Carrier density control and enhanced thermoelectric performance of Bi and Cu           co-doped GeTe

Shimano, Satoshi; Tokura, Y.; Taguchi, Y.

doi:10.1063/1.4983404

Cited by 37 publications

(31 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 7a shows the reported manipulation range of n H by different methods. [94,95,99,101,151] The data points correspond to n H of pristine GeTe and the vertical line indicates the variation range of n H in these GeTe-based materials intentionally doped/alloyed with different elements. The corresponding n H values can be effectively decreased by substitutions of Group-V metals on Ge sites, and two representative examples can be found in Ge 1−x Sb x Te [95] and Ge 1−x Bi x Te.…”

Section: Manipulation Of the Carrier Concentrationmentioning

confidence: 99%

“…[94] So far, the lowest obtained n H reaches 5.8  10 19 cm −3 in Ge 1−x−y Bi x Cu y Te, which was synthesized by melting, quenching, and spark-plasma-sintering annealing procedures to homogeneously dope a large amount of Bi and Cu into the GeTe lattice. [151] In addition to these aliovalent dopants, controlling the intrinsic Ge-vacancies can also decrease n H . As revealed in Figure 7b, Ge vacancies (V Ge ) has the lowest E form in contrast to those of the Te vacancies (V Te ) and antisite defects (Ge Te and Te Ge ) in pristine GeTe, which rationalizes the high holetype n H in GeTe.…”

Section: Manipulation Of the Carrier Concentrationmentioning

confidence: 99%

“…C-GeTe [151] Ge 1−x Sb 2x/3 Te, [101] (GeTe) 1−x (PbSe) x , [99] Ge 1−x Sb x Te, [95] Ge 1−x Bi x Te, [94] Ge 1−x Te at 300 K. [94] The data points show the reported n H for the pristine GeTe and the corresponding line shows the control range of n H by different dopants. b) Formation energies of Te vacancies (V Te ), antisite defects (Ge Te and Te Ge ), and Ge vacancies (V Ge ) in GeTe, (GeTe) 1−x (PbSe) x , [99] and Ge 1−x Sb 2x/3 Te.…”

Section: σ σ R-getementioning

confidence: 99%

“…Strategy for enhancing electronic transport by optimizing n H . a) The realized control range of Hall carrier concentration (n H ) in Ge 1−x−y Bi x Cu y Te,[151] Ge 1−x Sb 2x/3 Te,[101] (GeTe) 1−x (PbSe) x ,[99] Ge 1−x Sb x Te,[95] Ge 1−x Bi x Te,[94] Ge 1−x Te at 300 K [94]. The data points show the reported n H for the pristine GeTe and the corresponding line shows the control range of n H by different dopants.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Thermoelectric GeTe with Diverse Degrees of Freedom Having Secured Superhigh Performance

2019

View full text Add to dashboard Cite

Driven by the ability to harvest waste heat into reusable electricity and the exclusive role of serving as the power generator for deep spacecraft, intensive endeavors are dedicated to enhancing the thermoelectric performance of ecofriendly materials. Herein, the most recent progress in superhigh‐performance GeTe‐based thermoelectric materials is reviewed with a focus on the crystal structures, phase transitions, resonant bondings, multiple valance bands, and phonon dispersions. These features diversify the degrees of freedom to tune the transport properties of electrons and phonons for GeTe. On the basis of the optimized carrier concentration, strategies of alignment of multiple valence bands and density‐of‐state resonant distortion are employed to further enhance the thermoelectric performance of GeTe‐based materials. To decrease the thermal conductivity, methods of strengthening intrinsic phonon–phonon interactions and introducing various lattice imperfections as scattering centers are highlighted. An overview of thermoelectric devices assembled from GeTe‐based thermoelectric materials is then presented. In conclusion, possible future directions for developing GeTe in thermoelectric applications are proposed. The achieved high thermoelectric performance in GeTe‐based thermoelectric materials with rationally established strategies can act as a reference for broader materials to tailor their thermoelectric performance.

show abstract

Section: Manipulation Of the Carrier Concentrationmentioning

confidence: 99%

Section: Manipulation Of the Carrier Concentrationmentioning

confidence: 99%

Section: σ σ R-getementioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Thermoelectric GeTe with Diverse Degrees of Freedom Having Secured Superhigh Performance

2019

View full text Add to dashboard Cite

show abstract

“…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

View full text Add to dashboard Cite

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.

show abstract

High Entropy Semiconductor AgMnGeSbTe₄ with Desirable Thermoelectric Performance

et al. 2021

Adv Funct Materials

View full text Add to dashboard Cite

A new p-type high entropy semiconductor AgMnGeSbTe 4 with a band gap of ≈0.28 eV is reported as a promising thermoelectric material. AgMnGeSbTe 4 crystallizes in the rock-salt NaCl structure with cations Ag, Mn, Ge, and Sb randomly disordered over the Na site. Thus, a strong lattice distortion forms from the large difference in the atomic radii of Ag, Mn, Ge, and Sb, resulting in a low lattice thermal conductivity of 0.54 W m −1 K −1 at 600 K. In addition, the AgMnGeSbTe 4 exhibits a degenerate semiconductor behavior and a large average power factor of 10.36 µW cm −1 K −2 in the temperature range of 400-773 K. As a consequence, the AgMnGeSbTe 4 has a peak figure of merit (ZT) of 1.05 at 773 K and a desirable average ZT value of 0.84 in the temperature range of 400-773 K. Moreover, the thermoelectric performance of AgMnGeSbTe 4 can be further enhanced by precipitating of Ag 8 GeTe 6 , which acts as extra scatting centers for holes with low energy and phonons with medium wavelength. The simultaneous optimization in power factor and lattice thermal conductivity yields a peak ZT of 1.27 at 773 K and an average ZT of 0.92 (400-773 K) in AgMnGeSbTe 4 -1 mol% Ag 8 GeTe 6 .

show abstract

Carrier density control and enhanced thermoelectric performance of Bi and Cu co-doped GeTe

Cited by 37 publications

References 32 publications

Thermoelectric GeTe with Diverse Degrees of Freedom Having Secured Superhigh Performance

Thermoelectric GeTe with Diverse Degrees of Freedom Having Secured Superhigh Performance

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

High Entropy Semiconductor AgMnGeSbTe₄ with Desirable Thermoelectric Performance

Contact Info

Product

Resources

About

Carrier density control and enhanced thermoelectric performance of Bi and Cu co-doped GeTe

Cited by 37 publications

References 32 publications

Thermoelectric GeTe with Diverse Degrees of Freedom Having Secured Superhigh Performance

Thermoelectric GeTe with Diverse Degrees of Freedom Having Secured Superhigh Performance

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

High Entropy Semiconductor AgMnGeSbTe4 with Desirable Thermoelectric Performance

Contact Info

Product

Resources

About

High Entropy Semiconductor AgMnGeSbTe₄ with Desirable Thermoelectric Performance