Excellent Thermoelectric Properties Research Articles

Self-Powered Machine-Learning-Assisted Material Identification Enabled by a Thermogalvanic Dual-Network Hydrogel with a High Thermopower.

Wearable devices equipped with high-performance flexible sensors that can identify diverse physical information free from batteries are playing an indispensable role in various fields. However, previous studies on flexible sensors have primarily focused on their elasticity and temperature-sensing capability, with few reports on material identification. In this paper, a thermogalvanic dual-network hydrogel is fabricated with [Fe(CN)6]3-/4- as a redox couple and lithium magnesium silicate, Gdm+ and lithium bromideas key electrolytes to optimize the interconnected porous structure of the gel, which shows excellent mechanical and thermoelectric properties with a thermopower as high as 4.01mV K-1. A self-powered material identification ring is developed based on the temperature-triggered thermoelectric response of the gel in conjunction with machine learning, which can actively infer materials without an external power connection by analyzing the voltage signals correlated with interfacial heat transfer produced upon contact with different materials. The proposed gel ring has important applications for future areas such as human-computer interaction and haptic-associated artificial intelligence.

High‐performance thermoelectric calcium cobaltite nanoribbon ceramic via electrospinning and dual spark plasma texturing

AbstractHigh‐performance polycrystalline calcium cobaltite ceramic was synthesized via electrospinning of nanoribbons, followed by dual‐process compaction using spark plasma sintering and edge‐free spark plasma texturing. The combination of nanoribbon electrospinning and this multistage sintering technique was employed for the first time and resulted in exceptionally well‐textured thermoelectric ceramics. The textured ceramic had excellent thermoelectric properties. At 1073 K, the ceramic exhibited an electrical conductivity of 268 S cm−1, a Seebeck coefficient of 247 µV K−1 and a heat conductivity of 3.3 W m−1 K−1. In addition, the power factor and figure‐of‐merit reached enormously high values of 16.3 µW cm−1 K−2 and 0.53, respectively. This represents the highest thermoelectric performance reported to date not only for electrospun, polycrystalline calcium cobaltite fiber ceramics, but also for undoped polycrystalline calcium cobaltite ceramics.

Patternable and flexible thermoelectric generators based on Bi2Te3/silk fibroin composites for temperature sensing and wearable applications

Thermoelectric (TE) materials are functional materials that can directly convert heat energy into electrical energy, and have a positive effect on alleviating the energy crisis. Inorganic semiconductor materials have attracted extensive attention due to their excellent TE properties, among which Bi2Te3 is the best and most widely used inorganic TE material at room temperature. However, inorganic TE materials are still restricted by unfavorable factors such as scarcity of raw material resources, heavy metal pollution, high price, high rigidity, and complex processing technology, which greatly limit their development process. Therefore, it is urgent to develop flexible TE materials with high performance, non-polluting, non-toxic and low price. The combination of silk fibroin and inorganic TE materials not only retains the properties of TE materials, but also improves their flexibility. Here, the Bi2Te3/SF TE films are successfully fabricated by the evaporation-assisted self-assembly method with Seebeck coefficient of 199 μV⋅K−1 (p-type) and −240 μV⋅K−1 (n-type). In order to verify the feasibility of collecting and utilizing ambient heat energy in real life, the Bi2Te3/SF TE films are cut into various patterns (such as, flower, rabbit, tree, etc) to collect wasted ambient heat. Further, the Bi2Te3/SF thermoelectric generator (TEG) reaches a maximum power of 21 nW at a temperature difference of 43.5 K. A series of self-power temperature sensing demonstrations from single TE film, TEG, to TEG array are proposed to demonstrate their potential applications in the field of self-power sensors. Finally, by inserting Bi2Te3/SF TEG array into a bracelet, a self-powered smart bracelet can be successfully constructed, demonstrating the feasibility of the Bi2Te3/SF TE film in the development of self-powered wearable electronics.

Thermoelectric properties of superionic Li0.11Cu1.89S compound

Copper sulfide is a multifunctional material. Copper sulfides are known to be used in photo-electric converters, in plasmonics, in active electrodes of batteries and supercapacitors, etc. The excellent thermoelectric properties of copper sulfide are well-known too. The purpose of this study is to investigate the thermoelectric performance of nanocomposite copper sulfide contained monoclinic Cu2S and tetragonal Cu1.96S phase. According to scanning electron microscopy, the average particle size of the synthesized powder was about 373 nm. The Li0.11Cu1.89S sample showed an electronic conductivity of 50–180 S/cm, a Seebeck coefficient of 0.04–0.31 mV/K in the range of 300–700 K, and high power factor 5.8 μW K−2cm−1 at 672 K. Total thermal conductivity decreases with increasing temperature from 0.61 to 0.22 W∙K−1m−1 in the range of 300–700 K. Such low thermal conductivity and high power factor made it possible to achieve an extremely high dimensionless thermoelectric figure of merit ZT = 1.76 at 672 K, which allows to consider the Li0.11Cu1.89S alloy as a promising thermoelectric material.

