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We investigated the effects on thermoelectric properties of Cu doping in Fe2‐xCuxVAl at Fe site of full‐Heusler type compound. It is found that the Cu doping for Fe sites causes a significant increase in the absolute value of Seebeck coefficient |S| and a decrease in thermal conductivity. The Seebeck coefficient (S)=‐148μV/K and the Power factor (PF)=4.0 mWK−2m−1 have been observed for Fe1.9Cu0.1VAl (x=0.1) at 300 K. To further improve it, we fixed the Cu doping level at x=0.1 in Fe2‐xCuxVAl and co‐doped the material with Si at Al site, namely, Fe1.9Cu0.1VAl1‐ySiy. The thermoelectric properties have been improved by Si doping to a certain limit. We observed a decrease in electrical resistivity and lattice thermal conductivity by Si doping for Al. The maximum power factor of 4.5 mWK−2m−1 has been achieved for Fe1.9Cu0.1Al0.9Si0.1 at 350 K. More precisely, the thermoelectric performance has been improved with co‐doping of Cu for Fe sites and Si for Al sites. The largest ZT value is 0.13 for Fe1.9Cu0.1VAl1‐ySiy (y=0.15). Magnetic susceptibility suggests that all the measured compounds are showing paramagnetic behavior. The magnetic character is the most pronounced in Fe1.9Cu0.1VAl among the materials investigated, pointing to a possible correlation between the magnetic character due to electronic correlation and the larger Seebeck coefficient in this sample. [ABSTRACT FROM AUTHOR]

Alongiside the growing demand for wearable and implantable electronics, the development of flexible thermoelectric (FTE) materials holds great promise and has recently become a highly necessitated and efficient method for converting heat to electricity. Conductive polymers were widely used in previous research; however, n-type polymers suffer from instability compared to the p-type polymers, which results in a deficiency in the n-type TE leg for FTE devices. The development of the n-type FTE is still at a relatively early stage with limited applicable materials, insufficient conversion efficiency, and issues such as an undesirably high cost or toxic element consumption. In this work, as a prototype, a flexible n-type rare-earth free skutterudite (CoSb3)/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS) binary thermoelectric film was fabricated based on ball-milled skutterudite via a facile top-down method, which is promising to be widely applicable to the hybridization of conventional bulk TE materials. The polymers bridge the separated thermoelectric particles and provide a conducting pathway for carriers, leading to an enhancement in electrical conductivity and a competitive Seebeck coefficient. The current work proposes a rational design towards FTE devices and provides a perspective for the exploration of conventional thermoelectric materials for wearable electronics. [ABSTRACT FROM AUTHOR]

Cover Feature: Thermoelectric properties of Cu-Doped Heusler compound Fe2-xCuxVAl (Z. Anorg. Keywords: Heusler compounds; Electrical resistivity; Seebeck coefficient; Thermal conductivity; ZT EN Heusler compounds Electrical resistivity Seebeck coefficient Thermal conductivity ZT 1 1 1 08/19/22 20220812 NES 220812 The cover picture shows co-doping of Cu for Fe and Si for Al site in Fe SB 2 sb VAl, and the effect of Cu doping to significantly enhance the thermoelectric power factor. Heusler compounds, Electrical resistivity, Seebeck coefficient, Thermal conductivity, ZT. [Extracted from the article]

In this work, a series of Bi2Te3/X mol% MoS2 (X = 0, 25, 50, 75) bulk nanocomposites were prepared by hydrothermal reaction followed by reactive spark plasma sintering (SPS). X-ray diffraction analysis (XRD) indicates that the native nanopowders, comprising of Bi2Te3/MoS2 heterostructure, are highly reactive during the electric field-assisted sintering by SPS. The nano-sized MoS2 particles react with the Bi2Te3 plates matrix forming a mixed-anion compound, Bi2Te2S, at the interface between the nanoplates. The transport properties characterizations revealed a significant influence of the nanocomposite structure formation on the native electrical conductivity, Seebeck coefficient, and thermal conductivity of the initial Bi2Te3 matrix. As a result, enhanced ZT values have been obtained in Bi2Te3/25 mol% MoS2 over the temperature range of 300–475 K induced mainly by a significant increase in the electrical conductivity. [ABSTRACT FROM AUTHOR]

Filled skutterudites are currently studied as promising thermoelectric materials due to their high power factor and low thermal conductivity. The latter property, in particular, can be enhanced by adding scattering centers, such as the ones deriving from low dimensionality and the presence of interfaces. This work reports on the synthesis and characterization of thin films belonging to the Smy(FexNi1−x)4Sb12-filled skutterudite system. Films were deposited under vacuum conditions by the pulsed laser deposition (PLD) method on fused silica substrates, and the deposition temperature was varied. The effect of the annealing process was studied by subjecting a set of films to a thermal treatment for 1 h at 423 K. Electrical conductivity σ and Seebeck coefficient S were acquired by the four-probe method using a ZEM-3 apparatus performing cycles in the 348–523 K temperature range, recording both heating and cooling processes. Films deposited at room temperature required three cycles up to 523 K before being stabilized, thus revealing the importance of a proper annealing process in order to obtain reliable physical data. XRD analyses confirm the previous result, as only annealed films present a highly crystalline skutterudite not accompanied by extra phases. The power factor of annealed films is shown to be lower than in the corresponding bulk samples due to the lower Seebeck coefficients occurring in films. Room temperature thermal conductivity, on the contrary, shows values comparable to the ones of doubly doped bulk samples, thus highlighting the positive effect of interfaces on the introduction of scattering centers, and therefore on the reduction of thermal conductivity. [ABSTRACT FROM AUTHOR]

An in-depth analysis of Cu 2+ x Co 1- x GeS 4 (CCGS) has been performed to illustrate its potential as a new p -type compound for thermoelectric (TE) applications with suitable thermal stability. An intrinsic semiconductor behavior is reported with attractive TE properties, characterized by a large Seebeck coefficient and intrinsic low thermal conductivity. Band structures and elastic properties calculations sustained the experimental observations and revealed the dominant role of Cu/Co ratio in electrical transport properties. A promising TE performance is achieved through a carrier concentration tuning by Cu/Co ratio control, with a zT = 0.37 at 725 K resulting from combined large PF enhancement and a reduced κ. • We performed the band structure and elastic properties calculations of Cu2CoGeS4 compound. • We synthesized the Cu2+ x Co1-xGeS4 (0 = x ≤ 0.225) bulk compounds series by sealed tube reaction and Spark Plasma Sintering. • We studied the structural and thermal stability of the compounds above 775 K. • The thermoelectric properties were reported and optimized up to zT = 0.37 at 725 K. • The effect of the Cu/Co ratio in the transport properties was highlighted. [ABSTRACT FROM AUTHOR]