V. Kucek

Thermoelectric Properties of Cu2HgSnSe4-Cu2HgSnTe4 Solid Solution

Copper-based semiconductors from the family Cu2-II-IV-VI4 have recently attracted a great deal of attention because of their promising thermoelectric (TE) properties. Polycrystalline samples from the Cu2HgSnSexTe4−x (x = 0, 0.8, 2, 3.2, 4) solid solution were prepared and structurally characterized by powder x-ray diffraction. The samples from this solid solution crystallize in the stannite structure (space group

Thermoelectric properties and nonstoichiometry of GaGeTe

I\bar{4}2m

High-pressure vibrational and optical study of Bi2Te3

I4¯2m). Transport, TE, and thermal properties of hot-pressed samples are reported. About a 20 % reduction in calculated lattice thermal conductivities, compared to the lattice thermal conductivities of pure components of the alloys (i.e. Cu2HgSnSe4 and Cu2HgSnTe4), was observed for Cu2HgSnSe2Te2 alloy. The maximum ZT of the Cu2HgSnSe2Te2 sample reaches 0.6 at 575 K.

High‐pressure studies of topological insulators Bi2Se3, Bi2Te3, and Sb2Te3

Polycrystalline samples of composition CuIn1−xHgxTe2 (x = 0–0.21) were synthesized from elements of 5N purity using a solid state reaction. The phase purity of the products was verified by X-ray diffraction. Samples for transport property measurements were prepared using hot-pressing. The samples were characterized by measurement of the electrical conductivity, Hall coefficient, Seebeck coefficient, and thermal conductivity over a temperature range of 300–675 K. All samples show p-type conductivity. We discuss the influence of Hg substitution on the free carrier concentration and thermoelectric performance. The investigation of the thermoelectric properties shows up to a 40% improvement of ZT in the temperature range of 300–600 K.

Low-temperature transport properties of Tl-doped Bi_{2}Te_{3} single crystals

The polycrystalline samples of composition Ga1+xGe1-xTe (x = −0.03÷0.07) were synthesized from elements of 5N purity using solid state reaction. The products of synthesis were identified by X-ray diffraction. The samples for transport measurements were prepared using hot-pressing. They were characterized by the measurement of electric conductivity, Hall coefficient and Seebeck coefficient over a temperature range 80–450K and thermal conductivity over a temperature range 300-500 K. The samples show all p-type conductivity and we observe an increase in hole concentration with increasing x (content of Ga). We discuss the influence of Ga/Ge ratio on the phase purity of the samples and free carrier concentration. The investigation of thermoelectric properties shows that ZT parameter of these samples is too low at room temperature but increase distinctly with temperature.The polycrystalline samples of composition Ga1+xGe1-xTe (x = −0.03÷0.07) were synthesized from elements of 5N purity using solid state reaction. The products of synthesis were identified by X-ray diffraction. The samples for transport measurements were prepared using hot-pressing. They were characterized by the measurement of electric conductivity, Hall coefficient and Seebeck coefficient over a temperature range 80–450K and thermal conductivity over a temperature range 300-500 K. The samples show all p-type conductivity and we observe an increase in hole concentration with increasing x (content of Ga). We discuss the influence of Ga/Ge ratio on the phase purity of the samples and free carrier concentration. The investigation of thermoelectric properties shows that ZT parameter of these samples is too low at room temperature but increase distinctly with temperature.