| 초록 |
Thermoelectric effect enables direct conversion between heat and electricity, thereby a promising means of waste heat harvesting technology. Bi2Te3-based thermoelectric materials are the most efficient system operating near room temperature. In this presentation, we investigated the thermoelectric properties of p-type Bi0.5Sb1.5Te3 – x% GeTe (x = 0, 1, 3) systems. Introducing GeTe enhances carrier concentration and suppresses lattice thermal conductivity. To optimize carrier concentration and minimize lattice thermal conductivity, ball mill process was applied to these systems. Ball milling reduces carrier concentration to the desirable level and further depresses lattice thermal conductivity, resulting in the increased ZT for 1% GeTe sample and extending high thermoelectric efficiency to the higher temperature range for 3% GeTe sample. Consequently, Bi0.5Sb1.5Te3–1% GeTe exhibits an average ZT ~0.98 from 300 to 475 K and Bi0.5Sb1.5Te3 – 3% GeTe shows a maximum ZT ~1.1 at 500 K. |
