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This study aimed to determine various thermoelectric properties, including the dimensionless figure of merit (zT0), resistivity (ρTE), thermal conductivity (κTE), and Seebeck coefficient (S), using a combination of 3ω and time-domain impedance spectroscopy (TDIS) methods for a thermoelectric module at absolute temperature (T0). The effective dimensionless figure of merit (zT0,eff), influenced by heat leakage through attached lead wires, was quantitatively and qualitatively assessed based on the TDIS method. The results demonstrated that zT0,eff/zT0 can be expressed as the ratio between the thermal conductance of the attached thermoelectric element and the lead wire. Thus, by considering heat leakage through the lead wire, the TDIS method can estimate not only zT0 and ρTE but also κTE and S after measuring the lead wire's thermal conductivity using the 3ω method. The study utilized a commercial Π-shaped bismuth-telluride-based thermoelectric module and derived representative values for its elements. zT0, ρTE, κTE, and |S| at 300 K were 0.871, 10.15 μΩ m, 1.71 W/mK, and 224 μV/K, respectively, consistent with previous reports on representative bismuth-telluride-based materials. In conclusion, the combination of the 3ω and TDIS methods is useful for determining all thermoelectric properties, considering heat leakage through attached lead wires. [ABSTRACT FROM AUTHOR]

Different from the extensive experimental investigations into the thermoelectric (TE) properties of the bulk IV–VI compounds, less attention has been paid to the TE properties of the monolayer IV–VI compounds. Here, we consider the TE transport properties including the Seebeck coefficient, electronic conductance, thermal conductance, power factor, and figure of merit Z T of the undoped and Bi-doped GeS monolayers. Our results show that for both the undoped and Bi-doped monolayers the anisotropy is widely observed in all their TE properties, and the maximum Z T at a certain temperature along the armchair direction is much greater than that along the zigzag direction. Moreover, Bi doping can lead to an increase of the maximum Z T , and there are more Z T peaks appearing near the zero chemical potential. This indicates that the Bi-doped GeS monolayer can work as a TE material at a lower bias voltage, and especially along the armchair direction it can work at zero bias voltage, which obviously strengthens the reliability of the TE devices. As the temperature increases, the maximum Z T will be uniformally increased along the armchair and zigzag directions for both the undoped and Bi-doped GeS monolayers. In the temperature scope from 300 to 800 K, the maximum Z T along the armchair direction of the Bi-doped GeS monolayer will increase from 3.39 to 4.85, which indicates that this Bi-doped GeS monolayer is a promising TE material in a wide-temperature zone. As an application, we have designed the GeS-based TE couples and found that their efficiencies can be greater than 27 % at large temperature differences. This research should be an important guidance for designing a low-voltage, wide-temperature-scope, and high-stability TE device. [ABSTRACT FROM AUTHOR]

MXenes exhibit significant potential in thermoelectric materials owing to their exceptional electrical conductivity; however, their limited number of semiconductors restricts their application. Thus, it is highly desirable to expand the MXene family beyond carbides and nitrides to broaden their applications in thermoelectricity. In this work, we systematically investigate the thermoelectric transport of Ti2OX2 (X = F, Cl) MOene through comprehensively evaluating the electron–phonon coupling (EPC) from first principles. Our findings first emphasize the limitations of the deformation potential theory method and stress the importance of considering EPC. Ti2OF2 (Ti2OCl2) monolayer exhibits exceptional electronic transport, with Seebeck coefficients reaching 1483.87 (1206.22) μV/K and electrical conductivity reaching 9.5 × 105 (7.6 × 105) Ω−1 m−1 at room temperature for its N-type counterpart. Additionally, the presence of degenerate multiple valleys and peaks significantly enhances their electronic transport. For phonon transport, EPC results in a significant reduction in lattice thermal conductivity (kL) [e.g., at 300 K with 1.44 × 1015 (1.68 × 1015) cm−2 of hole, the reduction is 86.3% (73.3%) for Ti2OF2 (Ti2OCl2)]. Additionally, their kL demonstrates a strong correlation with the density of states at corresponding Fermi levels. Moreover, the kL and total thermal conductivity of P-type Ti2OF2 show T-independence, making it suitable for applications in aviation and thermal insulation materials. Finally, N-type Ti2OF2 and Ti2OCl2 demonstrate superior zT values of 0.63 and 0.9 at 900 K, respectively. This study provides in-depth insights into the superior thermoelectric properties of Ti2OX2 (X = F, Cl) MOene with considering EPC, providing a novel platform for the next-generation thermoelectric field. [ABSTRACT FROM AUTHOR]

Despite more than seven decades of active research and development in thermoelectricity, the accurate measurement of the thermoelectric (TE) properties of bulk materials has remained a challenge, mainly because of the strong interrelation between thermal and electrical phenomena. This work highlights practical advancements in methods and instrumentation dedicated to the simultaneous measurements of TE properties such as the Seebeck coefficient (S), the thermal (κ), and electrical (σ) conductivities and the dimensionless TE figure of merit ZT = S2σT/κ. The accuracy of a Harman based approach, as implemented by the ZT-Scanner (TEMTE Inc.), applicable to the simultaneous measurement of the above TE properties, has been made possible by a self-contained calibration procedure, which is based on the availability of two samples of the same homogeneous material having different shape factors. It is of practical importance that this approach provides a simple procedure to obtain the calibration for the figure of merit ZT and the thermal conductivity in the temperature interval from 300 to 720 K. In addition, we show that a simplified Harman setup with no thermocouples attached to the sample can also be used for self-contained calibrated ZT measurements. It is concluded that the implemented steady-state approach decreases the relative error down to 1%–2% for ZT measurements and can be recommended for most applications not involving dynamical behavior. In particular, it is proposed that self-generated calibration samples can critically increase the quality and ease of comparison of TE measurements if they are adopted by the TE community. [ABSTRACT FROM AUTHOR]

In this study, we systematically investigated the anomalous Nernst effect in perpendicularly magnetized amorphous TbFeCo thin films with various compositions. It was found that the magnitude of the off diagonal thermopower (ODT), which corresponds to the anomalous Nernst effect, can be uniformly explained with respect to the Tb content regardless of the concentration above or below the compensation composition. The maximum ODT of 1.3 μ V/K and the thermoelectric conductivity of 1.59 A/mK at room temperature were obtained, which is more significant than other perpendicular magnetic anisotropy thin films to achieve a large Nernst voltage for roll-type thermoelectric devices. By considering the thermoelectric tensor, Mott's equation, and the scaling law, it was shown both experimentally and theoretically that the magnitudes of the first and second terms contributing to the anomalous Nernst effect are comparable. It was also found that the ODT of TbFeCo thin films is twice or more significant than the product of the Seebeck coefficient and the Hall angle. Furthermore, amorphous metals and Mn-alloys with a large Berry curvature are located above the relation that the ODT is twice the product of the Seebeck coefficient and the Hall angle, which means that amorphous metals are expected to enhance the ANE. [ABSTRACT FROM AUTHOR]

