Elusive β-Zn<sub>8</sub>Sb<sub>7</sub>: A New Zinc Antimonide Thermoelectric

Wang, Jian; Kovnir, Kirill

doi:10.1021/jacs.5b08214

Cited by 45 publications

(71 citation statements)

References 41 publications

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“…In other words, the value of n p0 would be on the order of magnitude of 10 18 -10 19 cm À3 . From the fitting data, we can safely make a conclusion that the experimental data are in line with eqn (6), confirming that our approximation is physically reasonable. This allows us to discuss the consequence of the bipolar effect.…”

Section: View Article Onlinesupporting

confidence: 81%

“…Here the n eff data are evaluated from a comparison between measured s and calculated s e (by setting the majority carriers as electrons) or s h (by setting the majority carriers as holes). (b) The evaluated n eff data are fitted using eqn (6) and the evaluated x(T) curve from eqn (7) is also plotted. (c) The consistency between the calculated S(T) and measured S(T) data is determined using the effective carrier concentration n eff .…”

Section: Bipolar Effectmentioning

confidence: 99%

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] The TE conversion efficiency and performance-price ratios of TE devices developed so far and those under development are insufficient to compete with fossil fuel based energy resources. Some intrinsic issues need to be solved for TE materials design and synthesis, and some of them have been lasting for decades.…”

Section: Introductionmentioning

confidence: 99%

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Investigation of the bipolar effect in the thermoelectric material CaMg₂Bi₂ using a first-principles study

Gong

Hong

Shuai

et al. 2016

Phys. Chem. Chem. Phys.

111

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The bipolar effect in relatively narrow band-gap thermoelectric (TE) compounds is a negative process deteriorating the TE properties particularly at higher temperatures. In this work, we investigate the TE performance of the compound CaMg2Bi2 using the first-principles calculation and semi-classical Boltzmann transport theory in combination with our experimental data. It is revealed that this compound exhibits a remarkable bipolar effect and temperature-dependent carrier concentration. The bipolar effect imposes remarkable influence on all the electron-transport related TE parameters. An effective carrier concentration neff as a function of temperature is proposed to account for the bipolar effect induced carrier excitations. The as-evaluated TE parameters then show good consistency with measured results. This work may shed light on our understanding of the bipolar effect in TE compounds.

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Section: View Article Onlinesupporting

confidence: 81%

Section: Bipolar Effectmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Investigation of the bipolar effect in the thermoelectric material CaMg₂Bi₂ using a first-principles study

Gong

Hong

Shuai

et al. 2016

Phys. Chem. Chem. Phys.

111

View full text Add to dashboard Cite

show abstract

“…When abundant heat is supplied at low cost, TE modules with high PF materials could be more commercially viable at present because they can consistently produce a large output power density under the given temperature gradient. [28][29][30][31][32][33][34] The surprising example is tin monoselenide (SnSe), which had not been considered for TE applications because of seemingly high electrical resistivity. [16][17][18][19][20][21][22] Recently, PbSe-based TE materials have also been greatly improved with new innovative strategies.…”

Section: Introductionmentioning

confidence: 99%

Cu Intercalation and Br Doping to Thermoelectric SnSe₂ Lead to Ultrahigh Electron Mobility and Temperature‐Independent Power Factor

Zhou

Zhang

et al. 2019

Adv Funct Materials

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Due to its single conduction band nature, it is highly challenging to enhance the power factor of SnSe 2 by band convergence. Here, it is reported that simultaneous Cu intercalation and Br doping induce strong Cu-Br interaction to connect SnSe 2 layers, otherwise isolated, via "electrical bridges." Atom probe tomography analysis confirms a strong attraction between Cu intercalants and Br dopants in the SnSe 2 lattice. Density functional theory calculations reveal that this interaction delocalizes electrons confined around SnSe covalent bonds and enhances charge transfer across the SnSe 2 slabs. These effects dramatically increase electron mobility and concentration. Polycrystalline SnCu 0.005 Se 1.98 Br 0.02 shows even higher electron mobility than pristine SnSe 2 single crystal and the theoretical expectation. This results in significantly improved electrical conductivity without reducing effective mass and Seebeck coefficient, thereby leading to the highest power factor of ≈12 µW cm −1 K −2 to date for polycrystalline SnSe 2 and SnSe. It even surpasses the value for the state-of-the-art n-type SnSe 0.985 Br 0.015 single crystal at elevated temperatures. Surprisingly, the achieved power factor is nearly independent of temperature ranging from 300 to 773 K. The engineering thermoelectric figure of merit ZT eng for SnCu 0.005 Se 1.98 Br 0.02 is ≈0.25 between 773 and 300 K, the highest ZT eng ever reported for any form of SnSe 2 -based thermoelectric materials.

