化学镀Zn对n型Bi2Te2.4Se0.6合金热电性能的影响

为了研究化学镀Zn对n型Bi2Te2.4Se0.6材料的热电性能的影响及作用机制,采用化学镀法制备n型Zn/Bi2Te2.4Se0.6纳米粉体,并结合放电等离子烧结烧制成块体材料,n型Zn/Bi2Te2.4Se0.6热电材料的Seebeck系数(SS)提升,热导率显著降低,其中0.15％Zn/Bi2Te24Se06的热导率最低,在371 K达到最小值0.74 W/(m·K),这是由于载流子浓度的降低引起电子热导减小,以及第二相和晶界增多引起声子散射造成晶格热导降低.结果表明,0.15％Zn/Bi2Te2.4Se0.6的热电优值(ZT)有很大的提升,在421 K达到1.06.

Effect of Zn electroless plating on thermoelectric properties of n-type Bi2Te2.4Se0.6 alloy

In order to study whether electroless Zn can affect the thermoelectric properties of n-type Bi2Te2.4Se0.6 material, and by what mechanism it works, n-type Bi2Te2.4Se0.6/Zn nanopowders were prepared by electroless plating, and then sintered into bulk by spark plasma sintering. The Seebeck value of n-type Bi2Te2.4Se0.6/Zn thermoelectric material increases and the thermal conductivity decreases significantly, among which the thermal conductivity of 0.15%Zn/Bi2Te2.4Se0.6 reaches the minimum value of 0.74 W·m-1k-1 at 371 K. This is mainly attributing to the decrease of electron thermal conductivity caused by the decrease of carrier concentration, and the increase of the second phase and grain boundary causes the decrease of the lattice thermal conductivity due to the phonon scattering. The results show that the ZT value of 0.15%Zn/Bi2Te2.4Se0.6 is 1.06 at 421 K.