In this study, the basic properties of Ba2AgSi3 were investigated in detail from both experimental and computational viewpoints. Polycrystalline Ba2AgSi3 formed by an arc-melting apparatus under an argon atmosphere was ground into powders, and then powder samples were sintered using the spark plasma sintering method. Both n-type and p-type samples were obtained. This may be due to a slight deviation from the stoichiometric composition. The energy bandgap of Ba2AgSi3 was measured to be around 0.17 eV from the temperature dependence of electrical conductivity and was in agreement with that by first-principles calculations. Sintered samples exhibited a high Seebeck coefficient of −273 μV K−1 and a high power factor of 0.38 mW m−1 K−2 at 307 K for n-type samples. They were 217 μV K−1 and 0.23 mW m−1 K−2, respectively, at 320 K for p-type samples. The electronic structures of impurity-doped Ba2AgSi3 were also discussed using first-principles calculations to investigate the insertion site of impurity atoms. The calculations suggest that the substitution of B (P) at any Si site shifts the Fermi level and transforms it into p-type (n-type) semiconductors. On the other hand, substitution of Ba or Ag sites with B or P is unlikely to occur in terms of formation energy. [ABSTRACT FROM AUTHOR]

We present an atomistic simulation of thermoelectric properties in cove-edged graphene nanoribbons (CGNRs) via the nonequilibrium Green's function. Different from gapless zigzag graphene nanoribbons (ZGNRs), CGNRs exhibit a noticeable bandgap. Such a bandgap can be modulated by varying three structural parameters (namely, the width N, the distance between adjacent coves m, as well as the shortest offset n) of CGNRs, which can give rise to the transition from semiconducting to semi-metallic. Due to the less dispersive phonon bands and the decrease in the number of phonon channels of CGNRs, they are found to have the lower phonon thermal conductance than ZGNRs. Modulation of CGNRs can produce over tenfold improvement of the maximum of ZT compared to ZGNRs. This improvement is due to the promotion of the Seebeck coefficient together with the degradation of the phonon thermal conductance of CGNRs compared to ZGNRs. [ABSTRACT FROM AUTHOR]

Several glassy oxide semiconductors exhibit large electron mobilities; however, these oxides may not be considered environmentally friendly because of their toxicity. Herein, we report on the electrical conduction of iron oxide-containing bismuth sesquioxide borate glasses that are not toxic and show ohmic transport in the temperature range of 100–400 °C. The dominant carrier is the electron, which is revealed by the signs of Hall and Seebeck coefficients, without sign anomalies. The Hall mobility is ∼0.1 cm2/(V s), and the carrier density is ∼6 × 1015 cm−3 at 400 °C. The Seebeck coefficient is approximately −500 μV/K at 388 °C. The carriers might be generated by charge transfer between Fe2+ and Fe3+ substituted in the glass, and they exhibit thermally activated hopping-type electronic conduction. The oxide glass can be used as a glass thermistor for a temperature range of 100–400 °C. [ABSTRACT FROM AUTHOR]

Organic/inorganic thermoelectric hybrids demonstrate great potential for wearable applications. However, their scalability is hindered by an inferior power factor (S 2 σ). Nowadays, achieving deep optimization of S 2 σ necessitates a strategy to decouple the Seebeck coefficient (S) and electrical conductivity (σ). In this work, we propose a strategy to break the coupling between S and σ by constructing a Schottky interface that exhibits an energy-filtering effect. We validate the feasibility of this approach using a PANI/TiN–TiO2/carbon paper. The results demonstrate a 1.16-fold increase in σ and a 1.08-fold increase in S in PANI/TiN–TiO2/carbon paper achieved through the construction of a Schottky-type TiN/TiO2 interface. The separation of hole/electron at the TiN/TiO2 interface serves as the scattering center for ionized impurity scattering and facilitates the transport pathway for charge carriers. These factors are crucial in determining the simultaneous optimization of S and σ , respectively. Additionally, the energy-filtering effect of the TiN/TiO2 interface plays a positive role in the ionized impurity scattering mechanism by selectively filtering out low-energy carriers. This further strengthens decoupling of the thermoelectric properties. The 14.9% PANI/11.2% TiN–14.5% TiO2/59.44% carbon paper displays the highest S 2 σ and achieves a high ZT value of 223.6 μVm−1 K−2 and 0.31 at 300 K, highlighting the advantages of PANI-based thermoelectric hybrids. This work provides valuable guidance for the design of thermoelectric hybrids incorporating multi-interface morphology. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) materials and their heterostructures have been widely explored for high-performance energy conversion applications. The Thomson effect—a higher order transport process—plays an important role in thermoelectric devices, yet its effect on the performance of thermionic devices remains unknown thus far. Here, we investigate the performance of thermionic refrigeration in vertically stacked heterostructure (VHS) and laterally stitched heterointerface (LHS) composed of a graphene and a 2D semiconductor (i.e., MoS 2 and WSe 2) in the presence of the Thomson effect. Using a temperature-dependent Seebeck coefficient, we derived the analytical expressions of the cooling efficiency and the effective Z T. We shall show that the Thomson effect improves the coefficient of performance (COP) by up to 20%, particularly, in the case where the temperature difference between the cold and the hot electrodes is large. However, the Carnot efficiency decreases with the temperature difference. The overall COP is reduced by the Thomson effect. We calculate the COP in graphene/MoS 2 /graphene and graphene/WSe 2 /graphene VHS and LHS devices. We show that the LHS composed of WSe 2 significantly outperforms the VHS and MoS 2 counterpart. These findings provide an understanding of thermionic processes in the higher-order transport regime and shall offer insights into the design of novel 2D material heterostructure thermionic energy converters. [ABSTRACT FROM AUTHOR]

The contribution of minority charge carriers (electrons) is taken into account in the evaluation of thermo-electromotive force (thermo-E.M.F.) of a non-degenerate p -type semiconductor in the stationary state and when the quasi-neutrality condition is fulfilled. The results obtained show that the contribution to the thermo-E.M.F. due to the presence of minority electrons is a function of the bandgap and the length of the semiconductor used. It also depends on the minority carriers through their electrical conductivity, thermal conductivity, Seebeck coefficient, and bulk and surface recombinations. That contribution tends to reduce the principal thermo-E.M.F. (α p Δ T) of the p -type semiconductor and will, therefore, be called counter-thermo-electromotive force (counter-thermo-E.M.F.). The calculations made in the case of silicon give a counter-thermo-E.M.F. of magnitude generally non-negligible, which decreases when the length of the silicon and the concentration of doping elements increase. Finally, it is shown that the best way to minimize the counter-thermo-E.M.F. is to treat the surface of the semiconductor to promote the recombination of minority carriers there. [ABSTRACT FROM AUTHOR]

