Lead telluride

Last updated
Lead telluride [1] [2] [3]
Names
Other names
Lead(II) telluride
Altaite
Identifiers
ChemSpider
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EC Number
  • 215-247-1
PubChem CID
UNII
Properties
PbTe
Molar mass 334.80 g/mol
Appearancegray cubic crystals.
Density 8.164 g/cm3
Melting point 924 °C (1,695 °F; 1,197 K)
insoluble
Band gap 0.25 eV (0 K)
0.32 eV (300 K)
Electron mobility 1600 cm2V1s1 (0 K)
6000 cm2V1s1 (300 K)
Structure
Halite (cubic), cF8
Fm3m, No. 225
a = 6.46 Angstroms
Octahedral (Pb2+)
Octahedral (Te2)
Thermochemistry
Std molar
entropy
(S298)
50.5 J·mol−1·K−1
-70.7 kJ·mol−1
110.0 J·mol−1·K−1
Hazards
GHS labelling:
GHS-pictogram-exclam.svg GHS-pictogram-silhouette.svg GHS-pictogram-pollu.svg
Danger
H302, H332, H351, H360, H373, H410
P201, P202, P260, P261, P264, P270, P271, P273, P281, P301+P312, P304+P312, P304+P340, P308+P313, P312, P314, P330, P391, P405, P501
Flash point Non-flammable
Safety data sheet (SDS) External MSDS
Related compounds
Other anions
Lead(II) oxide
Lead(II) sulfide
Lead selenide
Other cations
Carbon monotelluride
Silicon monotelluride
Germanium telluride
Tin telluride
Related compounds
Thallium telluride
Bismuth telluride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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PbTe unit cell PbTe unit cell.png
PbTe unit cell

Lead telluride is a compound of lead and tellurium (PbTe). It crystallizes in the NaCl crystal structure with Pb atoms occupying the cation and Te forming the anionic lattice. It is a narrow gap semiconductor with a band gap of 0.32 eV. [4] It occurs naturally as the mineral altaite.

Contents

Properties

Applications

PbTe has proven to be a very important intermediate thermoelectric material. The performance of thermoelectric materials can be evaluated by the figure of merit, , in which is the Seebeck coefficient, is the electrical conductivity and is the thermal conductivity. In order to improve the thermoelectric performance of materials, the power factor () needs to be maximized and the thermal conductivity needs to be minimized. [5]

The PbTe system can be optimized for power generation applications by improving the power factor via band engineering. It can be doped either n-type or p-type with appropriate dopants. Halogens are often used as n-type doping agents. PbCl2, PbBr2 and PbI2 are commonly used to produce donor centers. Other n-type doping agents such as Bi2Te3, TaTe2, MnTe2, will substitute for Pb and create uncharged vacant Pb-sites. These vacant sites are subsequently filled by atoms from the lead excess and the valence electrons of these vacant atoms will diffuse through crystal. Common p-type doping agents are Na2Te, K2Te and Ag2Te. They substitute for Te and create vacant uncharged Te sites. These sites are filled by Te atoms which are ionized to create additional positive holes. [6] With band gap engineering, the maximum zT of PbTe has been reported to be 0.8 - 1.0 at ~650K.

Collaborations at Northwestern University boosted the zT of PbTe by significantly reducing its thermal conductivity using ‘all-scale hierarchical architecturing'. [7] With this approach, point defects, nanoscale precipitates and mesoscale grain boundaries are introduced as effective scattering centers for phonons with different mean free paths, without affecting charge carrier transport. By applying this method, the record value for zT of PbTe that has been achieved in Na doped PbTe-SrTe system is approximately 2.2. [8]

In addition, PbTe is also often alloyed with tin to make lead tin telluride, which is used as an infrared detector material.

See also

Related Research Articles

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<span class="mw-page-title-main">Thermoelectric cooling</span> Electrically powered heat-transfer

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<span class="mw-page-title-main">Seebeck coefficient</span> Measure of voltage induced by change of temperature

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<span class="mw-page-title-main">Wiedemann–Franz law</span> Law of physics

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Lead selenide (PbSe), or lead(II) selenide, a selenide of lead, is a semiconductor material. It forms cubic crystals of the NaCl structure; it has a direct bandgap of 0.27 eV at room temperature. A grey solid, it is used for manufacture of infrared detectors for thermal imaging. The mineral clausthalite is a naturally occurring lead selenide.

<span class="mw-page-title-main">Tin selenide</span> Chemical compound

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<span class="mw-page-title-main">Mercouri Kanatzidis</span> Greek–American scientist

Mercouri Kanatzidis is a Charles E. and Emma H. Morrison Professor of chemistry and professor of materials science and engineering at Northwestern University and Senior Scientist at Argonne National Laboratory.

<span class="mw-page-title-main">Robert Chang</span> American materials scientist

Robert P. H. Chang is an American materials scientist who served as the president of the Materials Research Society (1989) and as a general secretary and president of the International Union of Materials Research Societies (IUMRS). Currently Chang heads the Materials Research Institute at Northwestern University. He is a member of advisory boards of the National Institute for Materials Science and of the journal Science and Technology of Advanced Materials.

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References

  1. Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, Florida: CRC Press, pp. 4–65, ISBN   978-0-8493-0594-8
  2. CRC Handbook, pp. 5–24.
  3. Lawson, William D (1951). "A method of growing single crystals of lead telluride and selenide". J. Appl. Phys. 22 (12): 1444–1447. doi:10.1063/1.1699890.
  4. Kanatzidis, Mercouri G. (2009-10-07). "Nanostructured Thermoelectrics: The New Paradigm? †". Chemistry of Materials. 22 (3): 648–659. doi:10.1021/cm902195j.
  5. He, Jiaqing; Kanatzidis, Mercouri G.; Dravid, Vinayak P. (2013-05-01). "High performance bulk thermoelectrics via a panoscopic approach". Materials Today. 16 (5): 166–176. doi: 10.1016/j.mattod.2013.05.004 .
  6. Dughaish, Z. H. (2002-09-01). "Lead telluride as a thermoelectric material for thermoelectric power generation". Physica B: Condensed Matter. 322 (1–2): 205–223. Bibcode:2002PhyB..322..205D. doi:10.1016/S0921-4526(02)01187-0.
  7. Biswas, Kanishka; He, Jiaqing; Zhang, Qichun; Wang, Guoyu; Uher, Ctirad; Dravid, Vinayak P.; Kanatzidis, Mercouri G. (2011-02-01). "Strained endotaxial nanostructures with high thermoelectric figure of merit". Nature Chemistry. 3 (2): 160–166. Bibcode:2011NatCh...3..160B. doi:10.1038/nchem.955. ISSN   1755-4330. PMID   21258390.
  8. Biswas, Kanishka; He, Jiaqing; Blum, Ivan D.; Wu, Chun-I.; Hogan, Timothy P.; Seidman, David N.; Dravid, Vinayak P.; Kanatzidis, Mercouri G. (2012-09-20). "High-performance bulk thermoelectrics with all-scale hierarchical architectures". Nature. 489 (7416): 414–418. Bibcode:2012Natur.489..414B. doi:10.1038/nature11439. ISSN   0028-0836. PMID   22996556. S2CID   4394616.