Achieving synergistic performance through highly compacted microcrystalline rods induced in Mo doped GeTe based compounds
Journal
Materials Today Physics
Journal Volume
22
Date Issued
2022
Author(s)
Abstract
Among the lead-free thermoelectric material, germanium telluride (GeTe) has been extensively investigated due to its high thermoelectric performance (ZT) in mid-temperature; however, high p-type carrier density (∼1021 cm−3) hinder its suitability for higher ZT. To enhance the thermoelectric performance of the environmentally favorable GeTe, we explored the Mo doping significantly optimizes the carrier concentration along with uniquely unveiled microcrystalline rods accompanying compact grain boundaries, high-density planar defects, and point defects effectuating all-frequency phonon scattering yields to lower down the thermal conductivity. Furthermore, Sb/Bi co-doping with Mo at the Ge sites predominantly reduces the carrier concentration and thermal conductivity to attain a higher ZT. The co-doping of Bi manifested a more prominent role in achieving the highest ZT of ∼2.3 at 673 K for the sample composition with Ge0.89Mo0·01Bi0.1Te. This study demonstrates an exciting hidden aspect of microstructural modification by forming highly dense microcrystalline rods through Mo doping to achieve high performance in the GeTe system. © 2021 Elsevier Ltd
Subjects
Carrier concentration optimization;Figure of merit;GeTe;Microcrystalline rods;Thermal conductivity
SDGs
Other Subjects
Germanium compounds;Grain boundaries;Molybdenum compounds;Point defects;Tellurium compounds;Thermal conductivity;Thermoelectricity;Carrier concentration optimization;Co-doping;Figure of merit;Germanium telluride;Microcrystalline rod;Microcrystallines;Mo-doping;Optimisations;Performance;Thermoelectric performance;Carrier concentration
Type
journal article