The stunning thermoelectric behavior of inorganic/organic hybrids and the lack of information on screen-printed flexible thermoelectric generators based on Cu 3 Se 2 and Polyaniline for low-temperature applications have motivated this work. The synergic influence of various acid dopants, concentration, and annealing temperature of polyaniline on the power density of Cu 3 Se 2 /PANI ink-based flexible thermoelectric generator is explored. The presence of 1.5 wt% of H 2 SO 4 -PANI, annealed at 60 °C, decreased the bandgap and electrical resistance of Cu 3 Se 2 by 11.96 % and 29.4 %, respectively. As a result, an increase of 46.06 % in the Seebeck coefficient and 242 % in the power output is achieved, which is many folds higher than the few reported works using novel materials. In addition, the Cu 3 Se 2 /H 2 SO 4 -PANI ink-based flexible thermoelectric generator with eight legs exhibited a maximum power output, power density, and power factor of 25.69 nW, 23.79 mW/m2, and 0.77 nW/m2K2 at ΔT = 100 °C, respectively under external load. [ABSTRACT FROM AUTHOR]

The layered IVV 2 Te 4 -based compounds have recently received significant attention due to their intrinsically low lattice thermal conductivities. However, the influence of microstructure regulation and halogen doping on their thermoelectric properties has been scarcely studied. In this work, we systematically investigated the anisotropic thermoelectric transport properties of pristine SnSb 2 Te 4 compounds with varied microstructures manipulated by ball milling. With the help of thermoelectric transport models, the optimal ball milling time is estimated based on the calculation of quality factor. Furthermore, the remarkably improved Seebeck coefficient is achieved by the introduction of halogen elements into Te sites, which is attributed to reduced carrier concentration and converged carrier pockets. As a result, a maximal zT ∼0.4 at 725 K is achieved in SnSb 2 (Te 0·94 I 0.06) 4 sample aligned with the SPS pressure direction with a ball-milling time of 1 h, which demonstrates a 35 % enhancement over the pristine sample. This work provides an insightful guide to elevate the thermoelectric properties of layered IVVI 2 Te 4 -based compounds. [ABSTRACT FROM AUTHOR]

In this study, (BiSb) 2 Te 3 thin films were deposited onto glass substrates at a temperature of 300 °C, utilizing radio frequency (RF) sputtering across a range of growth conditions. The primary focus of this investigation was to analyzse the effects of varying RF power, chamber gas pressure, and annealing temperature on the thermoelectric properties of the films, deposited by an exclusively-made single target. Notably, it was observed that increasing the annealing temperature significantly boosted both the deposition rate and grain size. Through carefully optimizsing growth conditions and subsequent annealing procedures, it was discerned that thin films cultivated at higher RF power levels exhibited markedly improved electrical conductivity, attributed to a discernible rise in carrier concentration. Furthermore, films generated under the RF power of 37.5 W showed a noteworthy augmentation in the Seebeck coefficient, recording approximately 147 μV/K. This enhancement in Seebeck coefficient correlated with the attainment of the highest power factor, reaching an impressive 220.57 μW/mK2. [ABSTRACT FROM AUTHOR]

Bi 2 Te 3 -based crystal ingots produced by zone melting (ZM) are the most widely used materials to manufacture commercial thermoelectric (TE) devices. However, the poor mechanical properties of such crystalline materials limit the production of small-scale devices. While processability can be improved by powder metallurgy (PM), it also leads to the deterioration of the TE properties due to the donor-like effect of the introduced defects and grain boundaries. Thus, additional efforts towards re-optimizing doping are required. Here, we report a PM method to improve the mechanical properties of Bi 2 Te 3 -based TE materials through the crushing and hot pressing of Bi 2 Te 3 ingots obtained by ZM. Besides, we demonstrate the TE properties of n-type Bi 2 Te 2.7 Se 0.3 (BTS) to be remarkably improved by Cu doping, which enables optimization of the carrier concentration and enhances phonon scattering at heterointerphases thus increasing the Seebeck coefficient and reducing thermal conductivity. Overall, optimized materials reach dimensionless TE figures of merit (ZT) up to 1.16 at 408 K, i.e. 45% higher than that of state-of-the-art BTS, and an average ZT value of 1.08 in the temperature range of 300–473 K. [ABSTRACT FROM AUTHOR]

Nanostructured Ni-substituted Co1−xNixSb3 (0 ≤ x ≤ 0.08) samples were synthesized using a hydrothermal method. X-ray diffraction analysis confirmed the phase purity of the samples, and a secondary phase was observed in samples with higher Ni substitution ratios (x ≥ 0.06). SEM and TEM images reveal the spherical morphology of the samples with monodispersed particles. Different modes of optic phonon vibrations were observed in Raman spectra, and the intensity of the peaks increased with Ni content and slightly decreased in samples with x values ≥0.06. The electrical resistivity of the samples decreased with Ni content up to an x value of 0.06 and slightly increased in Co0.92Ni0.08Sb3 due to secondary phase formation. The positive Seebeck coefficient values of pure CoSb3 confirm that holes were the majority carriers, whereas the negative Seebeck coefficients of Co1−xNixSb3 samples reveal that Ni substitution enhanced electron concentration in the sample. Co0.96Ni0.04Sb3 exhibited a higher power factor compared with other samples due to its low resistivity. Ni substitution in CoSb3 effectively reduced lattice thermal conductivity (κL) as Co0.96Ni0.04Sb3 showed a lower κL of 2.0 W m−1 K−1 than that of the pure sample due to nanostructuring and the rattling effect of Ni. As a result, a figure of merit of 1.72 was achieved at 553 K for the Co0.96Ni0.04Sb3 sample. [ABSTRACT FROM AUTHOR]

Lead‐free double perovskites are unique materials for transport and optoelectronic applications that use clean resources to generate energy. Using first‐principle computations, this study thoroughly investigates the structural, thermoelectric, and optical attributes of A2TlAgF6 (A = Rb, Cs). Tolerance factor and formation energy estimates are used to verify that these materials exist in the cubic phase. Elastic constants with high melting temperature values are ductile when evaluated for mechanical stability using the Born stability criterion. The optical absorption band is adjusted from 2 to 4 eV via band gaps of 1.88 and 1.99 eV, as indicated by band structures. Analysis of optical properties reveals perfect absorption in the visible spectrum, whole polarization, and low optical loss. Furthermore, thermoelectric properties are assessed at 300, 500, and 700 K in the range of −0.5 to 3 eV for chemical potential (μ). The materials exhibit significant improvements in the Figure of Merit scale due to their elevated electrical conductivity, Seebeck coefficient, and extremely low thermal conductivity values. [ABSTRACT FROM AUTHOR]

