Influence of Se Substitution in GeTe on Phase and Thermoelectric Properties

Yang, Liangliang; Li, J. Q.; Chen, Renkun; Li, Y.; Liu, F. S.; Ao, W.Q.

doi:10.1007/s11664-016-4770-4

Cited by 32 publications

(47 citation statements)

References 27 publications

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“…The Bi and Sb have been widely used to reduce the hole concentration of GeTe due to their donor dopant nature. [ 29–33 ] Other doping or alloying with Pb, [ 25,34–36 ] Se, [ 30,37–39 ] Bi‐Sb, [ 40 ] Bi‐Cu, [ 41 ] Mn‐Bi, [ 42 ] Mn‐Sb, [ 43 ] Pb‐Sb, [ 28,44 ] Pb‐Bi, [ 45 ] Cd‐Bi, [ 46,47 ] Sb‐Zn, [ 48 ] Sb‐In, [ 49 ] Bi 2 Te 3 , [ 23,26 ] Sb 2 Te 3 , [ 50 ] and AgSbTe 2 [ 51,52 ] have also been widely applied to optimize the carrier density and to reduce κ lat for enhancing the ZT of GeTe‐based alloys. Combined with the synergic effects of carrier‐density optimization, band engineering and phonon engineering strategies, many GeTe‐based alloys with peak ZT of around 2 have been reported recently.…”

Section: Introductionmentioning

confidence: 99%

Positive Effect of Ge Vacancies on Facilitating Band Convergence and Suppressing Bipolar Transport in GeTe‐Based Alloys for High Thermoelectric Performance

Ding

et al. 2020

Adv Funct Materials

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Because the intrinsic Ge vacancies in GeTe usually lead to high hole concentration beyond the optimal range, many previous studies tend to consider Ge vacancies as negative effects on increasing the figure of merit ZT of GeTe-based alloys, and consequently have proposed various approaches to suppress Ge vacancies. However, in this work, it is demonstrated that the Ge vacancies can have great positive effects on enhancing the ZT of GeTe-based alloys when the hole concentration falls into the optimal range. First, hole concentration of GeTe is reduced close to the optimal range by co-alloying of Pb and Bi, and then the Ge vacancies are increased by adding excess Te into the Ge 0.8 Pb 0.1 Bi 0.1 Te 1+x . The Ge vacancies can cause lattice shrinkage and promote rhombohedral-to-cubic phase transition. As revealed by firstprinciple calculations, theoretical simulations, and experimental tests, Ge vacancies can facilitate the band convergence, suppress the bipolar transport at higher temperature range, and reduce the lattice thermal conductivity. Combining these effects, a peak ZT of 1.92 at 637 K and an average ZT of 1.34 within 300-773 K in Ge 0.8 Pb 0.1 Bi 0.1 Te 1.06 can be obtained, demonstrating the great significance of utilizing vacancy-type defects for enhancing ZT.

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Section: Introductionmentioning

confidence: 99%

Positive Effect of Ge Vacancies on Facilitating Band Convergence and Suppressing Bipolar Transport in GeTe‐Based Alloys for High Thermoelectric Performance

Ding

et al. 2020

Adv Funct Materials

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“…Some of the strategies for GeTe based materials to enhance the power factor and/or to suppress latt have been adopted on compositions such as GeTe-AgSbTe2 (TAGS), 31 GeTe-LiSbTe2, 32 GeTe-AgInTe2, 33 GeTe-AgSbSe2, 34 (GeTe)nSb2Te3, 35 Ge1-xPbxTe, 36 Ge1-xBixTe, 37 (Bi2Te3)nGe1-xPbxTe, 38 Ge1-xInxTe, 39 GeTe1-xSe, 40 Ge1-…”

Section: Introductionmentioning

confidence: 99%

Realizing a stable high thermoelectric zT ∼ 2 over a broad temperature range in Ge_1−x−yGa_xSb_yTe via band engineering and hybrid flash-SPS processing

Srinivasan

Gellé

Gucci

et al. 2019

Inorg. Chem. Front.

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“…For GeTe, many substituents have been tested in order to improve its transport properties. It has been shown that incorporating Se (Yang et al, 2016;Perumal et al, 2016) influences the thermoelectric properties of GeTe and leads to an increase in the figure of merit, ZT, of up to 26% in the temperature range 300-800 K.…”

Section: Introductionmentioning

confidence: 99%

New insights on the GeSe _x Te_1−x phase diagram from theory and experiment

Herrmann

Stoffel

Küpers

et al. 2019

Acta Crystallogr Sect B

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The high-pressure and low-temperature behaviour of the GeSe x Te 1Àx system (x = 0, 0.2, 0.5, 0.75, 1) was studied using a combination of powder diffraction measurements and first-principles calculations. Compounds in the stability field of the GeTe structure type (x = 0, 0.2, 0.5) follow the high-pressure transition pathway: GeTe-I (R3m) ! GeTe-II (f.c.c.) ! GeTe-III (Pnma). The newly determined GeTe-III structure is isostructural to -GeSe, a high-pressure and high-temperature polymorph of GeSe. Pressure-dependent formation enthalpies and stability regimes of the GeSe x Te 1Àx polymorphs were studied by DFT calculations. Hexagonal Ge 4 Se 3 Te is stable up to at least 25 GPa. Significant differences in the high-pressure and low-temperature behaviour of the GeTetype structures and the hexagonal phase are highlighted. The role of GeÁ Á ÁGe interactions is elucidated using the crystal orbital Hamilton population method. Finally, a sketch of the high-pressure phase diagram of the system is provided.

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Influence of Se Substitution in GeTe on Phase and Thermoelectric Properties

Cited by 32 publications

References 27 publications

Positive Effect of Ge Vacancies on Facilitating Band Convergence and Suppressing Bipolar Transport in GeTe‐Based Alloys for High Thermoelectric Performance

Positive Effect of Ge Vacancies on Facilitating Band Convergence and Suppressing Bipolar Transport in GeTe‐Based Alloys for High Thermoelectric Performance

Realizing a stable high thermoelectric zT ∼ 2 over a broad temperature range in Ge_1−x−yGa_xSb_yTe via band engineering and hybrid flash-SPS processing

New insights on the GeSe _x Te_1−x phase diagram from theory and experiment

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Influence of Se Substitution in GeTe on Phase and Thermoelectric Properties

Cited by 32 publications

References 27 publications

Positive Effect of Ge Vacancies on Facilitating Band Convergence and Suppressing Bipolar Transport in GeTe‐Based Alloys for High Thermoelectric Performance

Positive Effect of Ge Vacancies on Facilitating Band Convergence and Suppressing Bipolar Transport in GeTe‐Based Alloys for High Thermoelectric Performance

Realizing a stable high thermoelectric zT ∼ 2 over a broad temperature range in Ge1−x−yGaxSbyTe via band engineering and hybrid flash-SPS processing

New insights on the GeSe x Te1−x phase diagram from theory and experiment

Contact Info

Product

Resources

About

Realizing a stable high thermoelectric zT ∼ 2 over a broad temperature range in Ge_1−x−yGa_xSb_yTe via band engineering and hybrid flash-SPS processing

New insights on the GeSe _x Te_1−x phase diagram from theory and experiment