Novel Tl2GeX6 (X=Cl,Br) Double Perovskites for Solar Cell, Optoelectronic, and Thermoelectric Applications: A DFT Investigation

This study aims to investigate the structural, mechanical, optical, electronic, and thermoelectric properties of novel double perovskites Tl2GeCl6 and Tl2GeBr6. The Quantum Espresso code was employed to perform the Density Functional Theory (DFT) calculation on the perovskites’ characteristics. The results indicated that both materials exhibit chemical and structural stability, with equilibrium lattice constants of 10.08 Å and 10.55 Å for Tl2GeCl6 and Tl2GeBr6, respectively. The calculated elastic parameters and elastic moduli data also demonstrated that the new double perovskites exhibit mechanical stability while the calculated electronic band structure and the density of states using the PBE functional indicated that the materials are semiconductors with energy gap values of 0.3 eV for Tl2GeBr6 and 1.72 eV for Tl2GeCl6, respectively. Using more accurate SCAN approximation, the energy gaps were refined to 0.53 eV for Tl2GeBr6 and 2.10 eV for Tl2GeCl6. Additionally, the calculated dielectric functions, extinction coefficient and absorption coefficients of Tl2GeCl6 and Tl2GeBr6 strongly suggest the exceptional optical response of these materials. Notably, Tl2GeBr6 is estimated to have a particularly strong visible-light absorption capacity, positioning it as a promising absorber for perovskite solar cells. These findings are also supported by the low reflectivity values observed. Finally, the analysis of their thermoelectric properties revealed the excellent thermoelectric properties of Tl2GeCl6 and Tl2GeBr6, as indicated by their high figures of merit, predicted to be 0.73 and 0.68 for the respective perovskites.

Complementary resistive switching characteristics of solid electrolyte chalcogenide AgxTe nanoparticles for high-density crossbar random access memory

Silver telluride (AgxTe) is a member of the chalcogenide family that comprises materials extensively used as solid electrolytes. Because of its high-ionic conductivity, low-optical bandgap, and excellent thermoelectric properties, AgxTe has been studied in many research fields, including optoelectronics and energy harvesting. Herein, AgxTe is proposed as the active channel for resistive random access memory (RRAM) showing complementary resistive switching (CRS) characteristics. AgxTe-based RRAM devices with an Ag/AgxTe/Au structure are fabricated on a glass substrate. AgxTe nanoparticles are synthesized using the colloidal method, and AgxTe thin films are prepared via spin coating of the synthesized nanoparticles dispersed in deionized water. The fabricated AgxTe-based RRAM device exhibits CRS characteristics without any additional built-in selectors or antiserial arrangement. This is attributed to the formation of the inversion of CF geometry and allows the fabrication of high-density crossbar arrays. The AgxTe RRAM device annealed at 200 °C exhibits a resistance on/off ratio of approximately 102 as well as stable retention (∼104 s) and endurance (∼103 cycles). This investigation proposes a new application of AgxTe, as a solid electrolyte, and a new strategy for the development of high-density crossbar RRAM architectures, for the first time.

Stretchable Ag2Se Thermoelectric Fabric with Simple and Nonthermal Fabrication for Wearable Electronics

As the field of wearable electronics continues to expand, the integration of inorganic thermoelectric (TE) materials into fabrics has emerged as a promising development due to their excellent TE properties. However, conventional thermal methods for fabricating TE fabrics are unsuitable for wearable applications because of their high temperatures, resulting in rigid TE materials. Herein, a nonthermally fabricated silver selenide (Ag2Se) TE fabric is developed that can be effectively integrated into wearable applications. Ag2Se nanoparticles are densely formed within the fabric through a simple in situ chemical reduction process, resulting in remarkable electrical stability even after 10 000 cycles of mechanical deformation, such as stretching and compression. Notably, the fabricated Ag2Se TE fabric exhibits superior stretchability, stretching ≈1.36 times more than the thermally treated Ag2Se TE fabrics, while retaining its excellent electrical conductivity. Moreover, the TE unit exhibits 9.80 μW m−1 K−2 power factor, 134.45 S cm−1 electrical conductivity, and −26.98 μV K−1 Seebeck coefficient at 370 K. A haptic sensing glove based on the Ag2Se TE fabric as a sensor for detecting potential hazards is demonstrated. The glove effectively distinguishes between simple touch, physical pain, and high‐temperature hazards, ensuring user safety and prompt response.