High entropy thermoelectric oxides offer a route towards highly efficient thermoelectric energy conversion as the materials frustrate parasitic phonon transport. Here, entropy-stabilised perovskite oxide thermoelectrics (Ca 0.33 Sr 0.33 Ba 0.33)(Ti 0.5−x Zr 0.5−x Nb x)O 3 (x = 0, 0.1, 0.2, 0.33) were prepared via solid-state reaction with sintering at 1673 K under a reducing atmosphere. The products contained two high entropy perovskite phases with homogeneous elemental distributions at the nanoscale. Through optimising the Nb content, the Seebeck coefficient was increased, yielding an enhanced power factor of 39.5 μW m−1 K−2 at 873 K. High resolution transmission electron microscopy revealed the presence of a large number of defects of different dimensionality, which enhanced phonon scattering. A glass-like, ultra-low thermal conductivity of 1.6 – 1.9 W m−1 K−1 was achieved from room temperature to 873 K, amongst the lowest reported values for perovskite oxides. This work highlights the design of high entropy oxide perovskites based on non-toxic components having both high Seebeck coefficients and ultra-low thermal conductivity. [ABSTRACT FROM AUTHOR]

The development of new sulfide and selenide-based thermoelectric (TE) materials is critical for the mass production of TE devices due to the higher earth abundance of S/Se than Te. In this work, we have prepared single crystals of Ag-substituted BaCu2−xAgxSe2 (x = 0 – 0.8) by direct fusion of elements at high temperatures. As characterized by single crystal X-ray diffraction (SCXRD) studies, each of the structures (space group: Pnma) contains two transition metal sites (M1 and M2), and the Ag atoms are disordered with Cu atoms at both sites with a slight preference for the M2 site. Phase pure polycrystalline BaCu2−xAgxSe2 (x = 0 – 1.0) samples have also been synthesized, which are semiconductors as confirmed by optical absorption and resistivity studies. All these samples show positive values of the Seebeck coefficient, suggesting the p-type electrical conduction. Our thermal conductivity (ktot) studies demonstrate a remarkable drop in ktot values on increasing the Ag-substitution in the BaCu2−xAgxSe2 phases with the lowest ktot value of 0.33 W m−1 K−1 (673 K) for the x = 1.0 sample. Our studies show the potential of the BaCuAgSe2 for TE applications with higher zT values if the hole concentration of the phase can be fully optimized. [ABSTRACT FROM AUTHOR]

Ultra‐broadband photodetectors based on semimetal crystals have recently become popular because of their gapless band structures. In particular, semimetal crystals have large carrier mobility or high Seebeck coefficient; this almost eliminates the possibility of using semimetal crystals as photodetectors. In addition, a larger temperature gradient can cause photocurrent generation based on the photothermoelectric effect. Surprisingly, the TaTe2 crystal has a huge absorption coefficient (≈104 cm−1), a minimal specific heat (≈0.172 J g−1 K−1), and a low thermal conductivity (0.3 W m−1 K−1), which is beneficial for generating a high photothermal conversion efficiency of 30.2%, despite its small Seebeck coefficient, and achieving a large temperature gradient occurs for the heat generated by external illumination. Herein, the possibility of photoresponse based on the TaTe2 detector is explored, which has a low carrier mobility (≈10 cm2 V−1 s−1) and a small Seebeck coefficient (≈7.1 µV K−1). The self‐powered TaTe2 photodetector can also provide a competitive photoresponse range from 355 to 2715 nm and exhibit a maximum responsivity of 1.1 mA W−1 with a detectivity of 4.7 × 108 Jones at 455 nm. This study provides a new design scheme and operating mechanism for semimetal photodetectors and enriches semimetal crystal photodetectors. [ABSTRACT FROM AUTHOR]

A comprehensive investigation was conducted on the relationships between molecular structure, morphology and thermoelectric properties of HCl-doped polyaniline (PANi) nanorods subjected to 10MeV electron beam irradiation. Morphological and structural characterization revealed that the crystallinity of irradiated PANi nanorods remained almost unchanged, and minimal oxygen content was detected. This resulted in minimal alterations to the thermo-stability. In addition, the thermoelectric properties of PANi were enhanced. A maximum conductivity of 22.85S/cm was obtained at 50kGy, which was 1.46 times that of pristine PANi. Interestingly, the Seebeck coefficient reached a maximum of −3.56μV/K at 100kGy, indicating n-type organic semiconductor properties. However, a peak power factor of 0.024μWm−1 K−2 was achieved with 60kGy irradiation, which was slightly enhanced compared to 0.018μWm−1K−2 for pristine PANi. These results demonstrate that PANi exhibits good irradiation resistance after irradiated with a dose of 100kGy. Thus, PANi could be used in high-β ray (electron) environments, such as radioisotope thermoelectric generators (RTGs). [ABSTRACT FROM AUTHOR]

Thermoelectric materials are of tremendous interest due to their capacity to convert waste heat into useful electrical energy. Bismuthene nanosheets (BiNS) have recently emerged as a promising material for thermoelectric applications because of their unique two‐dimensional structure and low thermal conductivity. However, the development of efficient and scalable methods for preparing BiNS‐based thermoelectric composites with improved performance remains a challenge. In this study, we reported a novel approach to preparing a thin film BiNS‐based thermoelectric composite with UV‐curing 3D printing technology. The composite was prepared using BiNS as the filler and a UV‐sensitive resin as the matrix, which contained 5 vol% graphene as the third phase to enhance the thermoelectric performance of the composite. The results showed that the prepared composite exhibited stable thermoelectric performance, with a maximum power factor of 311.79 ± 13.90 μW/mK2 when the volume fraction of BiNS reached 95 vol%. The electrical conductivity of the composite improved significantly as the volume fraction of BiNS increased from 75 to 95 vol%. The Seebeck coefficient remained essentially unchanged in the range of 70.1–70.7 μV/K. These findings demonstrate the potential of BiNS‐based thermoelectric composites prepared by UV‐curing 3D printing technology for practical applications in energy harvesting and cooling devices. Highlights: A simple, efficient and scalable method for BiNS thermoelectric composites.UV‐curing 3D printing technology was used for fabrication.The BiNS composite exhibited stable thermoelectric performance.The electrical conductivity of the composite improved significantly.This BiNS composite showed great potential in thermoelectric application. [ABSTRACT FROM AUTHOR]

Exploring N‐type High‐entropy materials with both high thermoelectric and mechanical properties is highly desirable for all‐high‐entropy thermoelectric generators (TEGs) since the thermoelectric and mechanical properties of N‐type one are largely behind its P‐type counterparts. Herein, a new rock‐salt structure N‐type high entropy thermoelectric AgBiPbSe2S is introduced with a bandgap of ≈0.43 eV. The atomic radii difference of each component results in a large lattice distortion of 0.246, leading to a low thermal conductivity of 0.36 W m−1 K−1 at 823 K. The figure of merit (ZT) reaches 0.6 for AgBiPbSe2S at 823 K. Moreover, Ag2Se precipitates are included in AgBiPbSe2S to filter low energy carriers for high Seebeck coefficients and to scatter phonons with nanoscale wavelength for ultralow lattice thermal conductivities. Consequently, a peak ZT of ≈1.18 at 823 K and an average ZT of 0.60 at 400–823 K are obtained for Ag1.02BiPbSe2S. More importantly, high mechanical properties are also obtained in Ag1.02BiPbSe2S, of which the Vickers hardness and flexural strength are ≈209 Hv and 32 MPa, respectively, originating from the enhanced lattice friction by chemical short‐range disorder (i.e., high entropy effect) and dispersion strengthening caused by Ag2Se nanoprecipitates. [ABSTRACT FROM AUTHOR]

