Baraki, Raschid ; Novak, Nikola ; Hofstätter, Michael ; Supancic, Peter ; Rödel, Jürgen ; Frömling, Till (2015)
Varistor piezotronics: Mechanically tuned conductivity in varistors.
In: Journal of Applied Physics, 118 (8)
doi: 10.1063/1.4929360
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
The piezoelectric effect of ZnO has been investigated recently with the goal to modify metal/semiconductor Schottky-barriers and p-n-junctions by application of mechanical stress. This research area called “piezotronics” is so far focused on nano structured ZnO wires. At the same time, ZnO varistor materials are already widely utilized and may benefit from a piezotronic approach. In this instance, the grain boundary potential barriers in the ceramic can be tuned by mechanical stress. Polycrystalline varistors exhibit huge changes of resistivity upon applied electrical and mechanical fields and therefore offer descriptive model systems to study the piezotronic effect. If the influence of temperature is contemplated, our current mechanistic understanding can be interrogated and corroborated. In this paper, we present a physical model based on parallel conducting pathways. This affords qualitative and semi-quantitative rationalization of temperature dependent electrical properties. The investigations demonstrate that narrow conductive pathways contribute to the overall current, which becomes increasingly conductive with application of mechanical stress due to lowering of the barrier height. Rising temperature increases the thermionic current through the rest of the material with higher average potential barriers, which are hardly affected by the piezoelectric effect. Hence, relative changes in resistance due to application of stress are higher at low temperature.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2015 |
| Autor(en): | Baraki, Raschid ; Novak, Nikola ; Hofstätter, Michael ; Supancic, Peter ; Rödel, Jürgen ; Frömling, Till |
| Art des Eintrags: | Bibliographie |
| Titel: | Varistor piezotronics: Mechanically tuned conductivity in varistors |
| Sprache: | Englisch |
| Publikationsjahr: | 28 August 2015 |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Journal of Applied Physics |
| Jahrgang/Volume einer Zeitschrift: | 118 |
| (Heft-)Nummer: | 8 |
| DOI: | 10.1063/1.4929360 |
| Kurzbeschreibung (Abstract): | The piezoelectric effect of ZnO has been investigated recently with the goal to modify metal/semiconductor Schottky-barriers and p-n-junctions by application of mechanical stress. This research area called “piezotronics” is so far focused on nano structured ZnO wires. At the same time, ZnO varistor materials are already widely utilized and may benefit from a piezotronic approach. In this instance, the grain boundary potential barriers in the ceramic can be tuned by mechanical stress. Polycrystalline varistors exhibit huge changes of resistivity upon applied electrical and mechanical fields and therefore offer descriptive model systems to study the piezotronic effect. If the influence of temperature is contemplated, our current mechanistic understanding can be interrogated and corroborated. In this paper, we present a physical model based on parallel conducting pathways. This affords qualitative and semi-quantitative rationalization of temperature dependent electrical properties. The investigations demonstrate that narrow conductive pathways contribute to the overall current, which becomes increasingly conductive with application of mechanical stress due to lowering of the barrier height. Rising temperature increases the thermionic current through the rest of the material with higher average potential barriers, which are hardly affected by the piezoelectric effect. Hence, relative changes in resistance due to application of stress are higher at low temperature. |
| Freie Schlagworte: | Grain boundaries; Varistors; Piezoelectric effects; Schottky barriers; Current density |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Nichtmetallisch-Anorganische Werkstoffe 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften |
| Hinterlegungsdatum: | 14 Sep 2015 12:31 |
| Letzte Änderung: | 14 Sep 2015 12:31 |
| PPN: | |
| Sponsoren: | This work was financed by the Deutsche Forschungsgemeinschaft (DFG) under the Project No. RO954/23 |
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