Besides excellent thermoelectric properties, composed of earth-abundant elements and featuring simple chemical compositions are more conducive to the practical fabrication and utilization of thermoelectric materials. In this study, a tellurium-free thermoelectric compound, AgSbSe 2 , was synthesized, and the impact of Ag deficiencies on its thermoelectric performance was examined. It was found that the density of charge carriers of AgSbSe 2 can be effectively modulated by introducing slight Ag deficiencies, thereby significantly optimizing its electrical transport performance. A peak power factor of 6.63 μWcm−1K−2 @623 K is achieved in the sample with a composition of Ag 0.99 SbSe 2 , which is similar to the maximum value observed in Pb doped samples prepared by the same experimental production. Meanwhile, extremely low thermal conductivity was restrained in AgSbSe 2 with Ag deficiencies due to the effect of phonon scattering caused by crystal defects, which offsets the increased electrical thermal conductivity. Finally, a maximum zT value of 0.97 @623 K is obtained for Ag 0.99 SbSe 2 , which is comparable to that of heavily doped AgSbSe 2 with the conventional divalent cations doping at the Sb site. [ABSTRACT FROM AUTHOR]

High-pressure effects can be used to effectively optimize the thermoelectric performance of wide-bandgap oxides. We build upon this finding to show that the synergistic effects of doping with aluminum and graphene composite give excellent thermoelectric performance under high pressure. By employing the parabolic band model, the Pisarenko curves are derived at different pressures, coupled with the band structure of Al-doped ZnO. An analysis indicates that pressure-induced narrowing of the bandgap in Al-doped ZnO reduces the electron excitation energy, thereby optimizing the electrical properties of the samples. The Debye Callaway model is also used to fit the lattice thermal conductivity of the samples, thus enabling an in-depth analysis of the phonon scattering mechanisms. Our analysis suggests that graphene composites significantly enhance point defect scattering and Umklapp scattering, thus increasing the phonon relaxation time and effectively reducing the lattice thermal conductivity of the samples. The improvement in the figure of merit (zT) of ZnO is attributed to the simultaneous enhancement of its electrical properties under high pressure and the synergistic optimization of reducing the lattice thermal conductivity through doping and composites. In this work, we consider a fixed doping ratio of Al and a constant proportion of graphene composite, and analyze the microstructure and thermoelectric properties of 0.1C–ZnAl 0.04 O (C–ZnAlO) samples synthesized under pressures ranging from 1 to 5 GPa, with the aim of elucidating the influence of pressure and graphene composite on the electro-acoustic transport properties of ZnO. We find that the zT value for a sample synthesized at 5 GPa is increased to 0.27 at 973 K. [ABSTRACT FROM AUTHOR]

GeTe has been considered as a promising mid‐temperature thermoelectric (TE) candidate, but its zT value is severely limited by the excessive hole concentration and high thermal conductivity. Here, it is demonstrated that the TE properties of GeTe can be significantly improve by defect engineering of Sb‐Pb and AgCuTe codoping. The Sb‐Pb codoping is adopted to optimize the carrier concentration and manipulate the rhombohedral lattice distortion, leading to valence band convergence and enhanced power factor. The AgCuTe alloying introduces multiscale phonon scattering centers including dislocations and nano‐precipitates to reduce the lattice thermal conductivity in GeTe. Consequently, a maximum zT of 2.3 at 773 K and an average zT of 1.43 (300–773 K) are obtained in (Ge0.84Sb0.06Pb0.1Te)0.99(AgCuTe)0.01. Moreover, the fabricated thermoelectric module exhibits a high output power density of 0.59 W cm–2 and an energy conversion efficiency of 7.9% at ΔT = 500 K, suggesting hierarchical defect engineering is an effective strategy to realize high‐performance GeTe‐based thermoelectric. [ABSTRACT FROM AUTHOR]

Inherent in humans is the capacity to perceive music and art, engaging both the visual and auditory senses, with profound effects on physiological and psychological states. Sound and light possess the remarkable ability to transform into thermal energy and, ultimately, electrical signals, playing a crucial role in human sensory perception. This research introduces a previously unmentioned synesthesia‐inspired image and sound recognition system, diverging from conventional image/sound acquisition techniques based on photo/mechanical‐electrical conversion. Leveraging the photo/acoustic‐thermal‐electric effects, the system utilizes micro‐/commercial thermoelectric devices as a conduit for energy conversion. It successfully discriminates monochromatic red, green, blue (RGB) and color coverage, showcasing its proficiency in distinguishing ten digital paintings. Additionally, by probing fiber responses to varied sound frequencies and loudness levels, the system achieves time‐domain identification of four classical music compositions. The device exhibits high sensitivity to detecting input energy and its inputting rate power, offering a novel approach to image and sound recognition through thermal signals. Potential applications span from bionic image sensors and time‐domain thermal monitoring of audio. With further exploration, this thermoelectric‐based system holds promise in quantifying emotional responses to images and sound. [ABSTRACT FROM AUTHOR]

Structural, electronic, magnetic and optical properties of Cu4Mn2Te4 have been reported earlier by the authors, and here, the transport properties of the same are discussed along with the band structure investigation of the neodymium-doped cubic material LMO (LiMn2O4), namely LiMn 1. 7 5 Nd 0. 2 5 O4 compound, under spin polarized schemes through the First Principles calculations. The Full Potential-Linearized Augumented Plane Wave Method (FP-LAPW) method is adopted to investigate the electronic structures based on the framework of Density Functional Theory (DFT). Exchange potentials are treated using the Generalized Gradient Approximations (GGA). Cohesive energy calculations reveal that the ferromagnetic phase of LiMn 1. 7 5 Nd 0. 2 5 O4 and the antiferromagnetic phase of Cu4Mn2Te4 exhibits a stable phase. Of these, FM-LiMn 1. 7 5 Nd 0. 2 5 O4 shows a semi-metallic-like behavior in spin-up channel and metallic behavior in spin-down channel whereas antiferromagnetic Cu4Mn2Te4 exhibits a band gap in both spin-up and spin-down channels. Dirac points are identified at −0.0625 eV in the band structure plot of FM-LiMn 1. 7 5 Nd 0. 2 5 O4 at its high symmetry points Γ and W which is an indication of high electron mobility at ambient condition. The presence of flat and dispersive bands around the Fermi energy level is an indication of high thermopower, and it is present in both the compounds FM-LiMn 1. 7 5 Nd 0. 2 5 O4 and AFM-Cu4Mn2Te4. From the present computations, at 300 K, a power factor range of ( S 2 σ scaled by relaxation time in μ W/msK2) 1. 7 5 × 1 0 2 0 ↑ and 9. 3 7 × 1 0 2 1 ↓ is obtained for ferromagnetic LiMn 1. 7 5 Nd 0. 2 5 O4 compounds at up and down spins, respectively. A typical power factor (μ Wm − 1 s − 1 K − 2 ) of 4. 7 9 × 1 0 1 5 ↑ and 2. 9 7 × 1 0 1 8 ↓ is obtained for antiferromagnetic Cu4Mn2Te4 at 325 K required for good thermoelectric performance. [ABSTRACT FROM AUTHOR]