The Seebeck effect in graphene with uniform Kekulé lattice distortion has been studied using the tight-binding model combined with the nonequilibrium Green's function method. The numerical results of this work show that the Seebeck coefficient of the O-shaped Kekulé graphene can be enhanced by modulating the gate voltage. At room temperature (T ≈ 300 K), the Seebeck coefficient for the armchair nanoribbon is S c ≈ 1370 μV/K and for the zigzag nanoribbon is S c ≈ 1260 μV/K. At low temperature (T ≈ 128 K), the Seebeck coefficient for the armchair nanoribbon is S c ≈ 2500 μV/K. In addition, the nano-structuration of the O-shaped Kekulé graphene layer induces an anisotropic behavior in the Seebeck effect. Our work provides an idea for the fabrication of efficient and controllable thermoelectric effect devices. [ABSTRACT FROM AUTHOR]

The conversion of heat into electricity using the thermoelectric effect is a crucial issue to tackle the ever-increasing global energy consumption. Cu 2 Se is one of the high-performance thermoelectric materials due to its liquid-like atomic structure, which minimizes the phonon-derived thermal conductivity. Nevertheless, the unambiguous atomic structure of the low-temperature phase, α -Cu 2 Se, remains controversial. By employing a combination of theoretical approaches including an evolutionary algorithm for structural searching, density functional theory, and lattice dynamics, the α -Cu 2 Se phase is proposed to crystalize in the dynamically stable triclinic Cu 2 Se structure (s.g. P1) which can be regarded as a monoclinic polymorph (s.g. P2 1 /c †) through slight distortion. The corresponding heat capacity (C V) and Debye temperature (Θ D) are 0.37 J/g K and 276 K, respectively, indicating low thermal conductivity in the material. The semiconducting P1 phase possesses an indirect gap of 1.0 eV. Additionally, based on the Boltzmann transportation theory, fundamental thermoelectric parameters around the transition temperature (300–500 K) are investigated. Beyond the semiconducting phase, a novel metallic phase identified as the triclinic P 1 ̄ phase is also discovered, exhibiting a two-dimensional (2D) crystal geometry. [ABSTRACT FROM AUTHOR]

Combining DFT-based calculations with Boltzman transport formalism, thermoelectric transport properties of semiconducting two-dimensional SiC-CrS2 and SiC-CrSe2 van der Waal heterostructures are investigated in unstrained and strained conditions. We computed electronic, optical and thermoelectric properties of these heterostructures. We find that these heterostructures are direct band semiconductors having type-II band alignment in unstrained conditions. The transition from the direct to the indirect band is observed in SiC-CrSe2 with compressional strain. Switching from type-II to type-I band alignment is also observed under strained conditions in SiC-CrS2. For thermoelectric properties, we have calculated the Seebeck coefficient, electrical conductivity per relaxation time and power factor at 300 K. Analysis of the power factor revealed a preference for n-type doping under zero strain conditions, whereas changes in PF values induced by strain underscored the potential for tuning the thermoelectric performance of these heterostructures. [ABSTRACT FROM AUTHOR]

Cu2Se‐based binary compounds have recently fetched the attention of researchers due to their remarkable electrical and extremely low thermal properties. In addition, Cu2Se‐based quaternary chalcogenides are expected to present exceptional thermoelectric performance. Cu2Se1−x−ySxTey‐like compounds are synthesized via microwave‐assisted hydrothermal method and their respective thermal and electrical transport properties are studied in this research work. The phase purity and homogeneity are examined by X‐ray diffraction and energy‐dispersive X‐ray spectrometry analysis. The introduction of S and Te elements into Cu2Se matrix enhances Seebeck coefficient resulting in improved electrical performance illustrating a maximum power factor of 989.4 μWK−2 m−1 at 673 K. Furthermore, S‐ and Te‐co‐doped samples exhibit reduced total thermal conductivity values with lowest value of 0.808 WK−1 m−1 for Cu2Se0.96S0.02Te0.02 sample in comparison to 1.18 WK−1 m−1 for the pristine sample. The simultaneous improvement in electrical and thermal properties results in enhanced figure of merit of 0.82 for Cu2Se0.96S0.02Te0.02 sample at 673 K. [ABSTRACT FROM AUTHOR]

The Ca0.6−xSr0.4HoxMnO3−δ (x = 0.05, 0.10, and 0.15) manganites with an orthorhombic crystal structure (space group Pbnm) have been produced via citrate–nitrate route in air. The electron donor holmium (Ho3+) and oxygen nonstoichiometry strongly affect the electrical conductivity (σ), Seebeck coefficient (S), thermal conductivity (κ), and thermal expansion. The increase in the absolute values of S with temperature and the decline of σ above 500 K are explained by the decrease in the concentration of Mn3+ ions due to their disproportionation into Mn2+ and Mn4+ ions. The equilibrium constant of disproportionation, the concentration and mobility of charge carriers depend on temperature and can be derived from the data for S(T) and σ(T). The formation of Mn3+ ions as a result of partial removal of oxygen from the manganites has a strong influence on their properties above 1000 K. Temperature-activated character of mobility and the values of S are consistent with the adiabatic small polaron transport mechanism in Ca0.6−xSr0.4HoxMnO3−δ. [ABSTRACT FROM AUTHOR]

CrSi2 thin films with different thicknesses obtained on the Si(111) surface by magnetron sputtering method have been investigated using complex of electron spectroscopy and microscopy methods. The thin films' composition, surface morphology, and cross-section, as well as the resistivity's, Seebeck coefficient's, and power factor's temperature dependences have been studied for the first time. It has been established that, starting from a thickness of ~ 400 Å (deposition time ~ 60 sec), the SiO2/Si(111) surface is completely covered with an amorphous CrSi2 film. After heating the CrSi2/SiO2/Si(111) system at T ≈ 750 K, a homogeneous polycrystalline CrSi2/SiO2/Si(111) film is formed. It is shown that the resistivity ρ, the Seebeck coefficient S, and the power factor P of a CrSi2/SiO2/Si(111) film of different thicknesses (80 and 180 nm) change nonlinearly with increasing temperature. Their values for CrSi2 films of different thicknesses differ slightly from each other. [ABSTRACT FROM AUTHOR]

