Details

Autor(en) / Beteiligte

• Troppenz, Maria
• Rigamonti, Santiago
• Sofo, Jorge O
• Draxl, Claudia

Titel

Partial Order-Disorder Transition Driving Closure of Band Gap: Example of Thermoelectric Clathrates

Ist Teil von

• Physical review letters, 2023-04, Vol.130 (16), p.166402-166402, Article 166402

Ort / Verlag

United States

Erscheinungsjahr

2023

Quelle

EZB Free E-Journals

Beschreibungen/Notizen

• In the quest for efficient thermoelectrics, semiconducting behavior is a targeted property. Yet, this is often difficult to achieve due to the complex interplay between electronic structure, temperature, and disorder. We find this to be the case for the thermoelectric clathrate Ba_{8}Al_{16}Si_{30}: Although this material exhibits a band gap in its ground state, a temperature-driven partial order-disorder transition leads to its effective closing. This finding is enabled by a novel approach to calculate the temperature-dependent effective band structure of alloys. Our method fully accounts for the effects of short-range order and can be applied to complex alloys with many atoms in the primitive cell, without relying on effective medium approximations.