Open AccessSuperior performance and high service stability for GeTe-based thermoelectric compounds
Author(s) -
Tong Xing,
Qingfeng Song,
Pengfei Qiu,
Qihao Zhang,
Xugui Xia,
Jincheng Liao,
Ruiheng Liu,
Hui Huang,
Jiong Yang,
Shengqiang Bai,
Dudi Ren,
Xun Shi,
Lidong Chen
Publication year - 2019
Publication title -
national science review/national science review
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.433
H-Index - 54
eISSN - 2095-5138
pISSN - 2053-714X
DOI - 10.1093/nsr/nwz052
Subject(s) - thermoelectric effect , materials science , doping , phase transition , seebeck coefficient , thermal stability , thermoelectric materials , thermal expansion , thermal conductivity , condensed matter physics , thermodynamics , phase (matter) , atmospheric temperature range , analytical chemistry (journal) , nanotechnology , optoelectronics , chemical engineering , metallurgy , composite material , chemistry , physics , organic chemistry , chromatography , engineering
GeTe-based compounds have been intensively studied recently due to their superior thermoelectric performance, but their real applications are still limited so far due to the drastic volume variation that occurs during the rhombohedral-cubic phase transition, which may break the material or the material/electrode interface during service. Here, superior performance and high service stability for GeTe-based thermoelectric compounds are achieved by co-doping Mg and Sb into GeTe. The linear coefficient of thermal expansion before phase transition is greatly improved to match that after phase transition, yielding smooth volume variation around the phase transition temperature. Likewise, co-doping (Mg, Sb) in GeTe successfully tunes the carrier concentration to the optimal range and effectively suppresses the lattice thermal conductivity. A peak zT of 1.84 at 800 K and an average zT of 1.2 in 300-800 K have been achieved in Ge 0.85 Mg 0.05 Sb 0.1 Te. Finally, a Ni/Ti/Ge 0.85 Mg 0.05 Sb 0.1 Te thermoelectric uni-leg is fabricated and tested, showing quite good service stability even after 450 thermal cycles between 473 K and 800 K. This study will accelerate the application of GeTe-based compounds for power generation in the mid-temperature range.