| 초록 |
Thermoelectric power generators, which can directly convert thermal to electrical energy, are a promising environmentally friendly energy technology to reduce the use of fossil fuels. Recently, p-type SnSe Single crystals have shown an exceptionally high ZT of ~2.6 at 923 K along the b-axis due to anharmonic bondings. Despite the intensive researches afterward, polycrystalline SnSe still show much inferior properties with higher thermal conductivity than single crystals. In this presentation, we discuss the orgin of higher thermal conductivity in poly crystalline SnSe than the corresponding single crystals. Using transmission electron microscope, we found the presence of tin oxides embedded in the SnSe matrix even though all the preparation procedures were performed under an inert atmosphere. Then, we developed a reduction process to remove them. This reveals the intrinsically ultralow thermal conductivity in polycrystalline SnSe and a record high thermoelectric figure of merit. |
