P-Type and N-Type Bi_2Te_3/PbTe Functional Gradient Materials for Thermoelectric Power Generation

摘要

The p-typc (Bi_(0.2)Sb_(0.8))_2Te_3/(Pb_(0.7)Sn_(0.3))Te functional gradient material (FGM) was fabricated by hot-pressing the mechanically alloyed (Bi_(0.2)Sb_(0.8))_2Te_3 and the 0.5 at% Na_2Te-doped (Pb_(0.7)Sn_(0.3))Te powders. Also, the n-type Bi_2(Te_(0.9)Se_(0.1))_3/PbTe FGM was processed by hot-pressing the mechanically alloyed Bi_2(Te_(0.9)Se_(0.1))_3 and the 0.3 wt% Bi-doped PbTe powders. With AT larger than 300 ℃, the p-type (Bi_(0.2)Sb_(0.8))_2Te_3/(Pb_(0.7)Sn_(0.3))Te FGM exhibited larger thermoelectric output power than those of the (Bi_(0.2)Sb_(0.8))_2Te_3 and the 0.5 at% Na_2Te-doped (Pb_(0.7)Sn_(0.3))Te alloys. For the n-type Bi_2(Te_(0.9)Se_(0.1))_3/PbTe FGM, the thermoelectric output power superior to those of the Bi_2(Te_(0.9)Se_(0.1))_3 and the 0.3 wt% Bi-doped PbTe was predicted at △T larger than 300℃.