Abstract
We study the phase stability and predict as-yet-unreported compounds in the thermoelectric Cu-Sb-Se ternary system. We use a combination of total energies obtained from density-functional-theory-based (DFT) calculations with vibrational entropies from phonon calculations (within the harmonic approximation) and configurational entropies, treated with cluster expansions (CE). The Cu-Sb-Se ternary phase diagram is determined (treating all phases as line compounds) using the grand-canonical linear programming method. We find the following results: (1) we predict the stability of a new previously unknown, zinc blende-based Cu4SbSe5 compound but find that it is thermodynamically stable up to only ∼300 K; (2) we also predict that a Cu12Sb4Se13 phase (isostructural with Cu 12Sb4S13, but unreported in the Cu-Sb-Se system) appears in the phase diagram at high temperatures (but below the temperatures where the observed Cu3SbSe3 phase is stable); (3) based on quasi-harmonic phonon and band structure calculations, we find that Cu12Sb4Se13 has thermal conductivity and an electronic structure that suggests it as a promising thermoelectric material.
Original language | English (US) |
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Pages (from-to) | 3427-3435 |
Number of pages | 9 |
Journal | Chemistry of Materials |
Volume | 26 |
Issue number | 11 |
DOIs | |
State | Published - Jun 10 2014 |
ASJC Scopus subject areas
- General Chemistry
- General Chemical Engineering
- Materials Chemistry