Thermoelectric Measurements Research Articles

Seebeck Coefficient Modulation of Graphene Grown on Faceted Cu Surfaces

The thermoelectric properties of polycrystalline copper (Cu) surfaces partially covered with graphene grown by Joule‐heating chemical vapor deposition using scanning thermoelectric microscopy are investigated. Atomic‐resolution atomic force microscopy topographic images of graphene grown on Cu(100) surfaces showed a 1D stripe pattern of Moiré superlattices, while thermoelectric voltage images clearly distinguish wrinkle defects caused by thermal mismatch between graphene and Cu substrate. Regions of different signs were found in the thermoelectric voltage image of the graphene island, which are attributed to the faceted surface of the Cu substrate. In addition, faceted surfaces consisting of low‐ and high‐index Cu surfaces are formed on the Cu grain to minimize the surface energy. Due to these structural changes, charge transfer and chemical interactions at the interface between the graphene and Cu facets affect the electronic structure of the graphene, which is understood as the observed Seebeck coefficients with different signs in the thermoelectric microscopy measurements, which are sensitive to the local density of states.

High temperature thermoelectric properties of BaxSr2−xFeCoO6 double perovskites

Abstract In this study, environmentally benign BaxSr2-xFeCoO6 (BSFC) double perovskites are synthesized via solid-state reaction route for high-temperature thermoelectric applications. The crystal structure and morphology of the ceramic samples are analyzed using XRD and SEM, respectively. Rietveld refinement of XRD data confirms a cubic structure with Pm3̅m space-group. High-temperature thermoelectric measurements exhibits that substituting Ba for Sr in Sr2FeCoO6 increases the Seebeck coefficient (S) but at the expense of the electrical conductivity (σ). The highest Seebeck coefficient of 117 μV/K has been observed in Ba0.5Sr1.5FeCoO6 at 910 K. Temperature-dependent electrical conductivity measurements indicates a semiconductor-to-metal like transition in all samples, with BSFC (x = 0.1) achieving the highest conductivity of 4 × 104 S m−1 at ∼623 K. The thermoelectric power factor has been enhanced by over 50% with Ba substitution in Sr2FeCoO6. Electron transport in these double perovskites is found to follow the small polaron hopping conduction mechanism.

Novel approach for in-line process monitoring during ultrasonic metal welding of dissimilar wire/terminal joints based on the thermoelectric effect

AbstractUltrasonic metal welding (USMW) is a manufacturing technique widely employed in the automotive and aerospace industries due to its efficiency in joining similar as well as dissimilar metals. Despite its prevalence, the lack of effective in-line process monitoring methods has resulted in high scrap rates, product recalls due to unrecognized scrap or financial losses due to pseudo-scrap, limiting its application in more sensitive industries. This paper presents a novel thermoelectric effect-based method for in-line process monitoring of USMW processes. This approach utilizes the thermoelectric properties, that manifest at the junctions of dissimilar metals during welding to accurately measure the temperature of the weld zone without the need of additional thermocouples, pyrometers or infrared cameras. An experimental setup was developed to validate the thermoelectric-based temperature measurement methodology. Key to this approach is the detection of thermoelectric voltage developed due to thermo diffusion when dissimilar materials are joined. The experiments showed a strong correlation between the thermoelectric voltage and the mechanical strength of the welds, suggesting that this parameter can effectively predict the quality of the weld. In the trials, a series of welded samples was created under controlled conditions to measure the generated thermoelectric voltage and correlate it with ultimate tensile strength tests. The data were analyzed using Spearman’s correlation coefficients to determine the correlation of the thermoelectric signals and joint strength. Results indicate that the thermoelectric voltage measurements correlate highly with the joint strength, with a Spearman’s correlation coefficient of over 0.94, thereby providing a promising predictive metric for assessing weld quality.