Thermoelectric generators held great promise through energy harvesting from waste heat. Their practical application, however, is greatly constrained by poor raw material utilization and tedious processing in fabricating desired shapes. Herein, a state‐of‐the‐art process is reported for 3D printing the half‐Heusler (Nb0.88Hf0.12FeSb) thermoelectric material using laser powder bed fusion (LPBF). The multi‐dimensional intra‐ and inter‐granular defects created by this process greatly suppress thermal conductivity by providing numerous phonon scattering centers. The resulting LPBF‐fabricated half‐Heusler exhibits a high figure of merit ≈1.2 at 923 K and a single‐leg maximum efficiency of ≈3.3% at a temperature difference (ΔT) of 371 K. Hafnium oxide nanoparticles generated during LPBF effectively prevent crack propagation, ensuring competent mechanical performance and reliable thermoelectric output. The findings highlight the significant potential of LPBF in driving the next industrial revolution of highly efficient and customizable thermoelectric materials. [ABSTRACT FROM AUTHOR]

Conjugated microporous polymers (CMPs) are characterized by high physical and chemical stabilities along with low thermal conductivities due to their conjugated microporous frameworks, making them promising candidates for thermoelectric application. However, the advancement of CMPs within the thermoelectric field is considerably hampered by their inadequate electrical conductivity and unfavorable processability. Herein, highly‐conducting carbon nanotubes (CNTs) are dispersed in two solvents (1,2‐dichlorobenzene and N‐methyl‐2‐pyrrolidone) to fabricate p‐ and n‐type CNT/CMP nanohybrids. Additionally, two unique CMPs are synthesized to elucidate the impacts of the chemical structures and pore architectures on the thermoelectric properties of the nanohybrids. Finally, due to the differing steric hindrance effects of the two CMPs, the thermoelectric performance can be tuned under varying circumstances. The synergetic effects of low thermal conductivity and efficient dispersion capability of the CMPs yield optimized figure of merit (zT) values of 0.053 and 0.13 at 303 K for the p‐ and n‐type thermoelectric nanohybrids, respectively. This investigation presents an alternative approach to building high zT p‐ and n‐type thermoelectric CNT/CMP nanohybrids operating near ambient temperature via the solvent doping effect and chemical structure design of the CMPs, thereby establishing CMP‐based materials as promising candidates for thermoelectric application. [ABSTRACT FROM AUTHOR]

Bimode temperature‐pressure sensors hold significant promise in personal health monitoring, wearables and robotic signal detection. Traditional bimode sensors typically combine two independent sensors, leading to fabrication complexity. This study develops a bimode temperature‐pressure sensor by using a facile electrodeposition method to create sandwiched BiSbTe/Carbon Paper/BiSbTe thin films and stacking them to a vertical structure. It demonstrates high sensitivity for temperature sensing, capable of detecting temperature difference as low as 1 K, and a rapid response time of 0.92 s due to a vertical structure. Utilizing its thermoelectric mechanism, the sensor achieves self‐powered sensing for finger touch and respiration states. Furthermore, its island‐like contact surface ensures high sensitivity with an extremely fast response time of 0.17 s, by rapidly changing contact resistance under pressure, allowing it to detect various human behaviors, including body movements and micro‐expressions. Beyond its sensing capabilities, the film excels in flexibility, electromagnetic interference shielding, and stability, presenting significant potential for integration into self‐powered electronic skin systems for health monitoring, wearables, artificial intelligence, and other electronic skin applications. [ABSTRACT FROM AUTHOR]

Composites consisting of two nano-or molecular-scale components tend to exhibit newer properties or characterizations compared to the matrix material. However, they are extremely limited in thermoelectricity due to the difficulty of achieving an extremely homogeneous distribution of the material on such a small scale. In this paper, we successfully prepared a series of composite thermoelectric materials of Sr 0.9 La 0.1 Ti 0.85 Nb 0.15 O 3 /carbon nanotubes (CNTs, with contents of 0.5, 1.5, 2.5, and 5.0 wt%). Highly homogeneous dispersion of CNTs was observed in the strontium titanate oxide (SrTiO 3) matrix prepared via high-temperature and high-pressure (HPHT) synthesis due to the interaction between SrTiO 3 and multi-walled CNTs. The experimental results showed that CNTs were uniformly dispersed in the composite powders synthesized using the HPHT method. Meanwhile, the electrical conductivity increased linearly with the increase in the CNTs content. The power factor reached 684 μWm−1K−2 at 973K with 2.5 wt% CNTs composite concentration. This considerable enhancement is attributed to the increase in the charge carrier concentration as well as the higher electron mobility. In addition, the lattice thermal conductivity was suppressed due to enhanced Umklapp scattering. This ultimately leads to a thermoelectric figure of merit, zT , of 0.33 at 973 K. This work opens a new window on the thermoelectric properties of nanocomposite SrTiO 3 -based thermoelectric materials. [ABSTRACT FROM AUTHOR]

The composition: 10KNbO3-10Fe2O3-50B2O3-30V2O5 (in mol%) is produced using the conventional melt quenching method and their corresponding glass–ceramic nanocomposites were studied. The structural properties of the as-quenched sample and its heat-treated samples were investigated using X-ray diffraction and differential thermal analysis. Density (ρ) was found to decrease with increasing average nanocrystallite size as the molar volume increases. Studies on thermoelectric power have been carried out. The glass–ceramic nanocomposite after 2 h of heating exhibits significant improvement of electrical conductivity. The activation energy (W), polaron radius (rp) and other parameters have been estimated in the non-adiabatic region. The current–voltage (I–V) curve of each sample was measured. A temporal analysis of current & voltage in nonlinear I–V curves show pinched hysteresis loop, which is the memristor's fingerprint. The glass–ceramic nanocomposite after 2 h of heating exhibits a large switching window. The results of the study enable us to predict that they will be helpful for future applications of non-volatile electronic-memory devices. [ABSTRACT FROM AUTHOR]

