High‐temperature electrical and thermal transport behaviors in layered structure WSe₂

Abstract

Two‐dimensional transition‐metal dichalcogenides semiconductors (TMDCs) with layered structures have been concerned as promising thermoelectric (TE) materials for several years. However, WSe2 as one of TMDCs is barely investigated. Herein, we systematically investigated the high‐temperature electrical and thermal transport behaviors in layered structure WSe2, demonstrating that WSe2 possesses high Seebeck coefficient and low thermal conductivity. The study of sintering process shows that the best electrical properties can be obtained in the sample sintered at 1123 K. Besides, anisotropic thermoelectric properties were also revealed. It is found that the dimensionless figure of merit (ZT) in the direction parallel to the pressing direction is higher than that in the direction perpendicular to the pressing direction. The highest ZT value of 0.03 is obtained at 923 K, which is an appreciable value for the pristine alloy material.

Thermoelectric properties of W1−xNbxSe2−ySy polycrystalline compounds

“…In addition, the thermal conductivity ( κ ) in polycrystalline samples is always lower due to phonon scattering at crystallite boundaries. However, there are very few experimental works, evaluating the thermoelectric potential of polycrystalline transition‐metal dichalcogenides …”

“…However, there are very few experimental works, evaluating the thermoelectric potential of polycrystalline transition-metal dichalcogenides. [12][13][14][15][16][17] In our work, we investigate the polycrystalline compounds of W 1−x Nb x Se 2−y S y with partial substitutions of metal and chalcogen atoms in order to optimize the thermoelectric properties of the compound. As typical semiconductors, the undoped WSe 2 and WS 2 have a high Seebeck coefficient (S), low electrical conductivity ( ), and low thermoelectric efficiency.…”

Two-dimensional layered architecture constructing energy and phonon blocks for enhancing thermoelectric performance of InSb

“…To sum up, motivated by selecting suitable compounds, nanocompositing can artificially merge effective strategies such as PDs, nanoengineering, and energy filtering into one, which may provide an ingenious way to optimize the thermoelectric properties of other thermoelectric systems. [36] and SnSe 2 [35] systems. (b) The engineering output power density ω max and thermoelectric conversion efficiency η% dependent on hot-side temperature T h assumed by the single thermoelectric leg length L = 5 mm.…”

“…Indium powder (99.99%, Changsha Asian Light Co., Ltd.) and antimony powder (99.99%, Changsha Asian Light Co., Ltd.) were mixed in an exact metage according to nominal composition In 1.01 Sb, slowly heated to 973 K at a rate of 117 K h −1 and held at this temperature for 6 h. Then the InSb ingots were ground into fine powders in an agate mortar. As for the preparation of QSe 2 (Q = Sn, W), the acquisition of SnSe 2 was referred to the previous work [35], and the WSe 2 was obtained through the melting-quenching method [36]. The QSe 2 ingot was ground into uniform powder and performed in an ultrasonic vibrator for 6 h to obtain QSe 2 nanopowders.…”

“…Figure7(a) The ZT values vs. temperature for QSe 2 -composited InSb compared with the reported WSe 2[36] and SnSe 2[35] systems. (b) The engineering output power density ω max and thermoelectric conversion efficiency η% dependent on hot-side temperature T h assumed by the single thermoelectric leg length L = 5 mm.…”