Synergistic effect of bonding heterogeneity and phonon localization in introducing excellent thermoelectric properties in layered heteroanionic NdZnSbO material

Layered rare-earth metal oxides, harnessing the dual properties of oxides and two-dimensional layered materials, exhibit remarkable thermal stability and quantum confinement effects. Therefore, this work adopts the first-principles calculation combined with the Boltzmann transport theory to predict the thermoelectric properties of NdZnSbO compound. The coexistence of weak interlayer van der Waals interactions, robust intralayer ionic bonding, and partial covalent bonding leads to remarkable bonding heterogeneity, which engenders pronounced phonon scattering and imposes constraints on thermal transport along the out-of-plane direction. The weakened chemical bonds induced by the antibonding states, together with the rattling-like behavior of the Zn atom, culminate in the profound anharmonicity in the layered NdZnSbO compound. The weakening bond and heavy element contribute to the softness of phonon modes, which significantly diminishes the phonon group velocity. The redistribution-dominated four-phonon scattering process spans a large optical gap, which effectively reduces the lattice thermal conductivity. The NdZnSbO compound exhibits direct semiconductor characteristic with a bandgap of 0.73 eV by adopting the Heyd-Scuseria-Ernzerhof (HSE06) functional in combination with spin–orbit coupling (SOC) effect. The multi-valley feature of NdZnSbO compound augur favorably for band degeneracy, thus amplifying the power factor. Consequently, an optimal figure-of-merit (ZT) of 3.40 at 900 K is achieved for the n-type NdZnSbO compound. The present study delves deeply insights into the origins for the low thermal conductivity of NdZnSbO compound and proposes an optimization scheme to enhance overall thermoelectric performance.

Orientation optimization for high performance Mg3Sb2 thermoelectric films via thermal evaporation

Low-cost, highly efficient thermoelectric thin-film materials are becoming increasingly popular as miniaturization progresses. Mg3Sb2has great potential due to its low cost and high performance. However, the fabrication of Mg3Sb2thin films with high power factors (PFs) poses a certain challenge. In this work, we propose a general approach to prepare Mg3Sb2thin films with excellent thermoelectric properties. Using a two-step thermal evaporation and rapid annealing process, (001)-oriented Mg3Sb2thin films are fabricated onc-plane-oriented Al2O3substrates. The structure of the film orientation is optimized by controlling the film thickness, which modulates the thermoelectric performance. The PF of the Mg3Sb2at 500 nm (14μW·m-1·K-2) would increase to 169μW·m-1·K-2with Ag doping (Mg3Ag0.02Sb2) at room temperature. This work provides a new strategy for the development of high-performance thermoelectric thin films at room temperature.

Excellent thermoelectric properties and significant anisotropy for filled-tetragonal NaZnAs caused by strong anharmonicity

We have theoretically investigated the transport properties of the filled-tetrahedral NaZnAs using first-principles calculations in combination with self-consistent phonon theory and the Boltzmann transport equation. The results show that the transport behavior of NaZnAs exhibits obvious anisotropy, and the influence of quartic anharmonicity on the lattice thermal conductivity cannot be neglected as shown by the thermal conductivity results obtained from different computational models. Both the increase in scattering rates(SRs) and the decrease in group velocity signify a strong anharmonicity. We further find that the special vibrational modes due to the weak bonding of Zn atoms are the main source of anharmonicity. We find that considering the bubble diagram for the phonon self-energy correction reduces the κL by up to 28.04% at 700 K, which favors the capture of large ZT values. In addition, The ZT value of NaZnAs can reach 3.07 at 700 K, which shows great potential for thermoelectric applications.

Thermoelectric Properties Regulated by Quantum Size Effects in Quasi-One-Dimensional γ-Graphdiyne Nanoribbons.