Thermoelectric (TE) cooling and heating are suitable for blood storage cabinet applications due to their portability, low power consumption, no noise, and being environmentally friendly. The temperature range for blood refrigerated storage is 4.0±2.0 °C then, before the blood is injected into the human body, it must gradually warm up to 37±1.0 °C within 10 minutes. However, it could be sensitive to environmental temperature control. Therefore, this study investigates thermoelectric cooling and heating to explore the temperature performance under various case studies, including operational voltages during cooling and heating, ambient temperature, and the load of the blood storage cabinet. The results demonstrated that the blood heater/cooler system can cool to 4.0 °C for 12 V power input and heat up to 37 °C for 3.0 to 4.0 V power input. It verifies that our novel thermoelectric system design can be applied in the blood storage cabinet. [ABSTRACT FROM AUTHOR]

Providing self-powered energy for wearable electronic devices is currently an important research direction in the field of thermoelectric (TE) thin films. In this study, a simple dual-source magnetron sputtering method was used to prepare Ag2Te thin films, which exhibit good TE properties at room temperature, and the growth temperature and subsequent annealing process were optimized to obtain high-quality films. The experimental results show that films grown at a substrate temperature of 280 °C exhibit a high power factor (PF) of ~3.95 μW/cm·K2 at room temperature, which is further improved to 4.79 μW/cm·K2 after optimal annealing treatment, and a highest PF of ~7.85 μW/cm·K2 was observed at 200 °C. Appropriate annealing temperature effectively increases the carrier mobility of the Ag2Te films and adjusts the Ag/Te ratio to make the composition closer to the stoichiometric ratio, thus promoting the enhancement of electrical transport properties. A TE device with five legs was assembled using as-fabricated Ag2Te thin films. With a temperature difference of 40 K, the device was able to generate an output voltage of approximately 14.43 mV and a corresponding power of about 50.52 nW. This work not only prepared a high-performance Ag2Te film but also demonstrated its application prospects in the field of self-powered electronic devices. [ABSTRACT FROM AUTHOR]

The acrylic polymer composites in this study are made up of various weight ratios of cement or silica nanoparticles (1, 3, 5, and 10 wt%) using the casting method. The effects of doping ratio/type on mechanical, dielectric, thermal, and hydrophobic properties were investigated. Acrylic polymer composites containing 5 wt% cement or silica nanoparticles had the lowest abrasion wear rates and the highest shore-D hardness and impact strength. The increase in the inclusion of cement or silica nanoparticles enhanced surface roughness, water contact angle (WCA), and thermal insulation. Acrylic/cement composites demonstrated higher mechanical, electrical, and thermal insulation properties than acrylic/silica composites because of their lower particle size and their low thermal/electrical conductivity. Furthermore, to improve the surface hydrophobic characteristics of acrylic composites, the surface was treated with a dielectric barrier discharge (DBD) plasma jet. The DBD plasma jet treatment significantly enhanced the hydrophobicity of acrylic polymer composites. For example, the WCA of acrylic composites containing 5 wt% silica or cement nanoparticles increased from 35.3° to 55° and 44.7° to 73°, respectively, by plasma treatment performed at an Ar flow rate of 5 L/min and for an exposure interval of 25 s. The DBD plasma jet treatment is an excellent and inexpensive technique for improving the hydrophobic properties of acrylic polymer composites. These findings offer important perspectives on the development of materials coating for technical applications. [ABSTRACT FROM AUTHOR]

The La0.9·0.1MnO2.9 compound were prepared by sol–gel method with the aim of obtaining a material with interesting magnetocaloric and thermoelectric properties. The prepared material crystallized in rhombohedric system with R-3c space group. In the magnetization vs. temperature graph, it is observed a paramagnetic (PM)-ferromagnetic (FM) transition with a Curie temperature TC of 209 K. From the fit of hysteresis cycle at 5 K, it is observed that the dominant contribution is ferromagnetic. A magnetic entropy change, calculated from the isothermal magnetization curves, was observed for the sample with a peak centered on TC. The total electronic density states (TDOS) show the coexistence of metallic behavior for spin-up states and semiconductor characteristic, with a Eg = 1.3 eV, for spin-down states. Thermoelectric properties analysis revealed promising behavior with ZT that assesses the efficacy of a compound in a thermoelectric field, reaching 1.1 at 420 K. [ABSTRACT FROM AUTHOR]

Ab-initio simulations using density functional theory (DFT) were employed to investigate the structural, mechanical, electronic, magnetic, optical, and thermoelectric properties of halide perovskites (X = Cl, Br, I). Structural optimization and mechanical stability assessments confirm the reliability of these perovskites in a hexagonal P mc symmetry. The stability of the ferromagnetic phase was validated through total crystal energy minimization via Murnaghan's equation of state. Electronic band structures and density of states, derived from the generalized gradient approximation (GGA), reveal a semiconducting ferromagnetic nature in the spin up channel, spotlighting their potential in semiconductor spintronic applications. Phonon dispersion analysis of and revealed positive phonon modes throughout the entire Brillouin zone, confirming their dynamical stability. In contrast, demonstrated dynamical instability. The elastic constants confirm the mechanical stability and ductile nature of the perovskites. Optical and dielectric properties of these perovskites show significant UV absorption and photoconductivity, making them highly suitable for optoelectronic and solar cell applications. Finally, transport properties, such as the Seebeck coefficient, electrical conductivity, thermal conductivity, power factor, and figure of merit (ZT) unveil their exceptional thermoelectric performance. Combining half-metallic ferromagnetic traits with superior thermoelectric and optoelectronic performance positions compounds as exceptional candidates for applications in spintronics, optoelectronics, and thermoelectrics. This comprehensive investigation demonstrates their ability to excel across a diverse array of advanced technological applications. [ABSTRACT FROM AUTHOR]

This research aims to produce and develop semiconducting thermoelectric materials for thermoelectric generators in aerospace applications. In this context, ZnAlGeO powders were synthesized via the sol-gel method using precursor materials and a 20% toluene solution in ethanol as the solvent. Glacial acetic acid was added to accelerate gel formation. The pH and turbidity values of prepared solutions were measured using a pH meter and turbidimeter. After gelation, the obtained xerogel was dried at 200 °C for 9 h to remove moisture and undesired gases. Dried powders were calcined at 600 °C for 4 h in air, resulting in final ZnAlGeO materials. The pellets underwent thermal processing for 36 h at a temperature of 1350 °C, targeting the production of bulk samples within the n-type semiconductor category. Extensive characterization, including thermal, structural, microstructural, and thermoelectric properties, was conducted using various techniques such as DTA-TG, FTIR, XRD, XPS, SEM, and thermoelectric measurement devices. The study concludes that the produced semiconducting ceramic materials exhibit efficiency for thermoelectric generator production. Highlights: Zn1-x-yAlxGeyO (x = 0.02, 0.04, and y = 0.02, 0.04) powders were synthesized by sol-gel method and densified under high-pressure cold pressing. Effects of dual doping on thermoelectric properties of Zn1-x-yAlxGeyO (x = 0.02, 0.04, and y = 0.02, 0.04) were investigated. Thermoelectric performances of Zn1-x-yAlxGeyO (x = 0.02, 0.04, and y = 0.02, 0.04) are enhanced by dual doping. Promising Zn1-x-yAlxGeyO (x = 0.02, 0.04, and y = 0.02, 0.04) oxide materials for energy harvesting and conversion technologies, particularly in aerospace applications. [ABSTRACT FROM AUTHOR]

