Improved thermoelectric performance of solid solution Cu4Sn7.5S16 through isoelectronic substitution of Se for S
Year: 2018
Type: article
Abstract: Cu-Sn-S family of compounds have been considered as very competitive thermoelectric candidates in recent years due to their abundance and eco-friendliness. The first-principles calculation reveals that the density of states (DOS) increases in the vicinity of the Fermi level ( E f ) upon an incorporation of Se in the Cu 4 Sn 7.5 S 16− x Se x ( x = 0–2.0) system, which indicates the occurrence of resonant states. Besides, the formation of Cu(Sn)-Se network upon the occupation of Se in S site reduces the Debye temperature from 395 K for Cu 4 Sn 7 S 16 ( x = 0) to 180.8 K for Cu 4 Sn 7.5 S 16− x Se x ( x = 1.0). Although the point defects mainly impact the phonon scattering, an electron-phonon interaction also bears significance in the increase in phonon scattering and the further reducion of lattice thermal conductivity at high temperatures. As a consequence, the resultant TE figure of merit (ZT) reaches 0.5 at 873 K, which is 25% higher compared to 0.4 for Cu 4 Sn 7.5 S 16 .
Source: Scientific Reports
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,690
Awards: G2713424231, G2755264318, G8600042106
OpenAlex ID: W2805477668