Using density functional theory combined with the first principles calculation method of non-equilibrium Green's function (NEGF-DFT), we studied the thermoelectric (TE) characteristics of one-dimensional γ-graphdiyne nanoribbons (γ-GDYNRs). The study found that the thermal conductivity of γ-GDYNRs has obvious anisotropy. At the same temperature and geometrical size, the lattice thermal conductivity of zigzag-edged γ-graphdiyne nanoribbons (γ-ZGDYNRs) is much lower than that of armchair-edged γ-graphdiyne nanoribbons (γ-AGDYNRs). We disclose the underlying mechanism for this intrinsic orientation. That is, γ-AGDYNRs have more phonon dispersion over the entire frequency range. Furthermore, the orientation dependence increases when the width of the γ-GDYNRs decreases. These excellent TE properties allow armchair-edged γ-graphdiyne nanoribbons with a planar width of 1.639 nm (γ-Z(2)GDYNRs) to have a higher power factor and lower thermal conductivity, ultimately resulting in a significantly higher TE conversion rate than other γ-GDYNR structures.

Comparison of the excellent thermoelectric properties of the half-Heusler compounds RbMgSb with a host-guest structure and LiMgSb

In this work, we systematically studied the thermoelectric (TE) transport properties of the half-Heusler compounds AMgSb (A = Li, Rb) based on an incorporation of first-principles calculations with self-consistent phonon theory and Boltzmann transport equations. We noted significant changes in the vibrational behavior of alkali metal atoms with a substantial increase in atomic mass. This alteration led to the formation of a host-guest structure in RbMgSb. In contrast, the stronger harmonic vibrations in LiMgSb results in it maintaining a Half-Heusler structure, without the pronounced anharmonicity found in RbMgSb. The calculation results reveal that RbMgSb has ultra-low lattice thermal conductivity κL, which is ten times lower than LiMgSb. We show that rattlers cause tenfold reductions in the thermal conductivity by increasing the phonon–phonon scattering probability, occurred in a wide frequency range. In addition, after careful consideration of multiple scattering mechanisms, the multiple valleys, high dispersion, flat band edges and band asymmetry near the Fermi level give both materials excellent electron transport properties. At the same time, LiMgSb itself already has a very low electron thermal conductivity κe, but the κe of RbMgSb is ten times smaller than that. As a consequence, remarkable ZT values of 2.51 and 3.45 at 900 K are captured in n-type LiMgSb and p-type RbMgSb, respectively. These findings reveal the promising potential of AMgSb in TE applications.

Influence of Sputtering Power on the Properties of Magnetron Sputtered Tin Selenide Films.

The ecofriendly tin selenide (SnSe) is expected to find multiple applications in optoelectronic, photovoltaic, and thermoelectric systems. This work is focused on the thermoelectric properties of thin films. SnSe single crystals exhibit excellent thermoelectric properties, but it is not so in the case of polycrystalline bulk materials. The investigations were motivated by the fact that nanostructuring may lead to an improvement in thermoelectric efficiency, which is evaluated through a dimensionless figure of merit, ZT = S2 σ T/λ, where S is the Seebeck coefficient (V/K), σ is the electrical conductivity (S/m), λ is the thermal conductivity (W/mK), and T is the absolute temperature (K). The main objective of this work was to obtain SnSe films via magnetron sputtering of a single target. Instead of common radiofrequency (RF) magnetron sputtering with a high voltage alternating current (AC) power source, a modified direct current (DC) power supply was employed. This technique in the classical version is not suitable for sputtering targets with relatively low thermal and electrical conductivity, such as SnSe. The proposed solution enabled stable sputtering of this target without detrimental cracking and arcing and resulted in high-quality polycrystalline SnSe films with unprecedented high values of ZT equal to 0.5 at a relatively low temperature of 530 K. All parameters included in ZT were measured in one setup, i.e., Linseis Thin Film Analyzer (TFA). The SnSe films were deposited at sputtering powers of 120, 140, and 170 W. They had the same orthorhombic structure, as determined by X-ray diffraction (XRD), but the thickness and microstructure examined by scanning electron microscopy (SEM) were dependent on the sputtering power. It was demonstrated that thermoelectric efficiency improved with increasing sputtering power and stable values were attained after two heating-cooling cycles. This research additionally provides further insights into the DC sputtering process and opens up new possibilities for magnetron sputtering technology.

