Enhanced thermoelectric properties of p-type argyrodites Cu8GeS6 through Cu vacancy

Synergistic Optimization of the Electronic and Phonon Transports of N-Type Argyrodite Ag8Sn1–xGaxSe6 (x = 0–0.6) through Entropy Engineering

“…Jiang et al reported a new Cu-based argyrodite-type compound Cu 8 GeSe 6 with a ZT value above 1.0 via Ag/Te dual doping . However, the argyrodite-type compounds often have complex phase transitions, such as monoclinic to orthorhombic and/or orthorhombic to cubic structures as the temperature increases, − which degrade mechanical properties of the materials. Because the cubic structure usually exhibits highly degenerate and multivalley electronic bands, ,, hence it is of great significance in thermoelectrics.…”

“…For instance, the GeSe with orthorhombic crystal structure gives a poor TE performance ( ZT ≈ 0.046) at 710 K, while the structure-engineered cubic GeSe has a peak ZT value of 0.86 . In this regard, it is important for argyrodite-type compounds to exhibit the cubic phase in the full operating temperatures. ,− ,, …”

DETERMINATION OF THERMODYNAMIC FUNCTIONS OF PHASE TRANSITION OF Cu8SiSe6 COMPOUND BY THE DSC METHOD

“…First, there are rich materials physics and materials chemistry phenomena in these phases derived from their hybrid crystal structure in which the partially occupied mobile Asublattice interpenetrates a rigid network of BX 4 tetrahedra and isolated X ions [1][2][3]. Secondly, Ag/Cu based argyrodites show themselves as promising thermoelectric materials [4][5][6][7][8][9], which is largely explained by the hierarchical structure of chemical bonds, which allows the existence of highly concentrated and highly mobile Ag + /Cu + ions distributed in a rigid polyanionic framework. On the other hand, due to the same structural feature, representatives of this class have mixed ion-electronic conductivity [10][11][12], which makes them very promising for use in the development of photoelectrode materials, electrochemical solar energy converters, ionselective sensors, etc.…”

Untitled

“…The most common and studied are argyrodites based on four and five valence elements with the general formula (Me + = Cu + , Ag + , Li + ; E 5+ = P 5+ , As 5+ ; E 4+ = Si 4+ , Ge 4+ , Sn +4 ; Hal -= Cl -, Br -, I -). These phases show superionic, ferroelastic and thermoelectric properties [10][11][12][13][14][15], which are caused by the peculiarities of the crystalline structure (the combination of rigid anionic and disordered cationic sublattice) [9]. In recent years, they have been prepared in the forms of composites, ceramics and films [16][17][18][19].…”