Impedance Spectroscopy Analysis of Structural Defects in Sputtered ZnO FilmsShow others and affiliations
2020 (English)In: ChemElectroChem, E-ISSN 2196-0216, Vol. 7, no 9, p. 2055-2064Article in journal (Refereed) Published
Abstract [en]
The degradation of sputtered columnar ZnO layers under DC polarization was studied by using electrochemical impedance spectroscopy and electron microscopy. It was found that the structure of the as-deposited ZnO film was dense at the nanoscale. An equivalent circuit model including de Levie impedance accounted for the localized propagation of microscale cracks towards the copper substrate. This generates a capacitance (CZnO) that represents the crack surface area in contact with the electrolyte. CZnO is small enough not to be obscured by the double layer capacitance at the top of the layers and increases with increasingly negative potential and time. These results were compared to nanoporous ZnO layers that behave differently and exhibit a large CZnO. The combination of in situ EIS analysis with the ex situ structural information provided by electron microscopy proved to be an efficient methodology to characterize very different microstructures of conductive coatings.
Place, publisher, year, edition, pages
Wiley-VCH Verlag , 2020. Vol. 7, no 9, p. 2055-2064
Keywords [en]
impedance spectroscopy, microstructure, sputtering, thin films, zinc oxide, Capacitance, Cracks, Electrochemical electrodes, Electrolytes, Electron microscopes, Electron microscopy, Equivalent circuits, II-VI semiconductors, Metallic films, Oxide films, Spectroscopy, Spectrum analysis, Conductive coatings, Copper substrates, Double-layer capacitance, Equivalent circuit model, Negative potential, Structural defect, Structural information, Electrochemical impedance spectroscopy
National Category
Natural Sciences
Identifiers
URN: urn:nbn:se:ri:diva-50110DOI: 10.1002/celc.202000087Scopus ID: 2-s2.0-85082965321OAI: oai:DiVA.org:ri-50110DiVA, id: diva2:1497181
Note
Funding details: Association Nationale de la Recherche et de la Technologie, ANRT; Funding details: Ministaire de l'Education Nationale, de l'Enseignement Superieur et de la Recherche, MESR; Funding details: European Commission, EC; Funding details: European Regional Development Fund, FEDER; Funding details: Association Nationale de la Recherche et de la Technologie, ANRT, 2016/0066; Funding text 1: The financial support by the Association Nationale de la Recherche et de la Technologie (ANRT, Paris, France, contract CIFRE n° 2016/0066) is gratefully acknowledged. This work was also supported by the European Union through the European Regional Development Fund (ERDF), the Ministry of Higher Education and Research, the Région Bretagne, the Conseil Général du Finistère and Brest Métropole Océane, through the CPER Project 2015–2020 MATECOM. The authors thank Luiz F. G. Morales and Christian Zaubitzer (ScopeM, ETH Zurich) for technical support with HAADF‐STEM experiments.
2020-11-042020-11-042023-05-25Bibliographically approved