Sulfide Perovskites for Thermoelectricity.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid State Chemistry

Background:

• Developing efficient thermoelectric materials for waste heat recovery is crucial.
• Experimental screening of novel thermoelectric compounds is costly and time-consuming.

Purpose of the Study:

• To systematically screen for novel, stable, and synthesizable ABQ3 compounds as potential thermoelectric materials.
• To identify promising candidates with high thermoelectric performance and favorable material properties.

Main Methods:

• First-principles density functional theory (DFT) calculations were employed for systematic screening.
• Electronic band structure analysis was performed to understand thermoelectric properties.
• Boltzmann transport equation and anharmonic lattice dynamics were used to calculate lattice thermal conductivity.

Main Results:

• 40 ABQ3 compounds were predicted to be competent thermoelectric materials, featuring non-toxic and earth-abundant elements.
• Several compounds demonstrated power factors comparable to or exceeding those of PbTe and Bi2Te3.
• An ultralow lattice thermal conductivity was validated, attributed to anharmonicity and soft phonon modes.

Conclusions:

• The ABQ3 family offers a promising avenue for highly efficient n-type and p-type thermoelectric materials.
• The combination of high power factor and low thermal conductivity suggests practical applications.
• These materials exhibit anisotropic characteristics and possess favorable thermal and moisture stability.