Suppressing the thermal conductivity to enhance the thermoelectric performance of SnSe2 using the high-energy ball milling in a pressurised N2 atmosphere

Two-dimensional (2D) layered dichalcogenides possess excellent thermoelectric (TE) properties. Among them, tin diselenide (SnSe2) exhibits n-type semiconducting properties with attractive TE performance near room temperature (RT). However, its high thermal conductivity and relatively low electrical conductivity have limited its TE performance for practical applications. In this study, we significantly suppressed the thermal conductivity and enhanced the TE performance of 2D layered SnSe2 polycrystalline structures by reducing the particle size to the nano-scale using the high-energy ball milling (BM) technique in a pressurised N2 atmosphere. The particle size was reduced from ∼2 μm to 100 nm after 15 h of BM. TE results of a highly pressed compact leg made from the TE-optimised BM sample (e.g. 7 h) showed that at RT, the electrical conductivity increased by a factor of 9, whereas the Seebeck coefficient was reduced by only 40%. Consequently, the power factor increased from 12 to 42 μW/m·K2. In addition, the thermal conductivity decreased from 5.72 to 0.40 W/m·K, resulting in a significant increase in the figure of merit by a factor of 40 times higher than that of the non-BM SnSe2 leg. This study also demonstrated power generation using single-leg modules made from these structures at ΔT values above and below RT. The TE power generation of the BM module was found to be much higher than that of the non-BM module, particularly below RT. The 7-h BM module generated 2600 nW at ΔT = 45 K above RT, but when the same ΔT was applied below RT, the generated power reached 8000 nW. This enhancement in power generation below RT is remarkable, suggesting that the BM SnSe2 compact may be useful for generating measurable TE power in cold environments.

Enhancing thermoelectric properties of higher manganese silicide through facilitated non-equilibrium reactions via the introduction of additional Carbon nano-dots

Higher manganese silicide (HMS) has gained significant attention as a compelling choice for thermoelectric (TE) applications at medium temperatures due to its abundance, environmental friendliness, and impact resistance properties. Recent achievement in HMS involves leveraging the synergistic effect of energy filtering, modulation doping, and boundary scattering to enhance the TE performance. However, excellent TE properties on HMS usually demands extreme preparation processes such as shock compression, melt spinning technique, or chemical vapor transport approach, as well as the use of rare and expensive elements or nano-dots (NDs), such as Re, Ge, Ag/Pt alloy, or CsPbBr3 quantum dots. In this study, a facile wet ball milling combing with spark plasma sintering is used to streamline the synthesis processes. Relatively green, cost-effective, and accessible C NDs are used to facilitated non-equilibrium reactions and enhance TE properties of HMS. Due to the C-doped effect, the PF increased from 1.42 to 1.62 mW m−1 K−2 at 723 K, representing an approximately 14 % improvement compared to the pristine HMS. The introduction of C, derived SiC and Mn NDs result in the enhancing phonon scattering, and leading to a reduction in lattice thermal conductivity from 2.21 to 1.81 W m−1 K−1. Consequently, the figure of merit (zT) increases from 0.42 to 0.55 at 823 K, representing an enhancement of approximately ∼ 31 %. Predictably, the incorporation of C NDs into semiconductors stands as one of the effective strategies for enhancing the TE properties.

AI-driven ensemble learning for accurate Seebeck coefficient prediction in half-Heusler compounds based on chemical formulas

Half-Heusler compounds with their unique crystal structure and tunable properties show excellent thermoelectric properties. As a result, these compounds hold great potential for many applications such as thermoelectric devices and energy conversion technologies. This paper presents a machine learning study on developing ensemble learning models to accurately predict the Seebeck coefficient at ambient temperature and arbitrary carrier concentration for both n-type and p-type half-Heusler compounds, based only on their chemical formula. Ensemble learning algorithms proved to be effective regression models for identifying hidden relationships. All models displayed satisfactory performance under 10-fold cross-validation and achieved high R-squared values ranging from 0.87 to 0.95 and low MAE values ranging from 20.8 μV/K to 37.04 μV/K. Among ensemble models, the GBoost shows the best performance for p-type with an R2 value of 0.95. On the other hand, for n-type the Light GBoost and CatBoost models yielded the best results with R2 = 0.94. Ultimately, we validated the accuracy of the model outputs through rigorous Density Functional Theory (DFT) calculations, wherein these models demonstrated their remarkable effectiveness in precisely predicting the Seebeck coefficients for half-Heusler compounds. This research holds significant potential in facilitating the screening of materials for thermoelectric devices, which heavily rely on the critical Seebeck coefficient parameter. The ability to accurately predict this key property can accelerate the identification of promising candidate materials, driving advancements in thermoelectric technology and paving the way for more efficient energy conversion and management solutions.

