Demonstrating the quasilocalized nature of the Sn impurity states in Bi2Te2Se
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F25%3A00635850" target="_blank" >RIV/68378271:_____/25:00635850 - isvavai.cz</a>
Result on the web
<a href="https://doi.org/10.1103/PhysRevB.111.205202" target="_blank" >https://doi.org/10.1103/PhysRevB.111.205202</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1103/PhysRevB.111.205202" target="_blank" >10.1103/PhysRevB.111.205202</a>
Alternative languages
Result language
angličtina
Original language name
Demonstrating the quasilocalized nature of the Sn impurity states in Bi2Te2Se
Original language description
Binary M2X3 compounds (M = Sb, Bi and X = S, Se, Te) and their solid solutions are among the most efficient materials for thermoelectric applications near room temperature. In the canonical compound Bi2Te3, Sn has been shown to induce a resonant level (RL) similar to 15 meV below the valence band edge, leading to enhanced thermopower values with respect to those achieved with rigidlike impurities. However, the question of whether Sn is still a resonant impurity in ternary alloys and notably, in the topological insulator Bi2Te2Se, remains unsettled. Here, we demonstrate experimentally that Sn loses its resonant character in Bi2Te2Se. Alloying with Pb in Bi1.99-ySn0.01PbyTe2Se rigidly shifts the chemical potential towards the valence bands and reveals a metal-insulator transition at low temperatures, which can be well described by an Sn impurity level that dominates the electrical conduction up to y = 0.020. Further increasing y to 0.025 and 0.030 progressively restores a conventional valence band conduction. The presence of the Sn impurity level that forms a density-of-states peak disconnected from the valence band manifold is supported by electronic band structure calculations. Due to the quasilocalized nature of this impurity level, the addition of Sn does not enhance the thermopower values compared to those measured in Sn-free samples, resulting in comparable thermoelectric performance, with a peak ZT value of 0.70 achieved at 425 K for y = 0.01.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10302 - Condensed matter physics (including formerly solid state physics, supercond.)
Result continuities
Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2025
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Physical Review B
ISSN
2469-9950
e-ISSN
2469-9969
Volume of the periodical
111
Issue of the periodical within the volume
20
Country of publishing house
US - UNITED STATES
Number of pages
16
Pages from-to
205202
UT code for WoS article
001494685200005
EID of the result in the Scopus database
2-s2.0-105005151273