Thermoelectric materials have been widely recognized as a simple approach to harness green energy by converting thermal gradients into electrical energy. However, the intricate interplay between electrical conductivity, Seebeck coefficient, and thermal conductivity in thermoelectric materials presents a challenge to improving their efficiency. Traditional experimental methods and calculation methods have troublesome steps and long cycles for predicting new thermoelectric materials. In this work we present materials informatics-based approach, where statistical and machine learning models like correlation matrix, multiple linear regression, principal component analysis and artificial neural network were employed to find the relationship between features and thermoelectric performance. Furthermore, artificial neural network was used to analyze the roles of several compositional and microstructural features along with temperature on electrical conductivity, thermal conductivity, Seebeck coefficient and thermoelectric figure of merit (ZT) for PANI and quasi 0D carbon-based composites. [ABSTRACT FROM AUTHOR]

Double perovskite semiconductors have got extensive research interest for renewable energy applications because of their excellent optoelectronic and thermoelectric properties together with significant structural and chemical stability. However, most of the efficient perovskites are lead based and there is still a big issue of toxicity with these materials. In present study, we have investigated the two non toxic double perovskite X2YIO6 (X = K, Rb) materials for renewable energy applications via first principles calculations. The negative formation and Gibbs free energies confirm the thermodynamic stability while the real frequencies of phonons establish the dynamical stability of these double perovskites. The electronic, optical and thermoelectric properties were calculated via Tran and Blaha modified Becke Johnson potential. The band structure calculations show the direct band gap of 0.98 and 0.75 eV for K2YIO6 and R2YIO6, respectively. On the basis of calculated optical parameters like dielectric function, absorption coefficient and reflectivity, the X2YIO6 compounds could show better solar cells and other optoelectronic applications. The positive values of the Seebeck coefficient categorize both of these double perovskites as p-type semiconductors. Their high values of power factor of the order 10–2 Wm−1 K−2 and figure of merit of the order 0.7 at 1000 K, manifest high power conversion efficiency of these materials at elevated temperatures. [ABSTRACT FROM AUTHOR]

Earth-adequate quaternary chalcogenides like Cu2NiSnS4 with more complex crystal structures can become non-toxic and cost-effective thermoelectric (TE) materials. TE materials, by employing the energy filtering effect through appropriate energy bandgap, have enhanced their TE efficiency. The composition of CuO in Cu2NiSnS4 matrix has enhanced the Seebeck coefficient (S) and declined the thermal conductivity (κ) simultaneously, due to the decrement of carrier concentration (n), by increasing the wt% of CuO in the composites. The highest power factor of 270.88 μW m−1 K−2 at 573 K is recorded for 30 wt% composites. The 30 wt% composite material thermal conductivity exhibited a low value of 0.442 W m−1 K−1 through stronger phonon scattering at the interface boundaries formed between the Cu2NiSnS4 matrix and CuO compositions. A maximum zT of 0.35 for the Cu2NiSnS4/30 wt% CuO composite was obtained, 75% larger than that of the Cu2NiSnS4 matrix at 573 K. This strategy of introducing metal oxides into the metal sulphide matrix for obtaining efficient TE performance could be extended to other eco-friendly quaternary chalcogenides. [ABSTRACT FROM AUTHOR]

Despite remarkable advances, high‐performance thermoelectric (TE) materials‐based thermocouples (TCs) lack mechanical robustness and flexibility. Hence, conventional low Seebeck coefficient metals (Ni, Cu, Fe) wire‐junction‐based TCs are used for temperature sensor applications. However, not only the sensitivity of the metal‐based TC sensor is low, but also it is very difficult to fabricate a pixelated sensor using the conventional approach. In this study, high‐performance (SbBi)2(TeSe)3‐based printed flexible TE materials are employed to fabricate two types of shape‐conformable TC‐based temperature sensor arrays with 25 pixels (TSA I and TSA II). Bi0.5Sb1.5Te3‐based p‐type (p‐BST) printed TE film and copper are used to fabricate TSA I, and the p‐type film together with the Bi2Te2.7Se0.3‐based n‐type (n‐BT) film is used to fabricate TSA II. A high average sensitivity (Sexp) value of ≈124 µV °C−1 for TSA I and ≈319 µV °C−1 for TSA II is attained with high linearity. [ABSTRACT FROM AUTHOR]

In the field of wearable thermoelectric generators, graphene-based materials have attracted attention as suitable candidates due to their low material costs and tunable electronic properties. However, their high thermal conductivity poses significant challenges. Low thermal conductivity due to porous structure of the laser-induced graphene, combined with its affordability and scalability, positions it as a promising candidate for thermoelectric applications. In this study, thermoelectric properties of the laser-induced graphene (LIG) on polyimide and their dependence on structural modifications of LIG were investigated. Furthermore, it was shown that increasing the laser scribing power on polyimide results in larger graphene flakes and a higher degree of graphitization. Electrical conductivity measurements indicated an increase with increasing laser power, due to a higher degree of graphitization, which enhances charge carrier mobility. Our findings reveal that LIG exhibits p-type semiconducting behavior, characterized by a positive Seebeck coefficient. It was shown that increasing laser power increased the Seebeck coefficient and electrical conductivity simultaneously, which is attributed to a charge carrier energy filtering effect arising from structures occurred on the graphene flakes. Moreover, the porous structure of LIG contributes to its relatively low thermal conductivity, ranging between 0.6 W/m·K and 0.85 W/m·K, which enhances the thermoelectric performance of LIG. It has been observed that with increasing laser power, the figure of merit for laser-induced graphene can be enhanced by nearly 10 times, which holds promising applications for laser-induced graphene due to the tunability of its thermoelectric performance by changing laser parameters. [ABSTRACT FROM AUTHOR]

To investigate the possibility of p-type doping of α-SrSi2, a promising as an eco-friendly thermoelectric material, the energy changes of substitutions of the Si site of α-SrSi2 by group 13 elements were evaluated using first-principles calculations. It is found that Ga doping was the most energetically favorable dopant while In is the most unfavorable. We examined the synthesis of Ga- and In-doped α-SrSi2 using the vertical Bridgeman method and investigated their thermoelectric properties. The Ga atoms were doped to α-SrSi2 successfully up to 1.0 at. %, while In atoms could not be doped as suggested by calculations. For experimental prepared Ga-doped samples, the carrier density was observed to increase with Ga doping, from 3.58 × 1019 cm−3 for undoped α-SrSi2 to 4.49 × 1020 cm−3 for a 1.0 at. % Ga-doped sample at 300 K. The temperature dependence of carrier concentrations was observed to change from negative to positive with increasing Ga content. In addition, the temperature dependence of the Seebeck coefficient was also observed to change from negative to positive with increasing Ga content. The results indicate that α-SrSi2 undergoes a semiconductor–metal transition with Ga doping. The power factor for the undoped sample was quite high, at 2.5 mW/mK2, while the sample with 0.3 at. % Ga had a value of 1.1 mW/mK2 at room temperature. [ABSTRACT FROM AUTHOR]