Effect of magnetic entropy in the thermoelectric properties of Fe-doped Fe2VAl full-Heusler alloy

The effect of spin entropy on the transport of heat/charge carriers in the Fe-doped full-Heusler alloy Fe2+xVAl1-x with x = 0–0.1 has been studied through low-temperature magnetic and thermoelectric measurements. Magnetization (M) measurements confirm itinerant-electron weak-ferromagnetic behavior. A systematic increase of the magnetic transition temperature TC (from 40 K to 223 K) and of the saturation magnetization (from 0.13 to 0.41μB/Fe) with increasing Fe doping (from x = 0 to 0.1) is observed. Applying a magnetic field causes significant suppression of the Seebeck coefficient (S) and the entropy term (S/T) with a negative magnetoresistance near TC for all weak-ferromagnetic samples, demonstrating a clear effect of spin fluctuations. Analyzing M(T) and S(T), we rule out sizeable magnon drag contributions. A large spin fluctuations-induced enhancement in the thermoelectric power factor PF of about 18 % is achieved for x = 0.1 near TC when compared to measurements in a magnetic field of 7 T. The actual improvement in PF is even much higher, as the S shows a significant enhancement (about 34 %) compared to the estimated diffusion term of S(T) at TC. The number of point defects also increases with Fe doping, causing a significant reduction of the lattice thermal conductivity. This study demonstrates the role of spin fluctuations in enhancing the thermopower/thermoelectric performance of Fe-doped Fe2VAl and opens a vista for the strategy's applicability for various thermoelectric materials.

Facile synthesis of cerium and vanadium doped nickel oxide nanoparticles for the enhancement of optical, electrical and thermoelectric properties

To investigate the optical, electrical and thermoelectric properties of pristine, cerium and vanadium doped NiO-NPs was synthesized by using sol-gel method. The XRD was used to investigate the FCC cubic crystal structure and crystallite size decreased from 75 to 43 nm. However, SEM micrographs depicted irregular surface morphology changed into small agglomerated grains by vanadium doped NiO-NPs. After that the EDAX analysis was performed to obtain the elemental composition (Ni, O, Ce and V) and also identified the weight percent of each element in all samples. The different functional groups such as Ni-O, OH, C-O, CO2, C=C and V-O was examined by FTIR spectra. The absorbance peak of pristine and doped NiO NPs indicate the blue shift and band gap decreased from 3.52 to 3.30 eV was calculated by UV-VIS analysis. The electrical properties were examined with two probe method and draw the relation between resistivity and conductivity. It was observed that the resistivity decreased (6 × 103 to 2 × 103 ohm-cm) with Ce and V doped NiO-NPs and conductivity increased (2 × 10-5 to 6 × 10-3 S/cm). Further, seebeck coefficient was calculated with the help of thermoelectric analysis and it was observed that seebeck coefficient increased by increasing temperature upto significant level. Overall analyses shows that vanadium doped NiO-NPs are excellent candidate for optical, electrical and thermoelectric measurements. While as prepared cerium and vanadium doped NiO-NPs will be helpful of electrical and thermoelectric devices.

Thermoelectric and electrical transport properties of mixed-conducting multicomponent oxides based on Ba(Zr,Ce)O3-δ

In this work, the chosen physicochemical properties of single-phase multicomponent oxides BaTi1/8Fe1/8Co1/8Y1/8Zr1/8Sn1/8Ce1/8Hf1/8O3-δ and BaTi1/9Fe1/9Co1/9Y1/9Zr1/9Sn1/9Ce1/9Hf1/9Bi1/9O3-δ were studied. The microstructure of the compounds strongly depended on the presence of bismuth in the structure. The electrical transport studies showed a level of electrical conductivity of ∼10-3 - 10-2 S/cm in the temperature range 673 – 1073 K. Electrical conductivity was thermally activated and the dominant conduction mechanism was the hopping of small polarons. Moreover, total electrical conductivity changes in the dry and humidified atmosphere at lower temperatures due to the presence of protonic defects in the structure. Thermoelectric measurements showed a relatively high value of the Seebeck coefficient for studied ceramics. Its values ranged between 50 and 250 μV/K depending on the sample and temperature. The Seebeck coefficient sign was positive, meaning that electron holes and/or oxygen vacancies were predominant charge carriers in oxidising atmospheres. Additionally, the Seebeck coefficient was found to be different in the humidified atmosphere which indicates an influence of protonic defects on thermoelectric transport. The obtained power factor Pf turned out to be low and dependent on the presence of protonic defects in the structure. This indicates, that the efficiency of the MOs-based operating thermoelectric generators can be controlled by changing the partial pressure of water vapor.