In this paper we have scrutinized the structural, mechanical, electro-magnetic and thermoelectric properties of CsUO3 perovskite with the help of density functional theory. The ground state stability of the alloy was determined by optimizing their total ground state energies in two different phases which defines that the alloy is stable in ferromagnetic phase. The elastic constants again ensured the stability of the alloy in cubic structure and suggests the ductile nature of the alloy. The electronic profile from GGA and mBJ simulations reflects the half-metallic nature of the alloy. We have studied the thermoelectric response of the material by calculating the different transport parameters. Finally, we have calculated different optical parameters which highlighted the use of this oxide-based perovskite in optoelectronic devices. Considering the above properties suggest the applications of this alloy in solar cells, energy storage devices and various other domains. [ABSTRACT FROM AUTHOR]

Switchable conductivity in elementary semiconducting materials has a high potential for the design of diodes, transistors and energy conversion technologies. However, the ability to utilize their physical properties is dependent on doping within the carrier density transition temperature. Single-crystal tellurium has a high Seebeck coefficient and intrinsic p–n–p conduction at room temperature and therefore, is not suitable for thermoelectric applications. We demonstrate that the addition of isovalent Se lowers the Fermi level to achieve a stable p-type conductivity with a high band degeneracy near the valence band. We observed shifts in the n–p transition temperature below the intrinsic conductivity at 470 K based on changes in stoichiometry and carrier concentration above 1017 cm−3. In addition, the high thermal conductivity is significantly reduced with the increase in Se alloying due to the mass and strain fluctuations. This results in a moderately high zT of 0.4 at 673 K. [ABSTRACT FROM AUTHOR]

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Soft robots have excellent spatial adaptability and high flexibility, but they are limited by the low stiffness of their constituent materials when faced with high‐load tasks. In recent years, there have been many works on the development of stiffness‐tunable soft actuators by introducing variable stiffness materials into soft actuators, but the existing solutions usually suffer from the problems of slow response, complex structure, and the need of many auxiliary devices to support the completion of the stiffness tuning cycle. This paper proposes a tendon‐driven stiffness‐tunable soft actuator that addresses these issues. Benefiting from the bidirectional temperature control of thermoelectric modules and the excellent in‐plane thermal conductivity of graphene, the actuator is capable of achieving the heating and cooling process by transferring the heat flow through the graphene structure into and out of the shape‐memory polymer (SMP) layer of the tendon‐driven actuator. This enables stiffness tuning via a single device, reducing the dependence on complex external cooling systems. The use of tendon‐driven actuators further eliminates the complex bellow structure of conventional pneumatic actuators and dramatically reduces the size and manufacturing difficulty of individual actuators. Finally, the high load capacity and shape adaptability of the actuator are demonstrated by a gripper equipped with three actuators, which successfully grips objects of various shapes and weights, ranging from less than 10 g to up to 1.6 kg. [ABSTRACT FROM AUTHOR]

Thermoelectric energy conversion technology is considered as one of the most promising solutions for recovering waste heat generated by fossil fuel combustion. As typical types of thermoelectric materials in the middle and high‐temperature range (500–900 K), binary IV‐VI (IV = Ge, Sn, Pb; VI = Se, Te) compounds are extensively studied. Lately, the obtained high‐performance thermoelectric solid solutions between IV‐VI and I‐V‐VI2 (I = Li, Na, K, Ag, Cu; V = Sb, Bi; VI = S, Se, Te) compounds have brought those complex chalcogenides back to the central point of thermoelectric community due to the emerging rich physical phenomena. Profiting from this effective approach, unveiling the underlying mechanism and understanding of alloying effect on the transport properties of these solid solutions becomes particularly significant. This review presents the latest progress in designing high‐performance IV‐VI/I‐V‐VI2 solid solutions and the underlining physical mechanisms, in which detailed discussion about the role of I‐V‐VI2 compounds play in optimizing individual properties of IV‐VI materials is made. This comprehensive review highlights the multiple effects of I‐V‐VI2 alloying on thermoelectric properties of IV‐VI compounds and will drive the related research interests aiming at developing new‐generation thermoelectric compounds in this family. [ABSTRACT FROM AUTHOR]

Tin sulfide (SnS)  has been developed as an earth‐abundant and eco‐friendly compound that exhibits promising thermoelectric (TE) performance. While significant achievements are achieved in p‐type SnS, the development of its n‐type counterpart remains at a nascent stage, making it rather essential for developing n‐type SnS to ensure good compatibility in SnS‐based TE devices. In this study, Br is selected as the aliovalent dopant for realizing n‐type transport in SnS. Subsequently, isoelectronic Se alloying and vacancy compensation are utilized to further promote the TE performance for n‐type SnS. Se alloying can effectively narrow the bandgap of SnS for enhancing carrier concentration and diminishing thermal conductivity by strain and mass field fluctuations, while the excess Sn further compensates intrinsic Sn vacancies, thus optimizing carrier concentration and mobility simultaneously. These results are well verified by microstructure characterization and defect formation energy calculations. Consequently, the maximum ZT value of ≈0.7 and quality factor B of ≈1.02 at 823 K can be obtained after stepwise optimization, which is currently the highest value for n‐type SnS thermoelectrics. This study presents a significant progress for n‐type SnS and lays an important foundation for constructing all‐SnS‐based TE devices. [ABSTRACT FROM AUTHOR]