Bi 1.6 Pb 0.4 Sr 2 Co 2 O 8 samples have been textured by the Laser Floating Zone (LFZ) process using Nd:YAG, and CO 2 laser radiation. Using different wavelengths resulted in significant structural and microstructural modifications. Powder XRD patterns showed that the thermoelectric phase is the major one in both cases. Microstructural studies revealed that all samples presented the same phases but with much lower content of secondary ones in those processed with the CO 2 laser. Electrical resistivity showed different behavior for the two types of samples, being in general, lower for the CO 2 grown rods. Seebeck coefficient is lower for the CO 2 grown samples up to 300 °C, and higher in the high-temperature range, reaching 240 μV/K at 650 °C, which is one of the highest values obtained so far in these compounds. Moreover, thermal conductivity at 600 °C for these samples (0.93 W/K m) is among the lowest reported in the literature. As a consequence, ZT values at 600 °C reached 0.42 in CO 2 textured materials, about two times higher than the obtained in Nd:YAG ones. This value is among the highest reported so far in the literature, and is comparable to the performance attained for the same composition containing nanoparticles addition. All these properties, combined with the fact that the processed materials can be directly integrated into thermoelectric modules, render them highly attractive for industrial production. [ABSTRACT FROM AUTHOR]

The structural, optoelectronics, and transport properties of TlTaO3 compounds were determined utilizing the full potential augmented plane wave approach using first‐principle method. We have considered the generalized gradient approximation for structural optimization and modified Becke–Johnson for electronic properties. The electronic properties reveal that the studied TlTaO3 possesses direct bandgap of magnitude 1.52 eV. Between 0 and 12 eV, optical spectra calculations are made, taking into account the real and imaginary parts of the dielectric function, refractive index, and loss function. The transport properties are estimated considering Boltzmann transport theory. The Seebeck coefficient, electrical conductivity, thermal conductivity, and power factor are all assessed using the Boltzmann transport theory. The optimized thermoelectric response of the examined TlTaO3 is produced by the improved carrier mobility, which also improves the thermoelectric efficiency of the TlTaO3. The obtained results will act as a theoretical road map for upcoming experimental and commercial TlTaO3 applications. [ABSTRACT FROM AUTHOR]

Thermoelectric gas sensor (THGS) devices with catalysts and Si0.8Ge0.2 thin films of different boron doping levels of 1018, 1019, and 1020 cm−3 were fabricated, and their transport properties are investigated. SiGe films were deposited on Si3N4/SiO2 multilayers on Si substrates using low-pressure chemical vapor deposition (LPCVD) and thermally annealed at 1050 °C. The Seebeck coefficients of the SiGe films were increased after thermal annealing, ranging from 191 to 275 μV/K at temperatures of 74 to 468 °C in air, and reaching the highest power factor of 6.78 × 10−4 W/mK2 at 468 °C. The thermal conductivity of the SiGe films varied from 2.4 to 3.0 W/mK at 25 °C. The THGS detection performance was tested for the H2 gas in air from 0.01 to 1.0%, and compared to the thermoelectric properties of the SiGe films. The high-temperature annealing treatment process was successful in enhancing the thermoelectric performance of both the SiGe films and sensor devices, achieving the best THGS performance with the sensor device fabricated from the annealed SiGe film with 1018 cm−3 boron-doped Si0.8Ge0.2. [ABSTRACT FROM AUTHOR]

Although orthorhombic GeSe is predicted to have an ultrahigh figure of merit, ZT ≈ 2.5, up to now, the highest experimental value is ≈0.2 due to the low carrier concentration (nH ≈ 1018 cm−3). Improving symmetry is an effective approach for enhancing the ZT of GeSe‐based materials. With Te‐alloying, Ge4Se3Te displays the two‐dimensional hexagonal structure and high nH ≈ 1.23 × 1021 cm−3. Interestingly, Ge4Se3Te transformed from the hexagonal into the rhombohedral phase with only ≈2% I–V–VI2‐alloying (I = Li, Na, K, Cu, Ag; V = Sb, Bi; VI = Se, Te). According to the calculated results of Ge0.82Ag0.09Bi0.09Se0.614Te0.386 single‐crystal grown via AgBiTe2‐alloying, it exhibits a higher valley degeneracy than the hexagonal Ge4Se3Te. For instance, AgBiTe2‐alloying induces a strong band convergence and band inversion effect, resulting in a significantly enhanced Seebeck coefficient and power factor with a similar nH from 17 µV K−1 and 0.63 µW cm−1 K−2 for pristine Ge4Se3Te to 124 µV K−1 and 5.97 µW cm−1 K−2 for 12%AgBiTe2‐alloyed sample, respectively. Moreover, the sharply reduced phonon velocity, nano‐domain wall structure, and strong anharmonicity lead to low lattice thermal conductivity. As a result, a record‐high average ZT ≈0.95 over 323–773 K with an excellent ZT ≈ 1.30 is achieved at 723 K. [ABSTRACT FROM AUTHOR]

The mechanical, electronic, magneto-optic and thermoelectric properties of CeBiPt compound have been calculated based on density functional theory (DFT) calculations. This compound has ground state point in the ferromagnetic phase with elastic stability by large bulk modulus of 88.565 GPa. Poisson's coefficient of 0.257 represents the ionic bonds between atoms, while the anisotropy coefficient indicates the elastic isotropic nature of this compound. Also, phonon dispersion emphasizes to the dynamic stability of this compound. By the mBJ approximation, this case exhibits ferromagnetic behavior with a magnetic moment of 0.98 μ B . Based on the magnetic behavior of this crystal, the Kerr effect angles ( θ k ) are 3.6∘ at 3 eV and − 3. 5 ∘ at 5.4 eV, respectively, therefore, the rotation angle of the ellipse light polarization ( γ k ) in the edge of ultraviolet region shows a large polarization of light in the visible region. The negative Seebeck coefficient of CeBiPt compound at low temperature refers to the hole transfer, also the magnitude of the power factor at higher temperatures indicates this compound is suitable for use in power generator applications. [ABSTRACT FROM AUTHOR]

In this work, we used solvothermal technique to synthesize thermoelectrically viable Zn–Mn co-doped SnTe materials. However, the thermoelectric (TE) performance of pure SnTe is subpar due to the significant energy gap between its valence bands, inherent Sn-vacancies, and high electrical thermal conductivity. Band structure engineering and carrier concentration optimization of SnTe following Zn–Mn co-doping have the potential to enhance the Seebeck coefficient. In turn, a boost in the Seebeck coefficient significantly improved the power factor in Sn0.89Mn0.09Zn0.02Te by about five times as compared to pure SnTe at 473 K. The minimum lattice thermal conductivity (κ L) in Sn0.89Mn0.09Zn0.02Te is 0.54 W m−1K−1 at 473 K, which is almost half that of pure SnTe. The lower lattice thermal conductivity of co-doped samples may be a result of (i) a decrease in phonon group velocity by chemical bond softening and (ii) phonon scattering caused by nanostructuring, point defects, and grain boundaries. Consequently, maximum zT = 0.11 has been achieved in Sn0.89Mn0.09Zn0.02Te at 473 K, which is about five times that of pristine SnTe. Material quality factor (B) of Sn0.89Mn0.09Zn0.02Te is almost triple that of pristine SnTe at 473 K, which implies that Zn–Mn co-doped SnTe is more suited to construct a TE device. An increase in electric transport properties (weighted mobility and electronic quality factor) and a decrease in κ L after Zn–Mn co-doping contribute to the enhancement of B. The findings of this investigation suggest that the addition of Zn and Mn to SnTe can improve its TE performance. [ABSTRACT FROM AUTHOR]

