Cu2Se类液态热电材料扩散阻挡层的研究

Investigation on the Barrier Layer of Cu2Se Liquid-Like Thermoelectric Material

首先选用Mo作为Cu2Se的扩散阻挡层材料,通过一步法热压烧结制备了Cu2Se/Mo/Cu2Se三明治结构样品,发现Cu2Se/Mo异质界面具有极低的界面接触电阻率。但是,Cu2Se/Mo界面结合强度较差,不利于器件的长时间稳定工作。随后,通过在Mo层中引入活性元素Mn,利用Mn在Cu2Se中易于扩散的特点,在保持极低界面接触电阻率的同时,显著提高了异质界面的结合强度。高温长时间老化后,Cu2Se/Mo-Mn界面仍然保持良好的界面结合和低的界面接触电阻率。表明Mo-Mn金属混合相是与Cu2Se材料相匹配的扩散阻挡层,可用以开发具有良好服役性能的Cu2Se基热电器件。

Cu2Se/Mo/Cu2Se thermoelectric joints were fabricated by the one-step hot pressing method using Mo as the barrier layer for Cu2Se.It is found that the Cu2Se/Mo interface has ultralow electrical contact resistivity but poor tensile strength.Via introducing 5%(mass fraction)Mn in Mo,the tensile strength is improved by three times while still maintaining low electrical contact resistivity,which are attributed to the diffusion of Mn in Cu2Se during the hot pressing process.The evolutions of microstructure and contact resistivity at the interface during long-term aging at high temperatures(650 and 800℃)were investigated.After aging experiments,the interface remains integrity with low contact resistivity,which proves that the Mo-Mn mixed phase is a promising candidate as the barrier layer for Cu2Se-based thermoelectric generators.