Dual Alloying Enables High Thermoelectric Performance in AgSbTe2by Manipulating Carrier Transport Behavior

• DOI: 10.1002/adfm.202400679
• Publication Date: 2024-03-19T12:51:25Z
• Authors: Kaiqi Zhang; Shuang Liu; Xincan Wang; Shuai Wu; Qihong Xiong; Xue Wang; Junqi Chen; Guiwen Wang; Bin Zhang; Huixia Fu; Guang Han; Guoyu Wang; Xu Lu; Yun Zhou; Xiaoyuan Zhou
• Keywords: 02 engineering and technology; 0210 nano-technology

Abstract AgSbTe 2 exhibits superior thermoelectric performance in the mid‐temperature region, but its electrical properties are strongly affected by intrinsic defects and secondary phases. Distinctively, high mobility electrons still play an important role as minority carriers p‐type even below bipolarization temperature decrease Seebeck coefficient. Here, Al Se dual alloying can effectively increase hole concentration reducing cation vacancy formation energy simultaneously reduce electron suppressing n‐type Ag Te phase demonstrated, which results shift of carrier transport from two‐type to one‐type confirmed Hall measurement. Consequently, through adjusting ratio conductivity, average power factor alloyed sample is enhanced 70%. Combined with further reduced lattice thermal conductivity resulting high‐density stacking faults superstructures, a maximum zT 1.90 1.42 obtained range 323 623 K (AgSbTe ) 0.98 (AgAlSe 0.02 sample. Finally, based on finite element analysis modeling results, both single‐leg double‐leg devices fabricated, show conversion efficiency 11.2% 5.2%, respectively.