P-type and N-type Bi2Te3/PbTe functional gradient materials for thermoelectric power generation

Abstract

The p-type (Bi0.2Sb0.8)2Te 3/(Pb0.7Sn0.3)Te functional gradient material (FGM) was fabricated by hot-pressing the mechanically alloyed (Bi 0.2Sb0.8)2Te3 and the 0.5 at% Na2Te-doped (Pb0.7Sn0.3)Te powders. Also, the n-type Bi2(Te0.9Se0.1)3/PbTe FGM was processed by hot-pressing the mechanically alloyed Bi2(Te 0.9Se0.1)3 and the 0.3 wt% Bi-doped PbTe powders. With ΔT larger than 300°C, the p-type (Bi 0.2Sb0.8)2Te3/(Pb 0.7Sn0.3)Te FGM exhibited larger thermoelectric output power than those of the (Bi0.2Sb0.8)2Te 3 and the 0.5 at% Na2Te-doped (Pb0.7Sn 0.3)Te alloys. For the n-type Bi2(Te0.9Se 0.1)3/PbTe FGM, the thermoelectric output power superior to those of the Bi2(Te0.9Se0.1)3 and the 0.3 wt% Bi-doped PbTe was predicted at ΔT larger than 300°C.