Thermoelectric (TE) materials are significant for sustainable development because they can be used to harvest waste heat into electricity. Organic TE materials have unique merits including high mechanical flexibility, low cost, and low intrinsic thermal conductivity. But their TE properties particularly the Seebeck coefficient are notably lower than the inorganic counterparts. Here, a poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) film is reported with a very high Seebeck coefficient and figure of merit (zT) at room temperature through secondary doping, dedoping engineering, and ionic energy filtering. The PEDOT:PSS films are successively treated with acid, base, and vitamin C that is a reductant, and then coated with 1‐ethyl‐3‐methylimidazolium dicyanamide (EMIM:DCA) that is an ionic liquid. This can exhibit a record‐high Seebeck coefficient and power factor of 111 µV K−1 and 1285 µW m−1 K−2, respectively, and the corresponding zT value is 1.05. This is the highest zT value for polymers and polymer composites, and it is comparable to that of the best inorganic TE materials. [ABSTRACT FROM AUTHOR]

Higher Manganese Silicides (HMS) are the best p-type materials beneficial for intermediate-temperature range thermoelectric device applications due to their high thermal stability and inexpensive constituent elements. Although the cost-effective HMS materials possess high thermal stability, they are concerned with high thermal conductivity values. The nanocomposite approach was promised to lower the thermal transport properties without affecting the electrical transport properties, which is experimented in the present work. The higher manganese silicide with varying weight percentages of nano-structured Si 0.8 Ge 0.2 B 0.02 inclusions was experimented to decrease the thermal conductivity and to enhance the electrical properties. The lowest thermal conductivity value of ≃ 2.24 W/mK was reported with 2 wt% Si 0.8 Ge 0.2 B 0.02 addition in HMS material. Also, the HMS-2 wt. % Si 0.8 Ge 0.2 B 0.02 improved the transport properties, electrical conductivity and Seebeck coefficient values of ≃ 4 × 104 S/m and ≃ 220 μV/K respectively. Furthermore, various mathematical models were proposed here to simulate the composite approach results, which were then correlated with experimental results. [ABSTRACT FROM AUTHOR]

Since crystal structure dictates the resultant physical properties of materials, titled physical features of the P21 monoclinic SiGe semiconductors, which are still unclear, have been revealed by density functional theory (DFT). The electronic band gap value with 0.49 eV was found to be in the order of previously published cubic and hexagonal closed-packed SiGe semiconductors. Surprisingly, P21 monoclinic SiGe has a room temperature Seebeck coefficient of 1500 μ V/K which is higher than the reported data of both cubic and hexagonal SiGe alloys. Further, the mechanically stable P21 monoclinic phase of the SiGe displays a brittle mechanical character with clear elastic anisotropy has also been deduced. The P21 monoclinic phase of the SiGe can be also considered a good high-dielectric material and beneficial for practical applications of IR or UV goals due to its high refractive index. [ABSTRACT FROM AUTHOR]

First-principles simulations are conducted to explore the structural stability, electronic properties, and optical responses of pristine and boron- or nitrogen-doped monolayers graphene. The computed electronic density of states revealed that the substitutional doping of boron impurity atoms on monolayer graphene (MLG) shifts the Dirac point upward, although the substitution of nitrogen impurity atoms in graphene pushes the Dirac point downward the Fermi level. This could exhibit that upon the doping of MLG with boron or nitrogen, respectively, p-type or n-type semimetal is acquired. The overall optical spectral properties of the substituted graphene with boron or nitrogen atoms are simulated and compared with the optical spectra results of pure graphene. The optical features of pristine and doped MLG are determined by taking the interband and intra-band transitions into account ranging from the far-infrared to the ultraviolet regime of the electromagnetic radiation. A remarkable red shift in the optical spectra of the doped MLG towards the visible regime of radiation is established. An enhanced reflectivity illustrated that concentration-dependent optical properties of boron and nitrogen-doped MLG happen at lower electromagnetic radiation regimes. In addition, we explored the thermoelectric behaviors of the pristine/doped graphene monolayers with 4 × 4 supercells. We found a significant improvement in the electrical conductivity of graphene when doped with boron or nitrogen impurities. However, an increase in the electrical conductivity has textured a decrease in the Seebeck coefficients. Improvement in the electrical conductivity is attributed to an interesting effect on the graphene monolayers' power factor (PF). These findings indicate a positive impact of the dopants on the thermoelectric properties of graphene monolayers and reveal that they are potential materials for thermoelectric applications and nanodevices. [ABSTRACT FROM AUTHOR]

The rapid advancement of Internet of Things (IoT) technology and AI microchips has increased the demand for efficient and cost‐effective cooling solutions. However, traditional Bi2Te3‐based thermoelectric modules face the challenge of low abundance tellurium (Te). Although Te‐free modules using MgAgSb have been explored, they still suffer from a low price‐to‐performance ratio. To address these issues, this study investigates the development of alternative thermoelectric materials that are both cost‐effective and Te free. In this work, the potential of cost‐effective Te‐free alternatives is explored for thermoelectric applications by developing a high‐performance module composed of amorphous carbon‐modulated Mg3(Bi,Sb)2 and electron‐poor CdSb. The modules of CdSb/Bi2Te3 and CdSb/Mg3(Bi,Sb)2 demonstrate superior refrigeration performance, achieving a maximum temperature difference (ΔTmax) of 49.2 and 46 K, respectively. Notably, the material cost of CdSb/Mg3(Bi,Sb)2 module is only 5.5% of Te‐free modules built on MgAgSb, highlighting a significant economic advantage. This work provides a viable, ultralow‐cost approach to meet general refrigeration needs, thereby enhancing the practical value and application potential of thermoelectric materials. [ABSTRACT FROM AUTHOR]

Thermoelectric (TE) fibers are more suitable than films for portable or wearable devices. Herein, 2–3 nm thick poly (3,4‐ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT:PSS) layer‐coated tellurium nanowires (PC‐Te NWs) are in situ prepared by a hydrothermal method. Then a series of PEDOT: PSS/PC‐Te NWs composite fibers are prepared by wet spinning and post‐treatment. The nanolayer prevents the agglomeration of the Te NWs and makes the NWs and PEDOT:PSS matrix have good compatibility, which results in the PC‐Te NWs content to a high value of 70 wt% and the fibers still with flexibility. The high aspect ratio of the PC‐Te NWs and the stress from the inner wall of the needle during spinning make the NWs ordered align along the composite fiber. Due to the large content and orientational arrangement of the PC‐Te NWs, as well as effective post‐treatment, an optimized composite fiber shows a power factor of 385.4 µW m−1 K−2 at 300 K, which is ≈4.9 times as high as the highest value of previously reported PEDOT:PSS/Te NWs‐based composite fibers. In addition, the composite fiber has good flexibility. The flexible TE generators assembled have excellent output performance. This work provides an effective strategy for the preparation of high‐performance flexible TE composite fibers. [ABSTRACT FROM AUTHOR]

