Alloys and Compounds for Thermoelectric and Solar Cell Applications X: Session V
Sponsored by: TMS Structural Materials Division, TMS Functional Materials Division, TMS: Alloy Phases Committee
Program Organizers: Hsin-Jay Wu, National Chiao Tung University; Sinn-wen Chen, National Tsing Hua University; Franck Gascoin, CNRS Crismat Unicaen; Philippe Jund, Montpellier University; Yoshisato Kimura, Tokyo Institute of Technology; Takao Mori, National Institute For Materials Science; Alexandra Zevalkink, Michigan State University; Wan-Ting Chiu, Tokyo Institute of Technology; Pai-chun Wei, National Taiwan University
Wednesday 8:30 AM
March 2, 2022
Room: 303D
Location: Anaheim Convention Center
Session Chair: Wan-Ting Chiu, Tokyo Institute of Technology; Franck Gascoin, Cnrs Crismat Unicaen
8:30 AM Invited
Niobium Chalcogenides: Phases Stability and Transport Properties: Franck Gascoin1; Hugo Bouteiller1; David Berthebaud2; Sylvain Letonquesse2; Takao MORI3; Amélie Galodé4; Louise Goodwin4; 1Cnrs Crismat Unicaen; 2CNRS LINK; 3NIMS; 4University of Caen
Our previous studies of complex chromium chalcogenides (Ch) in the pseudo hollandite structure type have led to the discovery of new phases and interesting features that triggered our interest to explore further other transition metal chalcogenides. In this presentation, our latest results on light transistion metal selenides and tellurides will be shown. For instance, the niobium rich part of the binary phase diagram Nb - Ch will be discussed in detail and the presence of a eutectoide transformation debated. In this system, we will present our synthesis strategy and we will also show the transport properties of some niobium rich phases that might be find their interest at very high temperature.
8:50 AM
Rhombohedral Distortion Elicits High-performance GeTe Theremoelectrics: Bo-Chia Chen1; Kuang-Kuo Wang2; Hsin-Jay Wu1; 1National Yang Ming Chiao Tung University; 2National Sun Yat-sen University
Phase diagram engineering can probe the high zT zone for a multicomponent thermoelectric (TE) alloys by determining the maximal dopant solubility, which guides the inter-correlation between phase, microstructure, and thermal/electrical properties. GeTe-based alloys show intrinsically-high thermal conductivity , while the substitution of Ge by Bi substantially reduce the from 8 to 1.2 Wm-1K-1 at 323 K in the alloys of Ge1-xBixTe. As revealed by synchrotron XRD and TEM analysis, the co-existence of severe lattice distortion and high-density stacking faults brings down the . In addition to the enhanced phonon scattering, the carrier concentration of Ge1-xBixTe drops from 9.5 ×10^20 to 2×10^20 (cm-3). In one word, Ge0.9Bi0.1Te shows a low-lying and a high peak zT of 1.9 at 713 K, resulting from a high degree of rhombohedral distortion caused by the high-dose of Bi solubility.
9:10 AM Invited
Computational Understanding and Design of Carrier Lifetime in Solar Absorber Materials: Geoffroy Hautier1; 1Dartmouth
Current thin film solar cell technologies suffer from many drawbacks: low earth-abundance in Cu(In,Ga)(Se,S)2 (CIGS) or stability issues in organic-inorganic perovskite halides. My talk will focus first on recent work using high-throughput computational screening to identify new solar absorbers with exceptionally high carrier lifetime due to favorable defects. The second part of my talk will focus on the the eart-abundant CuZnSnS2 (CZTS) absorber. We will show using ab initio computations that Cu-Zn mixing in this material affects significantly lifetime through deep defect stabilization. I will conclude my talk outlining new avenues for future solar absorber research.
9:30 AM Concluding Comments