Semiconducting Heusler Compounds beyond the Slater-Pauling Rule

Heusler compounds with semiconducting properties represent an important class of functional materials. Usually, research on these systems is guided by simple electron-counting rules, such as the Slater-Pauling principle. Here, we report on the discovery of Heusler-type semiconductors, significantly deviating from the Slater-Pauling rule. We theoretically predict the occurrence of nonmagnetic semiconducting ground states in various highly off-stoichiometric full-Heusler alloys, where self-substitution leads to a band-gap opening. This unexpected trend is confirmed experimentally by thermoelectric transport measurements on a multitude of Fe2−2xV1−xAl1+3x samples with up to 20% substitution of Fe and V atoms. The band-gap opening leads to an exceptionally large Seebeck coefficient in p-type Fe2VAl thermoelectrics, previously limited by bipolar conduction and low-density-of-states effective mass. Consequently, our work presents a paradigm to tune the band gap of Heusler compounds by self-substitution and introduces a hitherto unexplored class of semiconductors with exceptional thermoelectric properties, offering significant potential for advancements in energy science and sustainable-energy technologies. Published by the American Physical Society 2024

Fabrication and thermoelectric properties of multilayer textured Sr-doped Ca3Co4O9/Ag laminar composites

This work presents a comparative analysis of pure and Ag-intercalated Ca3Co4O9 multilayer thermoelectric materials prepared through the hot-uniaxial pressing technique. Samples were prepared by attrition milling and hot-pressed at 900 °C and 55 MPa for 1 h. They were mirror polished, and some of them were stacked with and without intermediate Ag foil and hot-pressed again at 900 °C and 52 MPa for 1 h. Out-of-plane XRD showed that samples are nearly single-phase, and the grains are well oriented with their ab-plane perpendicular to the pressure direction. Microstructural studies confirmed perfect welding in the multilayer samples accompanied by the formation of a very thin layer containing larger grains and notable Ag diffusion close to the Ca3Co4O9/Ag interface. Three-point bending stresses have been increased in Ag-containing samples, while microhardness has been raised in all samples hot-pressed twice. Thermoelectric measurements showed a decrease of thermal gradient along the Ag-containing sample, together with a drastic decrease of electrical resistivity when compared to the Ag-free ones. However, the Ag-layers have promoted a drastic decrease in the Seebeck coefficient, reflected in a notable reduction of the power factor of Ca3Co4O9/Ag multilayer composites. Nevertheless, these results show that it is possible to use these materials to reduce Joule heating and increasing the compatibility with the welding compounds when building thermoelectric modules. Moreover, they open a new research line searching for larger S compounds to be intercalated with Ag foils.

Thermoelectric measurements of nanomaterials by nanodiamond quantum thermometry

In this study, the Seebeck coefficient of a single-walled carbon nanotube (SWCNT) was evaluated using a nitrogen vacancy center in nanodiamonds as a thermometer. A temperature gradient was established across the SWCNT, and the temperatures of the nanodiamonds on the electrodes, along with the electromotive force between these electrodes, were measured. The Seebeck coefficient for a metallic SWCNT was determined to be 14.0 ± 1.1 μV K−1, which is consistent with results reported in previous studies. This methodology offers a promising approach for evaluating the thermoelectric properties of various nanomaterials.

High temperature setup for measurement of Hall coefficient and electrical conductivity of thermoelectric materials.

