Zhong Yaqiong, Luo Yong, Li Xie, Cui Jiaolin
School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou, 221116, China.
School of Materials and Chemical Engineering, Ningbo University of Technology, Ningbo, 315211, China.
Sci Rep. 2019 Dec 11;9(1):18879. doi: 10.1038/s41598-019-55458-3.
AgInTe compound has not received enough recognition in thermoelectrics, possibly due to the fact that the presence of Te vacancy (V) and antisite defect of In at Ag site (In) degrades its electrical conductivity. In this work, we prepared the AgInTe compounds with substoichiometric amounts of Ag and observed an ultralow lattice thermal conductivity (κ = 0.1 WmK) 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 AgInTe. In addition, we have traced the origin of the untralow κ using the Callaway model. The results attained in this work suggest that the engineering of the silver vacancy (V) concentration is still an effective way to manipulate the thermoelectric performance of AgInTe, realized by the increased point defects and modified crystal structure distortion as the V concentration increases.
AgInTe化合物在热电领域尚未得到足够的认可，这可能是由于Te空位（V）的存在以及In在Ag位点的反位缺陷（In）会降低其电导率。在这项工作中，我们制备了Ag含量不足化学计量比的AgInTe化合物，并观察到在x = 0.15和814 K时该样品的晶格热导率超低（κ = 0.1 WmK）。这导致与原始AgInTe相比，ZT值（ZT = 0.62）提高了两倍多。此外，我们使用Callaway模型追踪了超低κ的来源。这项工作所取得的结果表明，通过增加点缺陷以及随着V浓度增加改变晶体结构畸变，调控银空位（V）浓度仍然是操纵AgInTe热电性能的有效方法。
