Structural complexity and the metal-to-semiconductor transition in lead telluride
Autor: | Christian Liebscher, Matej Bobnar, Igor Veremchuk, Iryna Zelenina, Paul Simon, Xinke Wang, Wenjun Lu, Yuri Grin |
---|---|
Jazyk: | angličtina |
Rok vydání: | 2021 |
Předmět: |
Materials science
Condensed matter physics Transition temperature Context (language use) Thermoelectric materials Molecular electronic transition Lead telluride Condensed Matter::Materials Science chemistry.chemical_compound chemistry Mechanics of Materials TA401-492 General Materials Science Dislocation Lone pair Single crystal Materials of engineering and construction. Mechanics of materials |
Zdroj: | Communications Materials, Vol 2, Iss 1, Pp 1-8 (2021) |
ISSN: | 2662-4443 |
Popis: | Lead chalcogenides are known for their thermoelectric properties since the first work of Thomas Seebeck on the discovery of this phenomenon. Yet, the electronic properties of lead telluride are still of interest due to the incomplete understanding of the metal-to-semiconductor transition at temperatures around 230 °C. Here, a temperature-dependent atomic-resolution transmission electron microscopy study performed on a single crystal of lead telluride reveals structural reasons for this electronic transition. Below the transition temperature, the formation of a dislocation network due to shifts of the NaCl-like atomic slabs perpendicular to {100} was observed. The local structure modification leads to the appearance of in-gap electronic states and causes metal-like electronic transport behavior. The dislocation network disappears with increasing temperature, yielding semiconductor-like electrical conductivity, and re-appears after cooling to room temperature restoring the metal-like behavior. The structural defects coupled to the ordering of stereochemically active lone pairs of lead atoms are discussed in the context of dislocations' formation. Lead telluride is an important thermoelectric material but its metal-to-semiconductor transition above 230 °C is not fully understood. Here, atomic-resolution transmission electron microscopy provides structural insights into this transition, explaining the metallic behavior by a dislocation network within the rock salt structure. |
Databáze: | OpenAIRE |
Externí odkaz: |