Speaker: Dr. Zhifeng Ren (University of Houston)

Host: Research Fellow Yang-Yuan Chen (Institute of Physics, Academia Sinica)

Time: 10:00, Friday, January 10, 2020

Place: 5F, 1st Meeting Room, Institute of Physics, Academia Sinica

Abstract: Bi2Te3-based p-type Bi0.5Sb1.5Te3 and n-type Bi2Te2.7Se3 have been the only materials for thermoelectric cooling for decades. Even though the progress on advancing the thermoelectric figure-of-merit (ZT) has been significant especially the materials with peak ZT at high temperatures, materials with high enough ZT around room temperature are very rare. Up to now, in addition to Bi2Te3-based ones, the only reported is p-type MgAgSb with ZT of ~0.8 at room temperature. There is rare report on any n-type material exhibiting ZT similar to that of the n-type Bi2Te2.7Se3. In this talk, Dr.Ren will present a new n-type material that has a ZT of ~0.7 at room temperature, which is comparable to that of n-type Bi2Te2.7Se3. The cooling performance of a unicouple consisting of the new n-type material and the p-type Bi0.5Sb1.5Te3 is also in par with the commercial legs consisting of the p-type Bi0.5Sb1.5Te3 and n-type Bi2Te2.7Se3. In addition, Dr.Ren will also discuss the recent progress on realizing thermal conductivity above 1200 W m-1 K-1 at room temperature in Boron Arsenide single crystals.