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Lecture

WEB Lead-free piezoelectric devices

Thursday (24.09.2020)
15:55 - 16:10 Z: Special Symposia I
Part of:


Summary:

Potassium sodium niobate (KNN) is a ferroelectric material that has piezoelectric properties and has an application in energy harvesting. Under project ITN-ENHANCE, funded by the EU-Horizon 2020, we are developing KNN devices from solution phase techniques. The work on the optimization of the parameters and fabrication steps to fabricate the piezoelectric KNN cantilevers have been performed. The KNN cantilevers have been developed, and with electrodes, their piezoelectric and dielectric properties have been investigated. Moreover, their performance has also been measured and power output and figure of merits have been estimated.

The energy harvesting of a piezoelectric device increases with its materials thickness. It becomes crucial to deposit dense and thick films. We have been able to develop thick film devices which are thicker (2X) then the published literature value of the same technique. The piezoelectric properties of the material should be comparable with Lead Zirconate Titanate (PZT), which is conventionally used as a piezoelectric material because of relatively higher piezoelectric properties. The toxicity of PZT is a disadvantage, therefore we are trying to provide a lead-free alternative in the field of piezoelectric energy harvesters for their implementation in automobiles under the project ENHANCE.

 

Motivation:

Phase pure KNN was synthesized. Through a process of optimization, thick & dense films of KNN have been deposited, The film's thickness was higher than those mentioned in literature for KNN using spin-coating technique. These piezoelectric KNN devices are fabricated to be used as energy harvesters for inducted to power sensors in automobiles. To harvest energy, thick-film piezoelectric devices prove to be better than their counterpart. To achieve the reproducibility and smoothness of the device morphology.

Moreover, the process from KNN synthesis up to the device fabrication and structural, ferroelectric and piezoelectric properties is highly repeatable. The dielectric and piezoelectric measurements are being made in the thickness mode electrode configuration where the material’s properties are being measured using the top and bottom electrodes.

Speaker:
Ph.D. Anjneya Verma
University of Cologne