The 81st JSAP Autumn Meeting, 2020

Presentation information

Oral presentation

1 Interdisciplinary Physics and Related Areas of Science and Technology » 1.4 Energy conversion, storage, resources and environment

[8p-Z22-1~14] 1.4 Energy conversion, storage, resources and environment

Tue. Sep 8, 2020 1:00 PM - 4:45 PM Z22

Kazuya Oguri(Tokai Univ.), Katsushi Fujii(RIKEN)

1:00 PM - 1:15 PM

[8p-Z22-1] High thermoelectric performance of Si-Ge alloy by modifying the electronic structure

〇(PC)Omprakash Muthusamy1, Saurabh Singh1,3, Masahiro Adachi2, Yoshiyuki Yamamoto2, Tsunehiro Takeuchi1,3,4,5 (1.Toyota Tech. Inst, 2.Sumitomo Ele. Ind., 3.CREST, 4.MIRAI, 5.Nagoya Univ.)

Keywords:Si-Ge, ball milling, thermoelectric property

In order to improve the figure of merit ZT, many strategies have been reported. For example, the 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 the B-doped Si-Ge-Au thin film and bulk sample possessed a 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 state 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 (TE) of bulk nanocrystalline samples were investigated as a function of temperature 300 – 1000 K, respectively.