On the high-temperature degradation mechanism of ZnO-based thermoelectrics
authors Arias-Serrano, BI; Mikhalev, SM; Ferro, MC; Tobaldi, DM; Frade, JR; Kovalevsky, AV
nationality International
journal JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
author keywords Zinc oxide; Thermoelectrics; Degradation mechanism; Microstructural evolution; Electrical properties
keywords AL-DOPED ZNO; THERMAL-CONDUCTIVITY; OXIDE; STABILITY; CERAMICS; SOLUBILITY
abstract The stability and reproducibility of the electric properties in n-type doped ZnO represent known bottlenecks towards potential thermoelectric applications. The degradation is promoted by the vanishing of the electronic defects on oxidation and irreversible exsolution of the phase impurities. This work proposes a microstructural mechanism showing that these processes take place mainly in the pores and highlighting the necessity for high densification of ZnO-based thermoelectrics to ensure more stable operation. The electrical performance was monitored at various temperatures, followed by a detailed microstructural analysis. The evolution of the electrical conductivity and Seebeck coefficient confirm that the degradation is related to a gradual decrease in the charge carrier concentration rather than to the effects suppressing their mobility. The results suggest that the donor exsolution may promote an increase or decrease of the power factor, guided by the self-optimization of the charge carrier concentration.
publisher ELSEVIER SCI LTD
issn 0955-2219
isbn 1873-619X
year published 2021
volume 41
issue 2
beginning page 1730
ending page 1734
digital object identifier (doi) 10.1016/j.jeurceramsoc.2020.09.035
web of science category 5
subject category Materials Science, Ceramics
unique article identifier WOS:000599811000004
  ciceco authors
  impact metrics
journal analysis (jcr 2019):
journal impact factor 4.495
5 year journal impact factor 4.283
category normalized journal impact factor percentile 98.214
dimensions (citation analysis):
altmetrics (social interaction):



 


Apoio

1suponsers_list_ciceco.jpg