(浙江大學(xué) 材料科學(xué)與工程系， 杭州 310027)
摘 要: 采用熱浸焊法用純Sn作為過渡層制備了P-型FeSi2/Bi2Te3梯度結(jié)構(gòu)熱電材料并對(duì)其熱電性能進(jìn)行了測(cè)試。發(fā)現(xiàn)當(dāng)熱端溫度在510℃以下時(shí)，梯度結(jié)構(gòu)熱電材料的平均Seebeck系數(shù)保持恒定，達(dá)220μV/K 至250μV/K左右，顯著高于單一均質(zhì)材料(Bi2Te3和β-FeSi2)在相同溫度范圍內(nèi)的平均Seebeck系數(shù)。梯度結(jié)構(gòu)熱電材料的輸出功率較單種材料高1.5至2倍以上，且當(dāng)材料經(jīng)190℃，100h與200h的真空退火后，輸出功率幾乎不變。金相觀察表明，在Sn層與兩半導(dǎo)體界面處，沒有明顯的Sn擴(kuò)散跡象，說明在所試驗(yàn)的條件下，用Sn作為過渡層熱穩(wěn)定性較好。
關(guān)鍵字: 熱電性能； 梯度結(jié)構(gòu)材料；輸出功率； Sn過渡層
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
