(浙江大学 材料科学与工程系， 杭州 310027)
摘 要: 采用热浸焊法用纯Sn作为过渡层制备了P-型FeSi2/Bi2Te3梯度结构热电材料并对其热电性能进行了测试。发现当热端温度在510℃以下时，梯度结构热电材料的平均Seebeck系数保持恒定，达220μV/K 至250μV/K左右，显著高于单一均质材料(Bi2Te3和β-FeSi2)在相同温度范围内的平均Seebeck系数。梯度结构热电材料的输出功率较单种材料高1.5至2倍以上，且当材料经190℃，100h与200h的真空退火后，输出功率几乎不变。金相观察表明，在Sn层与两半导体界面处，没有明显的Sn扩散迹象，说明在所试验的条件下，用Sn作为过渡层热稳定性较好。
关键字: 热电性能； 梯度结构材料；输出功率； Sn过渡层
segmented thermoelectric material
（Department of Materials Science and Engineering，
Zhejiang University， Hangzhou 310027, P.R.China）
Abstract: The segmented thermoelectric material of P-type β FeSi2/Bi2Te3 was prepared by means of dip coating procedure and using pure tin as the bridge material. It was found that the apparent Seebeck coefficients of the segmented materials are invariable with the applied temperature difference， and reaches an approximation of 220 to 250μV/K， which is obviously higher than those of the monolithic ones (β-FeSi2 and Bi2Te3) in the same temperature range. The measurements show that the power outputs of the segmented materials are about 1.5 to 2 times higher than that of the monolithic ones，and remain stationary even when the materials have been annealed at 190℃ 200h. The microstructure of interfaces shows no visible diffusion of tin in the semiconductor matrixes.
Key words: thermoelectric materials; functionally graded materials (FGM); power output; tin bridge material
