Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.
Department of Materials and Optoelectronic science, National Sun Yat-sen University, Kaohsiung 80424, Taiwan.
Sci Rep. 2017 Mar 22;7:45177. doi: 10.1038/srep45177.
The thermal stability of joints in thermoelectric (TE) modules, which are degraded during interdiffusion between the TE material and the contacting metal, needs to be addressed in order to utilize TE technology for competitive, sustainable energy applications. Herein, we deposit a 200 nm-thick Zr-based thin-film metallic glass (TFMG), which acts as an effective diffusion barrier layer with low electrical contact resistivity, on a high-zT Se-doped AgSbTe substrate. The reaction couples structured with TFMG/TE are annealed at 673 K for 8-360 hours and analyzed by electron microscopy. No observable IMCs (intermetallic compounds) are formed at the TFMG/TE interface, suggesting the effective inhibition of atomic diffusion that may be attributed to the grain-boundary-free structure of TFMG. The minor amount of Se acts as a tracer species, and a homogeneous Se-rich region is found nearing the TFMG/TE interface, which guarantees satisfactory bonding at the joint. The diffusion of Se, which has the smallest atomic volume of all the elements from the TE substrate, is found to follow Fick's second law. The calculated diffusivity (D) of Se in TFMG falls in the range of D10-10(m/s), which is 1010 and 10~10 times smaller than those of Ni [10-10(m/s)] and Cu [10-10(m/s)] in BiTe, respectively.
为了将热电 (TE) 技术应用于具有竞争力的可持续能源，需要解决 TE 模块中因 TE 材料与接触金属之间的互扩散而导致的接头热稳定性问题。在此，我们在高 zT 的 Se 掺杂 AgSbTe 衬底上沉积了一层 200nm 厚的 Zr 基薄膜金属玻璃 (TFMG)，它作为一种具有低电阻的有效扩散阻挡层。将具有 TFMG/TE 的反应偶在 673 K 下退火 8-360 小时，并通过电子显微镜进行分析。在 TFMG/TE 界面处没有观察到 IMC（金属间化合物），这表明原子扩散得到了有效抑制，这可能归因于 TFMG 的无晶界结构。少量的 Se 作为示踪剂，在 TFMG/TE 界面附近发现了均匀的富 Se 区，保证了接头的良好结合。来自 TE 衬底的所有元素中原子体积最小的 Se 的扩散被发现遵循菲克第二定律。在 TFMG 中 Se 的扩散系数 (D) 落在 D10-10(m/s) 的范围内，分别比 BiTe 中 Ni[10-10(m/s)]和 Cu[10-10(m/s)]的扩散系数小 1010 和 10~10 倍。
