Thermoelectric performance of (AgBiTe 2 ) 1‐ x (SnTe) x with stable cubic enabled by enhanced configurational entropy

This is the authors' abstract. We don't add key points for this paper.

ABX 2 (A = Ag, Na, Cu; B = Sb, Bi; X = S, Se, Te) (Groups I‐V‐VI 2 ) compounds, which are all characterized by the ultralow lattice thermal conductivity because of their strong lattice anharmonicity caused by lone‐pair electrons, have aroused wide attention in thermoelectric community. The practical application of thermoelectric devices usually requires both the compatible n‐type and p‐type materials simultaneously. However, most of I‐V‐VI 2 compounds are intrinsic p‐type semiconductors, lacking their n‐type counterparts for thermoelectrics. Herein, in this work, we increase the configuration entropy of AgBiTe 2 by alloying SnTe, in order to stabilize the cubic phase at room temperature. With further optimization of thermal and electrical performance, the thermoelectric performance could be improved simultaneously in both n‐ and p‐type (AgBiTe 2 ) 1‐ x (SnTe) x ( x = 0.3, 0.4) solid solutions. Finally, p‐type compound with the nominal composition of (AgBi 0.99 Cd 0.01 Te 2 ) 0.6 (SnTe) 0.4 and n‐type of (AgBiTe 2 ) 0.7 (SnTe) 0.3 ~ Br 6% show the maximum zT of ~ 0.33 and ~ 0.21, at 381 and 423 K, respectively.