An experimental setup has been developed for the simultaneous measurement of the Hall coefficient (RH) and electrical conductivity (σ) of thermoelectric (TE) specimens in the temperature range of 300-700K. The van der Pauw geometry is utilized for the RH and σ measurements. The sample holder geometry has been designed for diverse TE specimen dimensions and easy sample mounting. A special feature of the holder geometry is that the same sample can be used for other relevant thermoelectric measurements such as the Seebeck coefficient and thermal diffusivity. This minimizes measurement errors associated with compositional or doping inhomogeneities. In the absence of high temperature standard reference materials for Hall coefficient measurements, silicon samples with different doping concentrations have been used to verify the accuracy of the instrument. Additionally, the electrical conductivity data have been validated by measurements on the same samples in a calibrated setup. Repeat measurements indicate a maximum standard deviation of ±3% and ±0.5% for the RH and σ data in the studied temperature range. Furthermore, comparisons with the calibrated setup indicate deviations within ±3% for the σ data. The suitability of the measurement setup for TE specimens has been demonstrated using measurements on n-type (Mg2Sn) and p-type (Mg3Sb2) specimens with carrier concentrations in the range of 1019-1020cm-3.

(Invited) Electrochemical Tuning of Thermoelectric Performance of Carbon Nanotubes

One-dimensional materials have potential for high performance thermoelectric energy conversion. To experimentally understand how one-dimensional electronic structures can enhance thermoelectric performance, we have investigated the thermoelectric properties of single walled carbon nanotubes (SWCNTs) such as the relationships among electronic structures, the location of Fermi-level, Seebeck coefficients, and Power factor by combining thermoelectric measurements and electrolyte gating techniques. Through the studies, we have revealed unique properties such as violation of thermoelectric trade-off, isotropic Seebeck coefficient, and gigantic power factor [1]. However, in addition to that, it is important to understand how the carrier density also affects the thermal conductivity of the carbon nanotube thin films for correct evaluation of ZT value. Therefore, we have developed a measurement system which can evaluate thermal conductivity by tuning the location of Fermi-level through electrochemical gating techniques. Time-domain thermoreflectance (TDTR) measurement is one of methods which can evaluate the thin film thermal conductivity. In conventional TDTR system, Al is used as metal transducer, but Al is electrochemical reactive, and thus it is very difficult to combine the TDTR measurements with electrochemical techniques. To solve this problem, we developed a TDTR system using Au as a metal transducer [2]. By using Au as a metal transducer, we can evaluate both the electrical and thermal properties at the same time. By using system, we can evaluate thermal properties of thin films during electrolyte gating, and have evaluated how the change of charrier density affects the thermal conductivity of carbon nanotube thin films [3]. By preparing the aligned single-walled carbon nanotube thin film, we evaluated the ZT value in the perpendicular direction to the nanotube axis as a function of carrier density. The ZT value in this direction can be maximized to be 0.1 by tuning the Femi-level around 1st van hove singularity [4].

Synthesis of Zintl Phase Metal Silicide Thermoelectric Materials in Magnesium/Zinc Flux.

Zintl phases have potential applications as thermoelectric materials for power generation and cooling owing to their complex crystal structures and unique electronic properties. We carried out reactions of silicon with barium and strontium in excess Mg/Zn flux to synthesize (Ba/Sr)5+xMg19-xSi12 Zintl phases, investigating the effect of varying Ba/Sr ratio on site mixing and thermoelectric properties. (Ba/Sr)5+xMg19-xSi12 compounds with 0 < x < 3 are charge-balanced Zintl phases which adopt the hexagonal Ho5Ni19P12 structure type (space group P6̅2m). Density of states calculations indicate that these materials are semimetals. Single-crystal X-ray diffraction data and elemental analysis for Ba5Mg19Si12, Ba4.86Sr2.94Mg16.20Si12, Ba3.63Sr4.20Mg16.17Si12, Ba1.93Sr5.99Mg16.08Si12, and Sr7.82Mg16.18Si12 show occupation of barium and strontium cations in Ho sites, while strontium mixes with magnesium on a specific Ni site. Powder XRD data of products show that they are single phase throughout the sample. Thermoelectric measurements indicate that increasing strontium content and mixing on three cation sites decreases thermal conductivity; it is hypothesized that improved overall thermoelectric behavior is likely due to the rattling of the Sr cations in their positions.

