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Electrochemically driven degradation of PZT in humid ambient

Electrochemically driven degradation of PZT in humid ambient

Category
Journal publication
Abstract
Ambient humidity significantly accelerates degradation of PZT films in microelectromechanical systems; the cause of such degradation is under debate. Here it is shown that the primary driving force for PZT degrading in humid conditions is coupled to the electrochemical activity of the system towards water electrolysis. A degradation model is proposed based on electrochemically driven processes occurring at potentials from about 1.5 V, which corresponds to the overpotential for the electrolysis reaction. Electrolysis of liquid or gaseous H2O involves evolution of oxygen and hydrogen gas, causing cracking of the PZT film and delamination of the electrodes. The magnitude of the electrothermal breakdown events was significantly larger in humid compared to dry conditions. Overall, these factors result in failure up to three orders of magnitude of time earlier than for operation under dry conditions. Thus, it is imperative, in order to improve the resilience of thin film piezoelectric microelectromechanical systems in humid conditions, to protect the electrochemically active electrode components of the device.
Client
  • Norges forskningsråd / NBRIX: Prosjektnummer: 247781
  • Norges forskningsråd / NBRIX: PROSJEKTNUMMER: 247781
Language
English
Author(s)
  • Dahl-Hansen Runar Plunnecke
  • Akkopru-Akgun Betul
  • Polfus Jonathan M.
  • Vøllestad Einar
  • Denis Lyndsey
  • Coleman Kathleen
  • Tyholdt Frode
  • Trolier-Mckinstry Susan E
  • Tybell Per Thomas Martin
Affiliation
  • Norwegian University of Science and Technology
  • SINTEF Industry / Sustainable Energy Technology
  • SINTEF Digital / Microsystems and Nanotechnology
Year
2019
Published in
Advanced Functional Materials
ISSN
1616-301X
Publisher
Wiley - VCH Verlag GmbH