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“…[29][30][31][32][33][34][35] A computationally derived convex hull of formation enthalpies for various binary zinc antimonides predicts ZnSb to have the most negative formation enthalpy. 36 Low-temperature, soft chemistry techniques may provide a reproducible means to observe and isolate many of these compounds.…”

Section: Introductionmentioning

confidence: 99%

Expanding the I–II–V Phase Space: Soft Synthesis of Polytypic Ternary and Binary Zinc Antimonides

et al. 2018

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Soft chemistry methods offer the possibility of synthesizing metastable and kinetic products that are unobtainable through thermodynamically-controlled, high-temperature reactions. A recent solution-phase exploration of Li-Zn-Sb phase space revealed a previously unknown cubic half-Heusler MgAgAs-type LiZnSb polytype. Interestingly, this new cubic phase was calculated to be the most thermodynamically stable, despite prior literature reporting only two other ternary phases (the hexagonal half-Heusler LiGaGe-type LiZnSb, and the full-Heusler Li2ZnSb). This surprising discovery, coupled with the intriguing optoelectronic and transport properties of many antimony containing Zintl phases, required a thorough exploration of syn-thetic parameters. Here, we systematically study the effects that different precursor concentrations, injection order, nucleation and growth temperatures, and reaction time have on the solution-phase synthesis of these materials. By doing so, we identify conditions that selectively yield several unique ternary (c-LiZnSb vs. h*-LiZnSb), binary (ZnSb vs. Zn8Sb7), and metallic (Zn, Sb) products. Further, we find one of the ternary phases adopts a variant of the previously observed hexagonal LiZnSb struc-ture. Our results demonstrate the utility of low temperature solution phase-soft synthesis-methods in accessing and mining a rich phase space. We anticipate that this work will motivate further exploration of multinary I-II-V compounds, as well as encourage similarly thorough investigations of related Zintl systems by solution phase methods. Disciplines Materials ChemistryComments "This document is the unedited Author's version of a Submitted Work that was subsequently accepted for publication in Chemistry of Materials, copyright © American Chemical Society after peer review. To access the final edited and published work see http://dx.doi.org/10.1021/acs.chemmater.8b02910. ABSTRACT: Soft chemistry methods offer the possibility of synthesizing metastable and kinetic products that are unobtainable through thermodynamically-controlled, high-temperature reactions. A recent solution-phase exploration of Li-Zn-Sb phase space revealed a previously unknown cubic half-Heusler MgAgAs-type LiZnSb polytype. Interestingly, this new cubic phase was calculated to be the most thermodynamically stable, despite prior literature reporting only two other ternary phases (the hexagonal half-Heusler LiGaGe-type LiZnSb, and the full-Heusler Li2ZnSb). This surprising discovery, coupled with the intriguing optoelectronic and transport properties of many antimony containing Zintl phases, required a thorough exploration of synthetic parameters. Here, we systematically study the effects that different precursor concentrations, injection order, nucleation and growth temperatures, and reaction time have on the solution-phase synthesis of these materials. By doing so, we identify conditions that selectively yield several unique ternary (c-LiZnSb vs. h*-LiZnSb), binary (ZnSb vs. Zn8Sb7), and metallic (Zn, Sb) products. Furt...

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Elusive β-Zn₈Sb₇: A New Zinc Antimonide Thermoelectric

Cited by 45 publications

References 41 publications

Investigation of the bipolar effect in the thermoelectric material CaMg₂Bi₂ using a first-principles study

Investigation of the bipolar effect in the thermoelectric material CaMg₂Bi₂ using a first-principles study

Cu Intercalation and Br Doping to Thermoelectric SnSe₂ Lead to Ultrahigh Electron Mobility and Temperature‐Independent Power Factor

Expanding the I–II–V Phase Space: Soft Synthesis of Polytypic Ternary and Binary Zinc Antimonides

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Elusive β-Zn8Sb7: A New Zinc Antimonide Thermoelectric

Cited by 45 publications

References 41 publications

Investigation of the bipolar effect in the thermoelectric material CaMg2Bi2 using a first-principles study

Investigation of the bipolar effect in the thermoelectric material CaMg2Bi2 using a first-principles study

Cu Intercalation and Br Doping to Thermoelectric SnSe2 Lead to Ultrahigh Electron Mobility and Temperature‐Independent Power Factor

Expanding the I–II–V Phase Space: Soft Synthesis of Polytypic Ternary and Binary Zinc Antimonides

Contact Info

Product

Resources

About

Elusive β-Zn₈Sb₇: A New Zinc Antimonide Thermoelectric

Investigation of the bipolar effect in the thermoelectric material CaMg₂Bi₂ using a first-principles study

Investigation of the bipolar effect in the thermoelectric material CaMg₂Bi₂ using a first-principles study

Cu Intercalation and Br Doping to Thermoelectric SnSe₂ Lead to Ultrahigh Electron Mobility and Temperature‐Independent Power Factor