Silver vacancy concentration engineering leading to the ultralow lattice thermal conductivity and improved thermoelectric performance of Ag_1-xInTe₂.

ABSTRACT: AgInTe₂ compound has not received enough recognition in thermoelectrics, possibly due to the fact that the presence of Te vacancy (V_Te) and antisite defect of In at Ag site (In_Ag) degrades its electrical conductivity. In this work, we prepared the Ag_1-xInTe₂ compounds with substoichiometric amounts of Ag and observed an ultralow lattice thermal conductivity (?_L?=?0.1 Wm^-1K^-1) for the sample at x?=?0.15 and 814?K. This leads to more than 2-fold enhancement in the ZT value (ZT?=?0.62) compared to the pristine AgInTe₂. In addition, we have traced the origin of the untralow ?_L using the Callaway model. The results attained in this work suggest that the engineering of the silver vacancy (V_Ag) concentration is still an effective way to manipulate the thermoelectric performance of AgInTe₂, realized by the increased point defects and modified crystal structure distortion as the V_Ag concentration increases.

SUBMITTER: Zhong Y 

PROVIDER: S-EPMC6906449 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature