A and B site doping of a phonon-glass perovskite oxide thermoelectric

Daniels, Luke M.; Ling, Sanliang; Саввин, С.Н.; Pitcher, Michael J.; Dyer, Matthew S.; Claridge, JB; Slater, Ben; Corà, Furio; Alaria, Jonathan; Rosseinsky, M. J.

doi:10.1039/c8ta03739f

Cited by 23 publications

(22 citation statements)

References 49 publications

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“…As a result, thermal and electrical properties usually increase and decrease in unison, yielding little to no net change in zT. A major challenge in the field of thermoelectrics is to decouple these properties to obtain an overall enhancement in zT, thereby increasing efficiency [1,2,[6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Implications of doping on microstructure, processing, and thermoelectric performance: The case of PbSe

Grovogui

Slade

Hao

et al. 2021

Journal of Materials Research

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In this work, we highlight the often-overlooked effects of doping on the microstructure and performance of bulk thermoelectric materials to offer a broader perspective on how dopants interact with their parent material. Using PbSe doped with Na, Ag, and K as a model material system, we combine original computational, experimental, and microscopy data with established trends in material behavior, to provide an in-depth discussion of the relationship between dopants, processing, and microstructure, and their effects on thermoelectric efficiency and thermal stability. Notable observations include differences in the microstructure and mass loss of thermally treated samples of Na- and Ag-doped PbSe, as well as findings that Na and K cations exist predominantly as substitutional point defects while Ag also occupies interstitial sites and exhibits lower solubility. We discuss how these differences in point defect populations are known to affect a dopants’ ability to alter carrier concentration and how they may affect the mechanical properties of PbSe during processing. Graphic Abstract

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Section: Introductionmentioning

confidence: 99%

Implications of doping on microstructure, processing, and thermoelectric performance: The case of PbSe

Grovogui

Slade

Hao

et al. 2021

Journal of Materials Research

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“…(2.09 µW cm -1 K -2 at 373 K, tilt angle 2.18°) and La0.5Na0.5Ti0.9Nb0.1O3 (4.25 µW cm -1 K -2 at 373 K, with tilt angle 7.45°). 16,17 The power factor is found to be dependent on cell volume and ionic radii of rare elements in the rare-earth substituted STO (Sr0.9R0.1TiO3±d) with tetragonal cells, 19 which might also be related to the effects of octahedral titling. As shown in Figure 1b, the frontier orbitals of STO are formed of Ti 3d-t2g and O 2p orbitals.…”

Section: Introductionmentioning

confidence: 98%

“…[13][14][15] The realization of phonon-glass electron-crystal (PGEC) behavior in titanate perovskite systems, such as La0.5Na0.5Ti1-xNbxO3, La1-yKyTiO3 and La0.5K0.5Ti1-xNbxO3, achieves thermal conductivities as low as ~2.30 W m -1 K -1 at room temperature, which are 75%-80% lower than STO. 16,17 Following this incorporation of A site disorder, the power factor does not remain as high as STO; for example, the power factor of La0.5K0.5Ti0.95Nb0.05O3 (~5 µW cm -1 K -2 ) is about one sixth that of La doped STO. 6,17 Therefore, despite substantial efforts and success in reducing the thermal conductivity, questions remain on how to best optimize the thermoelectric power factor of titanate perovskites.…”

Section: Introductionmentioning

confidence: 99%

“…16,17 Following this incorporation of A site disorder, the power factor does not remain as high as STO; for example, the power factor of La0.5K0.5Ti0.95Nb0.05O3 (~5 µW cm -1 K -2 ) is about one sixth that of La doped STO. 6,17 Therefore, despite substantial efforts and success in reducing the thermal conductivity, questions remain on how to best optimize the thermoelectric power factor of titanate perovskites.…”

Section: Introductionmentioning

confidence: 99%

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Effects of Octahedral Tilting on Band Structure and Thermoelectric Power Factor of Titanate Perovskites: A First-Principles Study on SrTiO₃

et al. 2020

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Doped SrTiO3 and other perovskite structured titanates are attracting interest as n-type thermoelectric materials due to their relatively high thermoelectric power factor, low toxicity and modest cost. Taking SrTiO3 as an exemplar, the effects of octahedral tilting on the electronic band structure and thermoelectric power factor of titanate perovskites have been studied from first-principles calculations. By utilizing Glazer's notation, six representative tilt systems, including three out-of-phase (a 0 a 0 c -, a 0 bb -, and aaa -) and three in-phase tilt systems (a 0 a 0 c + , a 0 b + b + , and a + a + a + ), were investigated. It is found that out-of-phase tilting improves the optimum power factor as compared to the cubic aristotype, while in-phase tilting marginally lowers the optimum power factor. The largest increase in power factor (~100%) is obtained in the one-tilt system a 0 a 0 cat a tilt angle of 15°, which can be achieved with an energy cost of only 44 kJ mol -1 per formula unit. These findings agree with the experimental evidence that increased power factors are found in a 0 a 0 cand aaatilt systems of titanate perovskites. The predicted increase of Seebeck coefficient as a function of tilt angle in the aaatilt system of SrTiO3 is also consistent with experimental increase of Seebeck coefficient in aaatitanates of La0.55K0.45TiO3 and La0.5Na0.5Ti0.9Nb0.1O3. Our simulations provide valuable insights into tuning the thermoelectric power factor of titanate perovskite by controlling octahedral tilting.