Golden ratio of the r+/r- for the structure-selectivity in the thermoelectric BaZn2-xCdxSb2 system

A total of five Zintl phase compounds in the solid-solution BaZn2-xCdxSb2 (0.10(2) ≤ x ≤ 2) system have been successfully synthesized by the molten Pb-flux method. Both powder X-ray and single-crystal X-ray diffraction analyses proved that the title compounds displayed the phase transition between the BaCu2S2-type phase (space group Pnma, Z = 4) and the CaAl2Si2-type phase (space group P3¯m1, Z = 1) depending on the Zn/Cd mixed ratio. Furthermore, this kind of structure selectivity was dictated by the radius ratio criterion between the cationic and the anionic elements (r+/r–): three Zn-rich compounds with the r+/r– > 1 (BaZn1.90(1)Cd0.10Sb2, BaZn1.75(2)Cd0.25Sb2, and BaZn1.62(2)Cd0.38Sb2) preferred to adopt the BaCu2S2-type phase, while two Cd-rich compounds with the r+/r– ≤ 1 (BaZn0.16(2)Cd1.84Sb2 and BaCd2Sb2) preferred to crystallize in the trigonal CaAl2Si2-type phase. A series of TB-LMTO calculations using the two hypothetical models: BaZn1.5Cd0.5Sb2 and BaZn0.5Cd1.5Sb2, proved that a resonance peak in the density of states of BaZn1.5Cd0.5Sb2 implied the enhanced Seebeck coefficient of the three Zn-rich compounds, and the reduction of band gap observed in a band structure of BaZn0.5Cd1.5Sb2 influenced the electrical conductivity of the Cd-rich BaZn0.16(2)Cd1.84Sb2. Temperature-dependent thermoelectric property measurements showed the maximum ZT of 0.54 for the quaternary BaZn1.62(2)Cd0.38Sb2, which should mainly be attributed to the reduced κtot due to the Zn and Cd disordering in the anionic frameworks.

Excess noise and thermoelectric effect in magnetron-sputtered VO2 thin films

This work presents the excess noise and thermoelectric (Seebeck) measurements on polycrystalline vanadium dioxide (VO2) thin films. Noise spectral power density (SPD) of current fluctuations in the semiconducting (SC) phase had a typical flicker noise (f−γ) characteristic with an average slope parameter γ of 1.13. Normalized SPD (Sn) values obtained in the SC-phase indicate that the noise originates in the bulk of the film. On the contrary, in the metallic (M)-phase, γ values were greater than unity, and the observed Sn values indicated that the origin of the noise is most likely from the contacts or surface rather than the bulk. A general decrease was observed in Sn by a factor of 4–5 from the SC- to M-phase. Moreover, Sn in the SC-phase showed no temperature dependence. An interpretation based on the number of charge carrier fluctuations in Hooge's model led to an unrealistically high Hooge parameter and had to be ruled out. We propose that the fluctuations are related to the mobility fluctuations of carriers arising primarily from grain-boundary scattering which explains the observed characteristics well. The Seebeck coefficients (S) obtained under both heating and cooling schedules showed the n-type nature of magnetron-sputtered VO2 films in the SC-phase. Differently, in the M-phase, the S value was positive. The S values obtained from the cooling schedule signified the low percolation threshold of the metal-to-insulator transition already demonstrated for VO2 thin films grown on r-cut sapphire using the Efros–Shklovskii percolation model.

