[21p-438-1~12] 9.4 Thermoelectric conversion

[21p-438-5] 【Highlighted Presentation】Self-tuning carrier concentration effect observed in Cu_2-δSe

〇Tsunehiro Takeuchi¹, Dogyun Byeon¹, Seongho Choi¹, Robert Sobota¹, Kevin Delime-Codrin¹, Masaharu Matsunami¹, Masahiro Adachi², Makoto Kiyama², Takashi Matsuura², Yoshiyuki Yamamoto² (1.Toyota Tech. Inst., 2.Sumitomo Elec.)

Keywords:unusual Seebeck effect, Colossal power factor, Huge dimensionless figure of merit

Cu_2-δSe is characterized by its possession of a structure phase transition around 340~400 K. We investigated its thermoelectric properties near the phase transition, and found a surprising phenomenon, that could be interpreted as a self-tuning carrier concentration effect on Seebeck coefficient. This unusual behavior of Seebeck coefficient will be presented together with behaviors of electrical resistivity and thermal conductivity.