Year: 2019
Type: article
Abstract: Composed of inexpensive and naturally abundant elements, the chalcopyrite mineral CuFeS2 has received attention as a potentially useful thermoelectric. We use first-principles electronic structure and Boltzmann transport theory calculations to investigate thermoelectric properties of n-doped CuFeS2. We find that energy-dependent carrier lifetimes that are inversely proportional to the electronic density-of-states are crucial for reproducing experimental data on the transport properties, including the measured values of the Seebeck coefficient, α. The heavy-effective-mass conduction band promotes high values of α, but it also leads to low mobility due to strong electron-acoustic-phonon scattering. Low mobility forces one to rely on high carrier concentration to achieve high conductivity, which decreases α and limits the achievable power factor. Our calculations predict that ideally doped CuFeS2 that has been nanostructured to an average grain size d≈20nm can attain thermoelectric figures of merit zT=0.25 to 0.8 for T=300 to 700 K, respectively, due to a reduction in the lattice thermal conductivity.
Source: Journal of Applied Physics
DOI: 10.1063/1.5088165
Authors: Junsoo Park, Yi Xia, Vidvuds Ozoliņš
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2941879819