A comprehensive experimental and DFT analysis on thermoelectric properties of Sb, Te co-doped Bi2Se3 polycrystals

As tellurides and selenides of Bismuth are extensively used thermoelectric materials in the low-temperature range with refrigeration application, A concerted effort is put forth to boost the ZT by co-doping the pristine Bi2Se3 with antimony (Sb) on cation end and tellurium (Te) on anion side of the compound. The double sintered solid-state reaction method is employed in the preparation of Bi2Se3 and (Bi1−xSbx)2Se2.7Te0.3 polycrystalline pellets, with x = 0.02, 0.04, and 0.06. The sample exhibits a rhombohedral structure with the space group of R 3¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\overline{3 }$$\\end{document} m. FESEM and EDAX analysis are used to confirm surface morphology and elemental composition of the produced samples. The thermoelectric measurements for the pristine and co-doped samples were conducted by the physical property measurement system as well as a considerable increase in the Seebeck coefficient of − 115 µV/K is observed for 0.02 doping of the Sb which is 4.2 times greater than as for pristine (S = − 28 µV/K). Higher concentration doping (x = 0.04, 0.06) has not reflected any Seebeck coefficient advancement. In contrast, the lowest total thermal conductivity at a low-temperature regime (< 50 K) is observed for x = 0.06 doping concentration which at near room temperature increases beyond the pristine thermal conductivity; whereas, x = 0.02, 0.04 doping concentration shows a decrement in total thermal conductivity at low, at room temperature region the values are almost equivalent to that of pristine. The co-doped samples’ electrical resistivity is substantially less than pristine sample. The highest power factor of 3 × 10–4 µW/mK2 is obtained for the x = 0.02 sample. The highest ZT value for the x = 0.02 sample is almost 28 times more than a pristine sample. We conducted a study where we combined experimental and DFT methods to investigate thermoelectric properties incorporated into pristine and doped with antimony and tellurium on Bi2Se3. We have employed this combination to investigate the partial density of states, Seebeck coefficient, power factor using the Boltzmann transport equation. Theoretical thermoelectric data were derived and compared to experimental observations. Hence, using combined experimental and theoretical investigations helps to predict with higher accuracy of thermoelectric properties of semiconducting materials.

Advancing Heteroanionicity in Zintl Phases: Crystal Structures, Thermoelectric and Magnetic Properties of Two Quaternary Semiconducting Arsenide Oxides, Eu8Zn2As6O and Eu14Zn5As12O.

Two novel quaternary oxyarsenides, Eu8Zn2As6O and Eu14Zn5As12O, were synthesized through metal flux reactions, and their crystal structures were established by single-crystal X-ray diffraction methods. Eu8Zn2As6O crystallizes in the orthorhombic space group Pbca, featuring polyanionic ribbons composed of corner-shared triangular [ZnAs3] units, running along the [100] direction. The structure of Eu14Zn5As12O crystallizes in the monoclinic space group P2/m and its anionic substructure can be described as an infinite "ribbonlike" chain comprised of [ZnAs3] trigonal-planar units, although the structural complexity here is greater and also amplified by disorder on multiple crystallographic positions. In both structures, the O2- anion occupies an octahedral void with six neighboring Eu2+ cations. Formal electron counting, electronic structure calculations, and transport properties reveal the charge-balanced semiconducting nature of these heteroanionic Zintl phases. High-temperature thermoelectric transport properties measurements on Eu14Zn5As12O reveal relatively high resistivity (ρ500K = 8 Ω·cm) and Seebeck coefficient values (S500K = 220 μV K-1), along with a low concentration and mobility of holes as the dominant charge-carriers (n500K = 8.0 × 1017 cm-3, μ500K = 6.4 cm2/V s). Magnetic studies indicate the presence of divalent Eu2+ species in Eu14Zn5As12O and complex magnetic ordering, with two transitions observed at T1 = 21.6 K and T2 = 9 K.

