[12p-A407-1~4] 16.2 Energy Harvesting

▲ [12p-A407-3] Improved thermoelectric performance of p-type Si-Ge alloy

〇(PC)Omprakash Muthusamy¹, Saurabh Singh^1,3, Masahiro Adachi², Yoshiyuki Yamamoto², Tsunehiro Takeuchi^1,3,4,5 (1.Research Center for Smart Energy Technology, Toyota Technological Institute, Nagoya 468-8511, Japan, 2.Sumitomo Electric Industries, Ltd., Hyogo 664-0016, Japan, 3.CREST, Japan Science and Technology Agency, Toyota Technological Institute, Tokyo 102-0076, Japan, 4.MIRAI, Japan Science and Technology Agency, Toyota Technological Institute, Tokyo 102-0076, Japan, 5.Institute of Innovation for Future Society, Nagoya University, Nagoya 464-8603, Japan)

Keywords:Si-Ge, ball milling, thermoelectric property

In order to improve the figure of merit ZT, many strategies have been reported. For example, nano-structuring and modulation doping approach has been utilized to improve the thermoelectric properties of Si-Ge alloy by decreasing thermal conductivity without degrading the power factor.
Our previous studies revealed that B-doped Si-Ge-Au thin film and bulk sample possessed ZT value of 1.38 and 1.63 at 1000K. We found that the electron transport properties were constructively improved using Au-doping to form an impurity level near the valence band top, and B-doping to control the Fermi level. Very small thermal conductivity ~ 1.5 Wm^-1K^-1 was obtained due to nanograins. However, Au is an expensive element and more than ZT = 1.63 is required for improving efficiency. In the present study, we synthesized bulk noncrystalline B-doped Si-Ge alloy with other metal substitution, which is a cheap and non-toxic element. Thermoelectric properties of bulk nanocrystalline samples were investigated as a function of temperature 300 – 1000 K, respectively.