Thermodynamic properties of tungsten diselenide in a broad temperature range

Bolgar, A. S.; Trofimova, Zh. A.; Yanaki, A.A.

doi:10.1007/bf00844959

Cited by 9 publications

(5 citation statements)

References 3 publications

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“…Next, we discuss the Te-doping effect in terms of specific-heat data below T ∼ 330 K down to approximately 1.9 K. There is no specific-heat study on the doped systems reported in the literature. For the mother compound WSe 2 , we found only one publication reporting c p data above 60 K. 62 Here we show that the analysis of the c p data provides important information about the change in the electronic states when going from W 1−x Ta x Se 2 to W 1−x Ta x Se 1.6 Te 0.4 . These data are summarized in Fig.…”

Section: Specific Heatmentioning

confidence: 61%

Modification of electronic structure and thermoelectric properties of hole-doped tungsten dichalcogenides

et al. 2015

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We present a study on the modification of the electronic structure and hole-doping effect for the layered dichalcogenide WSe2 with a multi-valley band structure, where Ta is doped on the W site along with a partial substitution of Te for its lighter counterpart Se. By means of bandstructure calculations and specific-heat measurements, the introduction of Te is theoretically and experimentally found to change the electronic states in WSe2. While in WSe2 the valence-band maximum is located at the Γ point, the introduction of Te raises the bands at the K point with respect to the Γ point. In addition, thermal-transport measurements reveal a smaller thermal conductivity at room temperature of W1−xTaxSe1.6Te0.4 than reported for W1−xTaxSe2. However, when approaching 900 K, the thermal conductivities of both systems converge while the resistivity in W1−xTaxSe1.6Te0.4 is larger than in W1−xTaxSe2, leading to comparable but slightly smaller values of the figure of merit in W1−xTaxSe1.6Te0.4.

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Section: Specific Heatmentioning

confidence: 61%

Modification of electronic structure and thermoelectric properties of hole-doped tungsten dichalcogenides

et al. 2015

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“…The temperature dependence of specific heat was taken from the Ref. . The sample density

ρ

was measured by the Archimedes method and ranged from 7.7 to 8.7 g/cm 3 .…”

Section: Methodsmentioning

confidence: 99%

“…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 …”

Section: Introductionmentioning

confidence: 99%

“…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.…”

Section: Introductionmentioning

confidence: 99%

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Thermoelectric properties of W_1−xNb_xSe_2−yS_y polycrystalline compounds

et al. 2019

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We investigate the thermoelectric properties of bulk polycrystalline samples of WSe2‐based compounds with partial substitutions in the cationic (W) and the anionic (Se) sublattices in the temperature range from 4.2 to 650 K. The substitution of W for Nb leads to a significant increase in the charge carrier concentration, however, deteriorates the charge carrier mobility. In contrast, the substitution of selenium for sulfur increases the charge carrier mobility, the thermal conductivity, and the Seebeck coefficient but conductivity changes non‐monotonical. We show that the addition of sulfur in anionic sublattice affects the grain sizes in the polycrystalline material. Using substitutions in the anionic and cationic sublattices, we find the optimal ratio of the elements for better thermoelectric efficiency. The W0.98Nb0.02Se1.7S0.3 sample showed the best value of the figure of merit ZT = 0.26 (T = 650 K).

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“…The heat capacity of the Al layer 13 and the heat capacity 14 and thermal conductivity 15 of the Si substrate are taken from literature values. The heat capacity of each sample layer is a volume weighted average of the heat capacities of the individual components: WSe 2 , 16 MoSe 2 , 17 and PbSe 19 for the misfitlayer chalcogenide samples; and Bi 2 Te 3 18 and Sb 2 Te 3 20 for the two-and three-component samples, respectively. These literature values for the components are all within 3% of the classical limit of 3 k B per atom; we used this classical value for the heat capacity of TiTe 2 because of lack of data in literature.…”

Section: Methodsmentioning

confidence: 99%

Low thermal conductivity in nanoscale layered materials synthesized by the method of modulated elemental reactants

Chiritescu

Cahill

Heideman

et al. 2008

Journal of Applied Physics

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We report the room-temperature, cross-plane thermal conductivities, and longitudinal speeds of sound of multilayer films [(TiTe2)(3)(Bi2Te3)(x)(TiTe2)(3)(Sb2Te3)(y)](i) (x=1-5, y=1-5) and misfit-layer dichalcogenide films [(PbSe)(m)(TSe2)(n)](i) (T=W or Mo, m=1-5, and n=1-5) synthesized by the modulated elemental reactants method. The thermal conductivities of these nanoscale layered materials fall below the predicted minimum thermal conductivity of the component compounds: two times lower than the minimum thermal conductivity of Bi2Te3 for multilayer [(TiTe2)(3)(Bi2Te3)(x)(TiTe2)(3)(Sb2Te3)(y)](i) films and five to six times lower than the minimum thermal conductivity of PbSe for misfit-layer dichalcogenides [(PbSe)(m)(TSe2)(n)](i). We attribute the low thermal conductivities to the anisotropic bonding of the layered crystals and orientational disorder in the stacking of layered crystals along the direction perpendicular to the surface

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Thermodynamic properties of tungsten diselenide in a broad temperature range

Cited by 9 publications

References 3 publications

Modification of electronic structure and thermoelectric properties of hole-doped tungsten dichalcogenides

Modification of electronic structure and thermoelectric properties of hole-doped tungsten dichalcogenides

Thermoelectric properties of W_1−xNb_xSe_2−yS_y polycrystalline compounds

Low thermal conductivity in nanoscale layered materials synthesized by the method of modulated elemental reactants

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Thermodynamic properties of tungsten diselenide in a broad temperature range

Cited by 9 publications

References 3 publications

Modification of electronic structure and thermoelectric properties of hole-doped tungsten dichalcogenides

Modification of electronic structure and thermoelectric properties of hole-doped tungsten dichalcogenides

Thermoelectric properties of W1−xNbxSe2−ySy polycrystalline compounds

Low thermal conductivity in nanoscale layered materials synthesized by the method of modulated elemental reactants

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Thermoelectric properties of W_1−xNb_xSe_2−yS_y polycrystalline compounds