Vortex entropy and superconducting fluctuations in ultrathin underdoped Bi2Sr2CaCu2O8+x superconductor

Vortices in superconductors can help identify emergent phenomena but certain fundamental aspects of vortices, such as their entropy, remain poorly understood. Here, we study the vortex entropy in underdoped Bi2Sr2CaCu2O8+x by measuring both magneto-resistivity and Nernst effect on ultrathin flakes (≤2 unit-cell). We extract the London penetration depth from the magneto-transport measurements on samples with different doping levels. It reveals that the superfluid phase stiffness ρs scales linearly with the superconducting transition temperature Tc, down to the extremely underdoped case. On the same batch of ultrathin flakes, we measure the Nernst effect via on-chip thermometry. Together, we obtain the vortex entropy and find that it decays exponentially with Tc or ρs. We further analyze the Nernst signal above Tc in the framework of Gaussian superconducting fluctuations. The combination of electrical and thermoelectric measurements in the two-dimensional limit provides fresh insight into high temperature superconductivity.

Harnessing Quantum Capacitance in 2D Material/Molecular Layer Junctions for Novel Electronic Device Functionality.

Two-dimensional (2D) materials promise advances in electronic devices beyond Moore's scaling law through extended functionality, such as non-monotonic dependence of device parameters on input parameters. However, the robustness and performance of effects like negative differential resistance (NDR) and anti-ambipolar behavior have been limited in scale and robustness by relying on atomic defects and complex heterojunctions. In this paper, we introduce a novel device concept that utilizes the quantum capacitance of junctions between 2D materials and molecular layers. We realized a variable capacitance 2D molecular junction (vc2Dmj) diode through the scalable integration of graphene and single layers of stearic acid. The vc2Dmj exhibits NDR with a substantial peak-to-valley ratio even at room temperature and an active negative resistance region. The origin of this unique behavior was identified through thermoelectric measurements and ab initio calculations to be a hybridization effect between graphene and the molecular layer. The enhancement of device parameters through morphology optimization highlights the potential of our approach toward new functionalities that advance the landscape of future electronics.

Study of Photovoltaic Double-Skin Façade Windows in Passenger Ships

The ship-mounted photovoltaic (PV) system was an approach to solve the problem of pollution caused by excessive energy consumption during navigation. However, PV systems used on ships faced problems such as small installation areas, which prevented PV power generation from being utilized on a large scale. This article proposes a space-saving photovoltaic double-skin façade (PV-DSF) window system, which could be used in conjunction with ships to address the insufficient ship-mounted photovoltaics. In this paper, we propose a space-saving photovoltaic double-skinned façade (PV-DSF) window system that could be used in conjunction with a ship to solve the problem of insufficient space for onboard photovoltaics. According to the working principle of the system, we established a mathematical model corresponding to the actual heat transfer process and, at the same time built up a corresponding experimental test rig for thermoelectric performance measurement, and verified the accuracy of the proposed mathematical model based on the experimental results. Finally, the effect of different parameters on the performance of the system and the energy performance of the system on board the ship was discussed using a mathematical model. The simulation data showed that the increase of solar radiation intensity, wind speed, and PV coverage had a positive effect on the system’s power generation, while the ambient temperature had a negative effect. The system, in combination with a passenger ship, was able to provide 53.2 kWh of annual electricity generation and reduced CO2 emissions by 17 kg.

Impact of Spin-Entropy on the Thermoelectric Properties of a 2D Magnet.

Heat-to-charge conversion efficiency of thermoelectric materials is closely linked to the entropy per charge carrier. Thus, magnetic materials are promising building blocks for highly efficient energy harvesters as their carrier entropy is boosted by a spin degree of freedom. In this work, we investigate how this spin-entropy impacts heat-to-charge conversion in the A-type antiferromagnet CrSBr. We perform simultaneous measurements of electrical conductance and thermocurrent while changing magnetic order using the temperature and magnetic field as tuning parameters. We find a strong enhancement of the thermoelectric power factor at around the Néel temperature. We further reveal that the power factor at low temperatures can be increased by up to 600% upon applying a magnetic field. Our results demonstrate that the thermoelectric properties of 2D magnets can be optimized by exploiting the sizable impact of spin-entropy and confirm thermoelectric measurements as a sensitive tool to investigate subtle magnetic phase transitions in low-dimensional magnets.