Advances and Challenges of AgSbSe₂‐based Thermoelectric Materials

Abstract

Thermoelectric materials have aroused wide attention because of the capability to directly convert heat into electricity. AgSbSe2 is a structural analogue of PbTe but does not contain toxic element Pb or expensive element Te. Besides, it possesses both high Seebeck coefficient and inherently low thermal conductivity, making AgSbSe2 a competitive candidate for mid‐temperature thermoelectric power generation. This review summarizes the most recent updates of AgSbSe2‐based thermoelectric compounds. It starts with a general introduction of the crystal and electronic band structures of pristine AgSbSe2 with particular emphasis on the debate about whether cations arrangement is ordered or disordered. We then discuss why AgSbSe2 displays glass‐like heat conduction despite its crystalline nature. Subsequently, the strategies of boosting the electrical properties of the titled compound are elaborated. Finally, we point out the challenges and outlooks toward the future development of AgSbSe2‐based thermoelectric materials.

Enhancing the solubility of Mn in AgSbSe2 for high thermoelectric performance through entropy engineering

“…, κ tot ≤ 0.46 W m −1 K −1 ) due to the high disorder of the Ag/Sb position and the large lattice anharmonicity. 36 MnSe has a higher κ tot than AgSbSe 2 , whose κ tot is 3.4 W m −1 K −1 at 300 K. After MnSe alloying, the κ tot of (AgSbSe 2 ) 1− x (MnSe) x shows a weak change until the appearance of the high thermal conductivity secondary phase ( i.e. , precipitates of MnSe).…”

“…# 0.46 W m −1 K ) due to the high disorder of the Ag/Sb position and the large lattice anharmonicity. 36 MnSe has a higher k tot than AgSbSe 2 , whose k tot is 3.4 W m −1 K −1 at 300 K. Aer MnSe alloying, the k tot of (AgSbSe 2 ) 1−x (MnSe) x shows a weak change until the appearance of the high thermal conductivity secondary phase (i.e., precipitates of MnSe). Specically, the k tot of (AgSbSe 2 ) 0.8 (MnSe) 0.2 is 0.47 W m −1 K −1 (or 0.37 W m −1 K −1 ), compared to 0.46 W m −1 K −1 (or 0.38 W m −1 K −1 ) at 300 K (or 750 K) for AgSbSe 2 .…”

“…As a promising alternative, AgSbSe 2 has received increasing attention recently because selenium is more economical and abundant than tellurium. 36 AgSbSe 2 has intrinsically low lattice thermal conductivity due to the presence of stereochemically active solitary s 2 electron pairs on Sb and phonon scattering of highly disordered Ag/Sb lattices. [37][38][39] However, AgSbSe 2 has relatively poor electrical performance due to the lack of charge carriers, which hinders the improvement of its thermoelectric performance.…”

“…37–39 However, AgSbSe 2 has relatively poor electrical performance due to the lack of charge carriers, which hinders the improvement of its thermoelectric performance. 36,40 So far, doping univalent (Na + (ref. 41 )), divalent (Mg 2+ , 42 Mn 2+ , 39 Pb 2+ , 43 and Sn 2+ (ref.…”

Surface Chemistry and Band Engineering in AgSbSe2: Toward High Thermoelectric Performance

“…The combination of its intrinsically low κ and appropriate energy band structure makes AgSbSe 2 an ideal candidate for TE applications. Nevertheless, the main drawback of AgSbSe 2 is its moderate σ associated with an insufficient charge carrier concentration (10 16 –10 18 cm –3 ) at room temperature . Thus, the TE performance of AgSbSe 2 can be enhanced considerably by increasing the carrier concentration and properly engineering its electronic band structure …”