Thermoelectric Materials: Compositional Fluctuations Locked by Athermal Transformation Yielding High Thermoelectric Performance in GeTe (Adv. Mater. 1/2021)

Abstract

In article number 2005612, Pai‐Chun Wei, Hsin‐Jay Wu, and co‐workers leverage the interplay between the spinodal decomposition and athermal phase transition in GeTe‐based thermoelectric materials. The exquisite microstructure, featured by strong composition fluctuations and the coexistence of rhombohedral‐ and cubic‐GeTe, yield high zT values of >2.6. This work provides a new thermodynamic route to developing higher‐performance thermoelectric materials in general.

Enhancing the thermoelectric performance of GeTe through Sb doping and nanocompositing with SiC for reduced thermal conductivity

“…The maximum zT value for pristine GeTe is approximately 0.9, which is consistent with previous reports. 43–45 At 800 K, the Ge 0.92 Sb 0.08 Te + 0.2 wt% SiC sample achieves a maximum zT value of 1.82, representing a 1.8-fold increase compared to that of pristine GeTe. This indicates a successful improvement in the thermoelectric properties of the material through the synergistic employment of a multifaceted thermal conductivity reduction scheme.…”

Influence of Ge Lone Pairs on the Elasticity and Thermal Conductivity of GeSe–AgBiSe2 Alloys

“…Chalcogenide-based IV–VI compounds, particularly cubic PbTe, − rhombohedral GeTe, − and orthorhombic SnSe, , show excellent TE efficiency ( zT ∼ 2) in the mid-temperature range (550–800 K). For instance, polycrystalline SnSe achieved an average TE figure of merit zT of 2 in the temperature range 400–783 K .…”