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“…Metal oxide thermoelectric (TE) materials have tremendous potential for waste heat recovery from automotive exhaust systems and industrial furnaces because they are chemically stable at high temperatures, and also offer robust physical properties. [ 1 ] The performance of TE materials is assessed by the dimensionless figure of merit,

z T = \frac{S^{2} σ}{κ} T

, where, S, σ, T , and κ are the Seebeck coefficient which is also known as the thermo‐power, the electrical conductivity, the absolute temperature, and the thermal conductivity respectively. [ 2–5 ] The term S 2 σ is called the power factor of the TE material.…”

Section: Introductionmentioning

confidence: 99%

Significant Reduction in Thermal Conductivity and Improved Thermopower of Electron‐Doped Ba_1–_xLa_xTiO₃ with Nanostructured Rectangular Pores

Ahmed

Cortie

Yun

et al. 2021

Adv Elect Materials

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Electron‐doped BaTiO3 is a less studied n‐type metal oxide thermoelectric material. In this work, the electrical conductivity of BaTiO3 samples has been improved by introducing La to yield an n‐type Ba1–xLaxTiO3 semiconducting material. Density functional theory calculations show that the optimal electron‐doping occurs at x = 0.2, and this is also confirmed experimentally. To improve the thermoelectric properties further, nanostructured cuboidal pores are introduced into the bulk Ba1–xLaxTiO3 using F127 surfactant micelles for a chemical templating process, followed by spark plasma sintering. Interestingly, transmission electron microscopy images and X‐ray powder diffraction analysis confirms that our fabricated samples are cubic BaTiO3 perovskite phase with the nanostructured rectangular‐prism pores of >4 nm. Scanning electron microscopy images show that all the samples have similar grain boundaries and uniform La doping, which suggests that the large reduction in the lattice thermal conductivity in the F127‐treated samples arises primarily from the pore distribution, which introduces anisotropic phonon scattering within the unique nanoarchitecture. The sample with 20 at% La doping and nanopores also shows a thermopower that is doubled compared to the related sample without porosity. Together with the lattice thermal conductivity, enables a significant improvement in figure of merit, zT compared to the other samples.

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A and B site doping of a phonon-glass perovskite oxide thermoelectric

Abstract: The effect of structural symmetry is investigated in phonon-glass electron-crystal (PGEC) La1−yKyTiO3 and La0.5K0.5Ti1−zNbzO3 thermoelectric oxides

Cited by 23 publications

References 49 publications

Implications of doping on microstructure, processing, and thermoelectric performance: The case of PbSe

Implications of doping on microstructure, processing, and thermoelectric performance: The case of PbSe

Effects of Octahedral Tilting on Band Structure and Thermoelectric Power Factor of Titanate Perovskites: A First-Principles Study on SrTiO₃

Significant Reduction in Thermal Conductivity and Improved Thermopower of Electron‐Doped Ba_1–_xLa_xTiO₃ with Nanostructured Rectangular Pores

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A and B site doping of a phonon-glass perovskite oxide thermoelectric

Abstract: The effect of structural symmetry is investigated in phonon-glass electron-crystal (PGEC) La1−yKyTiO3 and La0.5K0.5Ti1−zNbzO3 thermoelectric oxides

Cited by 23 publications

References 49 publications

Implications of doping on microstructure, processing, and thermoelectric performance: The case of PbSe

Implications of doping on microstructure, processing, and thermoelectric performance: The case of PbSe

Effects of Octahedral Tilting on Band Structure and Thermoelectric Power Factor of Titanate Perovskites: A First-Principles Study on SrTiO3

Significant Reduction in Thermal Conductivity and Improved Thermopower of Electron‐Doped Ba1–xLaxTiO3 with Nanostructured Rectangular Pores

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Product

Resources

About

Effects of Octahedral Tilting on Band Structure and Thermoelectric Power Factor of Titanate Perovskites: A First-Principles Study on SrTiO₃

Significant Reduction in Thermal Conductivity and Improved Thermopower of Electron‐Doped Ba_1–_xLa_xTiO₃ with Nanostructured Rectangular Pores