Dislocations as line defects in crystalline solids play a crucial role in controlling the mechanical and functional properties of materials. Yet, for functional ceramic oxides, it is very difficult to introduce dense dislocations because of the strong chemical bonds. In this work, the introduction of high‐density dislocations is demonstrated by ultrahigh‐pressure sintering into a typical ceramic oxide, BiCuSeO, for thermoelectric applications. The ultrahigh‐pressure induces shear stresses that surpass the critical strength for dislocation nucleation, followed by dislocation glide and profuse multiplication, leading to a high dislocation density of ≈9.1 × 1016 m−2 in Bi0.96Pb0.04CuSeO ceramic. These dislocations greatly suppress the phonon transport to reduce the lattice thermal conductivity, reaching 0.13 Wm−1 K−1 at 767 K and resulting in a record‐high zT of 1.69 in this oxide thermoelectric ceramic. This study demonstrates the feasibility of generating dense dislocations in ceramic oxides via ultrahigh‐pressure sintering for tuning functional properties. [ABSTRACT FROM AUTHOR]

Thermoelectric Peltier coolers (PCs) are being increasingly used as temperature stabilizers for optoelectronic devices. Increasing integration drives PC miniaturization, requiring thermoelectric materials with good strength. We demonstrate a simultaneous gain of thermoelectric and mechanical performance in (Bi, Sb)2Te3, and successfully fabricate micro PCs (2 × 2 mm2 cross-section) that show excellent maximum cooling temperature difference of 89.3 K with a hot-side temperature of 348 K. A multi-step process involving annealing, hot-forging and composition design, is developed to modify the atomic defects and nano- and microstructures. The peak ZT is improved to ∼1.50 at 348 K, and the flexural and compressive strengths are significantly enhanced to ∼140 MPa and ∼224 MPa, respectively. These achievements hold great potential for advancing solid-state refrigeration technology in small spaces. [ABSTRACT FROM AUTHOR]

The prototype phonon-liquid electron-crystal β-Cu2Se has been recognized as one of the top-performing thermoelectric materials due to its ultralow lattice thermal conductivity (κ). This paper reports the synthesis of Telluride-doped Bi0.001Cu2Se through the combination of ball milling and spark plasma sintering. The thermoelectric properties of the materials, encompassing electrical resistivity, Seebeck coefficient, and thermal conductivity within the temperature range of 300 K to 873 K, have been evaluated. The Bi0.001Cu2Se0.90Te0.10 sample exhibited a peak Seebeck coefficient of 192.6 μV/K, which is approximately 23.5% higher than that of the bulk Bi0.001Cu2Se alloy. Both Bi0.001Cu2Se and Bi0.001Cu2Se0.90Te0.10 demonstrated comparable high power factors of 1221.9 μWm− 1K− 2 and 1223.6 μWm− 1K− 2, attributed to their moderate electronic conductivity and Seebeck coefficient. The porous Bi0.001Cu2Se0.80Te0.20 samples exhibited a minimum thermal conductivity of 0.61− 1 K− 1 at 873 K, representing a reduction of up to 21.8% compared to the bulk Bi0.001Cu2Se alloy. This decrease in thermal conductivity can be attributed to the boundaries and defects formed during the spark plasma sintering process, as well as the porous nature of the samples. The figure of merit for the Bi0.001Cu2Se0.80Te0.20 was found to have a maximum value of approximately 1.49 at 873 K, primarily due to its significantly lower thermal conductivity. [ABSTRACT FROM AUTHOR]

BiCuSeO is a promising oxygen‐containing thermoelectric material due to its intrinsically low lattice thermal conductivity and excellent service stability. However, the low electrical conductivity limits its thermoelectric performance. Aliovalent element doping can significantly improve their carrier concentration, but it may also impact carrier mobility and thermal transport properties. Considering the influence of graphene on carrier‐phonon decoupling, Bi0.88Pb0.06Ca0.06CuSeO (BPCCSO)‐graphene composites are designed. For further practical application, a rapid preparation method is employed, taking less than 1 h, which combines self‐propagating high‐temperature synthesis with spark plasma sintering. The incorporation of graphene simultaneously optimizes the electrical properties and thermal conductivity, yielding a high ratio of weighted mobility to lattice thermal conductivity (144 at 300 K and 95 at 923 K). Ultimately, BPCCSO‐graphene composites achieve exceptional thermoelectric performance with a ZT value of 1.6 at 923 K, bringing a ≈40% improvement over BPCCSO without graphene. This work further promotes the practical application of BiCuSeO‐based materials and this facile and effective strategy can also be extended to other thermoelectric systems. [ABSTRACT FROM AUTHOR]

Sn/S double-doped permingeatites, Cu3Sb1−xSnxSe4−ySy (0.02 ≤ x ≤ 0.08 and 0.25 ≤ y ≤ 0.50) were synthesized, and crystallographic parameters and thermoelectric characteristics were examined as a function of doping level. The lattice parameters of permingeatite were significantly modified by the dual doping of Sn and S, with S doping exerting a greater influence on lattice constants and variations in tetragonality compared to Sn doping. With an increase in the level of Sn doping and a decrease in S doping, the carrier concentration increased, leading to enhanced electrical conductivity, indicative of a degenerate semiconducting state. Conversely, an increase in S doping and a decrease in Sn doping led to a rise in the Seebeck coefficient, demonstrating p-type conductivity characteristics with positive temperature dependence. Additionally, the double doping of Sn and S substantially improved the power factor, with Cu3Sb0.98Sn0.02Se3.75S0.25 exhibiting 1.12 mWm−1K−2 at 623 K, approximately 2.3 times higher than that of undoped permingeatite. The lattice thermal conductivity decreased with increasing temperature, while the electronic thermal conductivity exhibited minimal temperature dependence. Ultimately, the dimensionless figure of merit (ZT) was improved through the double doping of Sn and S, with Cu3Sb0.98Sn0.02Se3.50S0.50 recording a ZT of 0.68 at 623 K, approximately 1.7 times higher than that of pure permingeatite. [ABSTRACT FROM AUTHOR]