Control of interfacial reaction and defect formation in Gd/Bi2Te2.7Se0.3 composites with excellent thermoelectric and magnetocaloric properties

Abstract The method to combine thermoelectric (TE) and magnetocaloric (MC) cooling techniques lies in developing a new material that simultaneously possesses a large TE and good MC cooling performance. In this work, using n-type Bi2Te2.7Se0.3 (BTS) as the TE base material and Gd as the second-phase MC material, Gd/BTS composites were prepared by the spark plasma sintering method. In the composites, interfacial reaction between Gd and BTS was identified, resulting in the formation of GdTe, which has a large impact on the electron concentration through the adjustment of defect concentration. The MC/TE composite containing 2.5 wt% Gd exhibited a ZT value of 0.6 at 300 K, essentially retaining the original TE performance, while all the composites largely maintained the excellent MC performance of Gd. This work provides a potential pathway to achieving high performance in MC/TE composites.

Theoretical Insight into the Band Alignment at High-κ Oxide XO2/Diamond (X = Hf and Zr) Interfaces with a SiO2 Interlayer for MOS Devices.

Diamond has become a promising candidate for high-power devices based on its ultrawide bandgap and excellent thermoelectric properties, where an appropriate gate dielectric has been a bottleneck hindering the development of diamond devices. Herein, we have systematically investigated the structural arrangement and electronic properties of diamond/high-κ oxide (HfO2, ZrO2) heterojunctions by first-principles calculations with a SiO2 interlayer. Charge analysis reveals that the C-Si bonding interface attracts a large amount of charge concentrated at the diamond interface, indicating the potential for the formation of a 2D hole gas (2DHG). The diamond/HfO2 and diamond/ZrO2 heterostructures exhibit similar "Type II" band alignments with VBOs of 2.47 and 2.21 eV, respectively, which is consistent with experimental predictions. The introduction of a SiO2 dielectric layer into the diamond/SiO2/high-κ stacks exhibits the typical "Type I″ straddling band offsets (BOs). In addition, the wide bandgap SiO2 interlayer keeps the valence band maximum (VBM) and conduction band minimum (CBM) in the stacks away from those of diamond, effectively confining the electrons and holes in MOS devices. This work exhibits the potential of SiO2/high-κ oxide gate dielectrics for diamond devices and provides theoretical insights into the rational design of high-quality gate dielectrics for diamond-based MOS device applications.

Dual Sensing Signal Decoupling Based on Thermoelectric Polymer Aerogels for Precise Temperature and Pressure Recognition

AbstractThe capability to emulate skin‐like temperature and pressure sensing is fundamental for next‐generation artificial intelligence products. However, detecting temperature and pressure simultaneously with a single sensor without signal interference is challenging. Herein, a novel PCC aerogel sensor composed of PEDOT:PSS, CNTs, and CNF via directional freezing technology is developed. The PCC sensor can decouple temperature and pressure stimuli into individual voltage and resistance signals. It exhibits high‐precision temperature sensing capabilities, boasting an exceptionally high Seebeck coefficient of 30.4 µV K‐1 and the ability to detect temperature variations as low as 0.1 K. PCC sensors show excellent sensitivity and fast response times for detecting static and dynamic pressures, as well as high stability after 1000 cycles. Its maximum pressure sensitivity can reach 159.1% kPa−1, and the lowest detection limit is 10 Pa. Additionally, its excellent thermoelectric properties also enable to generating thermopower from human skin for self‐powered pressure sensing. A 3×3 PCC sensor array has been proposed to simulate the unique features of human skin in temperature and pressure recognition. This work provides a scalable manufacturing strategy for multi‐functional tactile sensors.

Thermoelectric properties and thermal transport in two-dimensional GaInSe3 and GaInTe3 monolayers: A first-principles study

We here report the electronic structure calculation of GaInSe3 and GaInTe3 monolayers with the P3m1 (no. 156) space group. The electronic structure and thermoelectric properties of the monolayers are calculated through the Vienna Ab initio Simulation Package and BoltzTraP2 codes. The dynamic and thermodynamic stabilities were verified by calculating their phonon spectra and simulating ab initio molecular dynamics. The monolayers were found to have a direct bandgap, with both PBE + SOC and HSE06 + SOC potentials. The lattice thermal conductivity of GaInTe3 monolayer calculated using Phono3py code shows ultra-low values due to enhanced phonon–phonon scattering. Combining electrical and thermal transport, the values have been evaluated. Importantly, the p-type GaInTe3 has excellent thermoelectric properties at 700 K, with a zT value of 2, indicating that the p-type GaInTe3 has potential application in the field of thermoelectricity.