Cui Jiaolin, Lu Yufu, Chen Shaoping, Liu Xianglian, Du Zhengliang
School of Materials & Engineering, Ningbo University of Technology Ningbo 315016 China
Materials Science and Engineering College, Taiyuan University of Technology Taiyuan 030024 China.
RSC Adv. 2018 Mar 5;8(17):9574-9579. doi: 10.1039/c8ra00316e. eCollection 2018 Feb 28.
Owing to their unique crystal and band structures, in thermoelectrics increasing attention has recently been paid to compounds of the ternary I-III-VI chalcopyrite family. In this work, unequal bonding between cation and anion pairs in Cu Ag InSeTe solid solutions, which can be effectively used to disturb phonon transport, has been proposed. The unequal bonding, which is represented by the difference of bond lengths Δ, Δ = - and anion position displacement from its equilibrium position Δ = - 0.25, is created by the isoelectronic substitution of Ag for Cu. At = 0.2 both the Δ and Δ values reach their maxima, resulting in a remarkable reduction in lattice thermal conductivity ( ) and an improvement in TE performance. However, as the value increase to 0.3 both Δ and Δ values decrease, causing the value to increase and the ZT value to decrease from 0.5 to 0.24 at 930 K. Accordingly, unequal bonding might be an alternative way to improve the TE performance of ternary chalcopyrites.
由于其独特的晶体结构和能带结构，三元I-III-VI族黄铜矿化合物在热电材料中最近受到了越来越多的关注。在这项工作中，有人提出在Cu Ag InSeTe固溶体中阳离子和阴离子对之间的不等键合可有效用于干扰声子输运。这种不等键合由Ag对Cu的等电子取代产生，用键长差Δ（Δ = - ）和阴离子相对于其平衡位置的位移Δ（Δ = - 0.25）表示。当 = 0.2时，Δ和Δ值均达到最大值，导致晶格热导率（ ）显著降低，热电性能得到改善。然而，当 值增加到0.3时，Δ和Δ值均减小，导致 值增加，在930 K时ZT值从0.5降至0.24。因此，不等键合可能是提高三元黄铜矿热电性能的一种替代方法。