Dopant‐induced microstructure in thermoelectric materials significantly affects thermoelectric properties and offers a potential to break the interdependence between electron and phonon transport properties. However, identifying all‐scale dopant‐induced microstructures and correlating them with thermoelectric properties remain a huge challenge owing to a lack of detailed microstructural characterization encompassing all length scales. Here, the hierarchical boron (B)‐induced microstructures in B‐doped Si80Ge20 alloys with different B concentrations are investigated to determine their precise effects on thermoelectric properties. By adopting a multi‐scale characterization approach, including X‐ray diffraction, scanning and transmission electron microscopy, and atom probe tomography, five distinctive B‐induced phases within Si80Ge20 alloys are identified. These phases exhibit different sizes, compositions, and crystal structures. Furthermore, their configuration is comprehensively determined according to B doping concentrations to elucidate their consequential impact on the unusual changes in carrier concentration, density‐of‐states effective mass, and lattice thermal conductivity. The study provides insights into the intricate relationship between hierarchical dopant‐induced microstructures and thermoelectric properties and highlights the importance of investigating all‐scale microstructures in excessively‐doped systems for determining the precise structure‐property relationships. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) exhibit large surface areas and low thermal conductivity, making them promising for thermoelectric generation. However, their limited electrical conductivity poses a significant hurdle to be practically useful. Traditionally, enhancing the electrical conductivity of MOFs typically comes at the cost of reducing surface area, thereby increasing thermal conductivity. This study introduces an approach to simultaneously boost the electrical conductivity and porosity of a MOF‐based material while maintaining remarkably low thermal conductivity. The electrically conductive poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) is deployed to nucleate the growth of Cu3(BTC)2 (or simply CuBTC, where BTC = benzene‐1,3,5‐tricarboxylic acid), resulting in the synthesis of composites labeled CPP‐y (where y denotes wt% PEDOT:PSS). Predictably, the CPP‐y composites are more electrically conductive than pure CuBTC, achieving an electrical conductivity exceeding 1.40 S cm−1 at room temperature. Furthermore, the CPP‐y composites exhibit consistently high Brunauer–Emmett–Teller (BET) surface areas of ≈1600 m2 g−1, comparable to pristine CuBTC, while maintaining thermal conductivities below 0.04 W m−1 K−1 at room temperature. With a high Seebeck coefficient in the range 180–373 µV K−1, CPP‐15 and CPP‐23 demonstrate a figure‐of‐merit (zT) of 0.25 and 0.11, respectively, at 285 K, marking a substantial achievement for MOF‐based materials. [ABSTRACT FROM AUTHOR]

This article investigates the influence of an electromagnetic field on the surface of an elastic semiconductor material in a scenario where deformation occurs in just one dimension. The problem is solved by employing the two-temperature theory to examine the interactions between plasma and thermoelastic waves in a generalized thermoelastic half-space. The study examines the impacts of changing thermal and electrical conductivity. We examine the influence of the initial hydrostatic stress and a small mechanical strain on a photothermal transfer mechanism. The Laplace transform (LT) technique is employed to compute the constitutive relationships, governing equations, and various parameters of the thermo-electro-magnetic medium. To determine the principal physical parameters in the Laplace domain, the interface close to the vacuum is subjected to mechanical forces, temperature constraints, and plasma boundary conditions. The numerical method is employed to inverse the LT and offer comprehensive solutions in the time domain for the primarily investigated physical phenomena. We have performed a visual examination of how the thermoelectric and thermoelastic properties, as well as two-temperature variables of the applied force, affect the distributions of carrier density, force stress, temperature, and displacement components. [ABSTRACT FROM AUTHOR]

Silver selenide (Ag2Se) is a promising thermoelectric material for near‐room temperature applications. This study proposes a fast, simple, and cost‐effective method for producing high thermoelectric performance bulk Ag2Se. Ag2Se powders were synthesized from Ag and Se powders via a one‐hour wet ball milling process, followed by the fabrication of bulk pellets through low‐temperature hot‐pressing (130–250 °C) with a mere 0.5‐hour holding time. Both Ag2Se powders and bulk pellets exhibited a single phase of Ag2Se with an orthorhombic structure. Moreover, uniform compositional distribution with the stoichiometric Ag : Se ratio was observed in all samples. Microstructural analysis revealed distinct grain boundaries in samples hot‐pressed below 190 °C, transitioning to grain coalescence was at 190 °C and 250 °C. The thermoelectric and transport measurements demonstrated that the electrical conductivity decreased and the Seebeck coefficient increased with hot‐pressing temperatures from 130 °C and 190 °C primarily due to reduced carrier concentrations. Thermal conductivity decreased with increasing hot‐pressing temperatures up to 190 °C, attributed to the weak chemical bonding of Ag2Se and the presence of defects. This combination resulted in a peak zT over 1.0 at 300 K, with an average zT close to 1.0 from 300 to 380 K. In comparison to other reported synthesis methods, the present approach offers significantly reduced processing time, simplicity, and cost‐effectiveness. Despite lower temperatures and shorter processing times, the method produces Ag2Se with zT values comparable to more intricate techniques. This fabrication route holds the potential for scalable mass production in the future. [ABSTRACT FROM AUTHOR]

Organic materials have found widespread applications but require doping to overcome their intrinsically low carrier concentration. Doping injects free carriers into the polymer, moving the position of the Fermi level, and creates coulombic traps, changing the shape of the electronic density of states (DOS). We develop equations to explicitly map the DOS parameters to the Seebeck vs conductivity relationship. At low carrier concentrations, this relationship is a universal slope - k B / q , while at higher carrier concentrations, the slope becomes dependent on the shape of the DOS. We conclude that, at high doping, a heavy-tailed DOS leads to higher thermoelectric power factors. [ABSTRACT FROM AUTHOR]

This work comprehensively studies the electronic, structural, optical, thermodynamic and thermoelectric properties of the Co2CrBi Heusler compound for both ferromagnetic and antiferromagnetic phases. The calculation is based on the Full-potential Linearized Augmented Plane-Wave (FP-LAPW) method by using the "WIEN2k" code, with the Generalized Gradient Approximation (PBE-GGA) for the exchange–correlation potential. The calculations reveal that Co2CrBi exhibits metallic behavior due to the spin polarization at the Fermi level. Further calculations were performed using GGA + SOC + U and hybrid functional HSE06 approximations to confirm this metallic nature. The antiferromagnetic phase is more stable than the ferromagnetic phase, although it cannot be regarded as a hard material. Various properties, including electron energy loss, refractive index, extinction coefficient, optical conductivity, Seebeck coefficient, electrical conductivity, and thermal conductivity are also computed and discussed for both ferromagnetic and antiferromagnetic phases. Additionally, this investigation is extended to encompass the unexplored properties of Co2CrBi, including both thermodynamic and thermoelectric. [ABSTRACT FROM AUTHOR]