Making products that are affordable, environmentally friendly, and energy‐efficient is the main objective of modern production. The objective of this research is to discover compounds that meet these parameters. The full‐potential, linearized augmented plane wave program (FP LAPW) offered by Wien2K was used to examine the structural, optical, electrical, and transport aspects of SrCaGe and SrCaSn Half‐Heusler (HHs) compounds. Generalized gradient approximation (GGA) was considered for the structural optimization and computation of elastic properties signifies inherent ductility and mechanical stability of the examined SrCaGe and SrCaSn compounds. Additionally, both materials were found to possess a direct bandgap and exhibit semiconducting behavior. The bandgap magnitudes obtained utilizing the modified Becke‐Johnson (mBJ) approximation are 0.78 and 0.52 eV for SrCaGe and SrCaSn, respectively. According to their optical characteristics, SrCaGe and SrCaSn show potential for application in optoelectronic components. Furthermore, the transport properties are evaluated by BoltzTrap program, revealing that both SrCaGe and SrCaSn exhibit figures of merit (ZT) values nearly equal to one at room temperature. This suggests their potential use in creating thermoelectric devices with highly efficient performance. The simulation study demonstrates the promising attributes of SrCaGe and SrCaSn HHs materials, positioning them as viable candidates for various applications, aligned with the goals of sustainable and efficient manufacturing. [ABSTRACT FROM AUTHOR]

In the face of ever‐evolving energy and environmental challenges, tin selenide (SnSe) has garnered significant attention due to its outstanding thermoelectric performance. The article focuses on the research of easily accessible and highly practical polycrystalline SnSe thermoelectric materials, providing an overview of their crystal structure, band structure, and electrical transport performance. Compared with previous studies, this research classifies elements based on their own properties, mainly dividing them into alkali metals, transition metals, main group metals, halogens, and rare earth (Re) elements. The study systematically summarizes the experimental results of doping SnSe with these elements and analyzes the mechanisms by which different elements enhance the electrical transport performance and thermoelectric figure of merit of polycrystalline SnSe. The enhanced mechanism is mainly achieved by increasing the conductivity and Seebeck coefficient. Finally, a systematic analysis is conducted to identify the factors that improve electrical transport performance, and strategies for enhancing the electrical transport and thermoelectric properties of polycrystalline SnSe through precise doping techniques are discussed, with a prospect for their application in the future. [ABSTRACT FROM AUTHOR]

This study investigated the effects of CuAl2O4 (CuAl) on four types of spinel ferrites: CoFe2O4 (CoF), NiFe2O4 (NiF), MgFe2O4 (MgF), and ZnFe2O4 (ZnF) with regards to their electrical characteristics and microscopic magnetic behavior. According to the Seebeck coefficient (φ), the nanocomposites have a mixture of positive and negative charge carriers, except for CoF/CuAl, which has a positive charge carrier only. Depending on the temperature, the DC conductivity of all MF/CuAl nanocomposites has a conductor and semiconductor behavior. The dielectric properties were studied at different frequencies (100–10^8 Hz) and temperatures (300–673 K). The results demonstrated how temperature and frequency affect AC operating mechanisms. The high values of dielectric loss for all nanocomposites confirm their applicability in high-frequency microwave devices. The impedance study revealed that the equivalent circuit for all MF/CuAl nanocomposites is a mixture of R, L, and C. Temperature-magnetization graphs were obtained for all nanocomposites, indicating ferrimagnetic behavior except ZnF/CuAl. The magnetic transition temperature (TCm), the Curie–Weiss constant (θCW), and the effective magnetic moments (μeff) for all nanocomposites were determined. The MF/CuAl samples were analyzed using ESR spectroscopy at room temperature. The spectra were distorted but remained distinct, potent, and sweeping. The g-factor values deviate from the free electron, which suggests that the Fe3+–O–Fe3+ superexchange interaction has changed. In addition, the interaction effect between MF and CuAl is discussed. [ABSTRACT FROM AUTHOR]

We study thermoelectric and transport properties of armchair nanoribbon doped with impurity atoms in the context of tight binding model hamiltonian. The effect of scattering by dilute charged impurities is discussed in terms of the self-consistent Born approximation. Green's function approach has been implemented to find the behavior of density of states, transport and Seebeck coefficient of armchair nanoribbon within linear response theory. We have found the temperature dependence of electrical and thermal conductivities for different values of impurity concentration and scattering strength of dopant impurity. Also the dependence of Seebeck coefficient and figure of merit on temperature has been investigated in details. A peak appears in the curves of temperature dependence of Seebeck coefficient and figure of merit for various impurity concentrations and scattering potential strengths. Furtheremore we have found electrical conductivity rises with impurity concentration for any temperature and scattering potential strength. [ABSTRACT FROM AUTHOR]

The thermoelectric properties of inhomogeneous BCN alloy nanotubes are investigated using a first-principles approach and the non-equilibrium Green's function method based on virtual crystal approximation. The asymmetric distribution of B, C, and N atoms in these nanotubes causes tilted transmission probabilities around the Fermi level, disrupting electron–hole symmetry under varying temperature gradients. Consequently, the thermal charge currents exhibit fascinating behaviors like negative differential thermal resistance and thermoelectric current switching. Reducing the carbon concentration leads to decreased electrical conductance, electronic thermal conductance and Lorenz number but increased Seebeck coefficient and figure of merit. This emphasizes the significance of carbon concentration in tuning the thermoelectric efficiency of these nanotubes, suggesting a possibility for tailored thermoelectric nanomaterial design. [ABSTRACT FROM AUTHOR]

In this paper, we present the effects of annealing in a vacuum on the structural, electrical, thermoelectric, optical and properties of a glass/ITO (40 nm)/Cu (5 nm)/Ni (10 nm)/ITO (40 nm) multilayer prepared on glass substrates at room temperature using the Radio Frequency (RF) sputtering technique. The effect of annealing in a vacuum is investigated. The structures of the ICNI were analyzed using X-Ray Reflectivity (XRR) and X-Ray Diffraction (XRD). Furthermore, the electrical and optical properties were characterized using the four-point probe measurement method and a UV–Vis-NIR spectrometer, respectively. The influence of the annealing temperature in a vacuum on transmittance, structural integrity, electrical behavior, energy band gap, resistivity, Seebeck coefficient, and figure of merit were investigated. [ABSTRACT FROM AUTHOR]