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Owing to promising room‐temperature thermoelectric properties, n‐type Ag2Se has been considered as an alternative for Bi2Te3. Herein, a carrier separation strategy is realized by compositing an insulating electron donor, polyethyleneimine (PEI), with the n‐type Ag2Se. Inhomogeneous distribution of PEI can attract the minority carriers (holes) in the n‐type Ag2Se matrix, while the separated minority carriers can avoid significant scattering of the main carriers based on coulomb repulsion, leading to record‐high carrier mobility of 1551.99 cm2 V−1 s−1 and an improved S2σ of 22.39 µW m−1 K−2 at 300 K for 6 mol% PEI/Ag2Se composite film. Moreover, with PEI acting as a binder, the resistance of 6 mol% PEI/Ag2Se composite film only increases by 6.5% after bending 1000 cycles at the radius of 6 mm, showing high stability. The assembled flexible device based on 6 mol% PEI/Ag2Se composite films exhibits an excellent power density of 73.93 W m−2 at a temperature difference of 50 K, showing potential applications in powering generation for wearable electronics. [ABSTRACT FROM AUTHOR]

Silver selenide (Ag2Se) flexible films are promising near‐room‐temperature thermoelectric candidates for low‐grade heat harvesting. However, existing Ag2Se films are generally attached on substrates, which impedes further flexibility improvement of the films and constrains the scenarios of applications. Here a cost‐effective and scalable strategy is presented, which combines screen printing and annealing, for synthesizing freestanding Ag2Se inorganic films with different densities of pores. High‐density pores and thin thickness endow the films with high flexibility, while films with low‐density pores obtain higher power factor. Furthermore, by utilizing the porous microstructure, a composite structure consisting of a Ag2Se conductive network and an organic polydimethylsiloxane (PDMS) skeleton is fabricated, which further improves films’ stability under bending and torsion. Finally, a flexible thermoelectric generator comprising five Ag2Se/PDMS legs and encapsulated PDMS outputs a voltage of 20.2 mV and a maximum power of 810 nW (the corresponding power density is 5.4 W m−2) at a temperature difference of 30 K, verifying potential application at near room temperature. This work offers a useful paradigm for fabricating substrate‐free Ag2Se porous films with high flexibility for near‐room‐temperature thermoelectric applications. [ABSTRACT FROM AUTHOR]

Element doping/alloying is a common strategy to tune the electrical and thermal transports of thermoelectric (TE) materials, but the doping/alloying limit of foreign elements in many TE materials is usually very low, bringing a great challenge to improve the TE performance. In this work, beyond the classic principle of “like dissolves like,” it is found that choosing the compound with a severely distorted lattice and diversified chemical bonding as the matrix also facilitates achieving a high doping/alloying limit. Taking ductile semiconductors as an example, this work shows that gold (Au) element is nearly immiscible in Ag2S and Ag2Te, but has a relatively high alloying limit in complex Ag2S0.5Te0.5 meta‐phase. Au in Ag2S0.5Te0.5 significantly decreases the carrier concentration and improves the TE performance, but scarcely changes the mechanical properties. Consequently, Ag1.99Au0.01S0.5Te0.5 demonstrates both a high figure‐or‐merit of 0.95 at 550 K and extraordinary room‐temperature ductility. This work offers an effective and general strategy to develop stabilized doped/alloyed TE materials. [ABSTRACT FROM AUTHOR]

Copper (Cu)‐based thermoelectric (TE) materials have attracted great attention from both scientific and industrial societies, but for a long time, their real applications are greatly limited by the lack of high‐performance n‐type Cu‐based TE materials. Most recently, the novel n‐type Cu‐based TE material, CuIn5Se8, has been discovered to show a record‐high TE figure‐of‐merit (zT) to match the state‐of‐the‐art p‐type Cu‐based TE materials. However, the physical origin of such high zT is still unclear due to its complex phase compositions and crystal structures. In this work, it is revealed that the excellent TE performance is mainly contributed by the intrinsically ultralow lattice thermal conductivity originating from the unique all‐scale hierarchical architecture. It covers the ranges from atomic‐scale cation disorder in the tetragonal CuIn5Se8 phase and nanoscale diversified stacking units and stacking sequences in the hexagonal CuIn5Se8 phase, to mesoscale grain boundaries between the tetragonal phase and hexagonal phase. Doping Br at the Se‐sites can largely tune the electrical transports of CuIn5Se8 while maintaining the ultralow lattice thermal conductivity, leading to high zT reaching the optimal value predicted by the single parabolic model. This work will guide the investigation of n‐type Cu‐based TE materials in the future. [ABSTRACT FROM AUTHOR]

Photochromic smart windows have drawn increasing attention as an approach to improve building energy efficiency and enhance indoor daylight comfort. However, existing photochromic smart windows still block sunlight from entering the room on sunny winter days, causing additional energy consumption for heating. Herein, a dual‐mode smart window is designed with decoupled photo and thermal functions by combining colorless Fe‐doped WO3 photochromic film with window rotation. Based on this, selective heating and cooling of the room between winter and summer is achieved while maintaining the daylight comfort benefits during all seasons. As a proof of concept, the smart window reduces the temperature of a model house by up to 7.9 °C in summer mode, while in winter mode the temperature is only reduced by 0.7 °C. The proposed seasonally adaptive dual‐mode smart window obtains by window rotation overcomes the limitations of conventional photochromic smart windows, which not only achieves better energy efficiency but also retains improved daylight comfort. Furthermore, it demonstrates that the heat absorbed by the smart window can be harnessed to produce electricity through the integration of thermoelectric modules within the glazing, which enhances its impact on reducing energy consumption. [ABSTRACT FROM AUTHOR]

Manipulating the grain boundary and chiral structure of enantiomorphic inorganic thermoelectric materials facilitates a new degree of freedom for enhancing thermoelectric energy conversion. Chiral twist mechanisms evolve by the screw dislocation phenomenon in the nanostructures; however, contributions of such chiral transport have been neglected for bulk crystals. Tellurium (Te) has a chiral trigonal crystal structure, high band degeneracy, and lattice anharmonicity for high thermoelectric performance. Here, Sb‐doped Te crystals are grown to minimize the severe grain boundary effects on carrier transport and investigate the interface of chiral Te matrix and embedded achiral Sb2Te3 precipitates, which induce unusual lattice twists. The low grain boundary scattering and conformational grain restructuring provide electrical‐favorable semicoherent interfaces. This maintains high electrical conductivity leading to a twofold increase in power factor compared to polycrystal samples. The embedded Sb2Te3 precipitates concurrently enable moderate phonon scattering leading to a remarkable decrease in lattice thermal conductivity and a high dimensionless figure of merit (zT) of 1.1 at 623 K. The crystal growth and chiral atomic reorientation unravel the emerging benefits of interface engineering as a crucial contributor to effectively enhancing carrier transport and minimizing phonon propagation in thermoelectric materials. [ABSTRACT FROM AUTHOR]