Interfacial characteristics of polyethylene terephthalate-based piezoelectric multi-layer films

• Published in: Thin solid films Vol. 531; pp. 284 - 293
• Main Authors: Liu, Z.H., Pan, C.T., Chen, Y.C., Liang, P.H.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.03.2013; Elsevier
• Subjects: Adhesion; Aluminum; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Dielectric, piezoelectric, ferroelectric and antiferroelectric materials; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Indium tin oxide; Materials science; Mechanical and acoustical properties; Methods of deposition of films and coatings; film growth and epitaxy; Multilayer; Multilayers; Nano-indentation; Nanostructure; Physical properties of thin films, nonelectronic; Physics; Piezoelectricity; Polyethylene terephthalate; Polyethylene terephthalates; Scratch test; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Zinc oxide; Multilayer; Indium tin oxide; Nano-indentation; Scratch test; Polyethylene terephthalate; Zinc oxide; Adhesion; Ethylene terephthalate polymer; Scratching test; Polyethylenes; Piezoelectric properties; Plastic deformation; Chip; Terephthalates; Thin films; Multilayers; Tin oxide; Physical vapor deposition; Delamination; Flexible structures; Scanning electron microscopy; Transducers; Nanoindentation; Mechanical properties; Preferred orientation; Indium oxide; Interfaces; Radius of curvature; Composite materials; Piezoelectric materials; Mechanical stress; Tribology
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2013.01.070

The study examines the deformation between interfaces and the adhesion mechanism of multi-layer flexible electronic composites. Indium tin oxide (ITO), aluminum (Al), and zinc oxide (ZnO) were deposited on a polyethylene terephthalate (PET) substrate using radio frequency magnetron sputtering at room temperature to form flexible structures (e.g., ITO/PET, Al/PET, ZnO/ITO/PET, and ZnO/Al/PET) for piezoelectric transducers. ITO and Al films are used as the conductive layers. A ZnO thin film shows a high (002) c-axis preferred orientation at 2θ=34.45° and excellent piezoelectric properties. Nanoscratching and nano-indention testing were conducted to analyze the adhesion following periodic mechanical stress. Additionally, two Berkovich and conical probes with a curvature radius of 40nm and 10μm are examined for the scratching test. A 4-point probe is used to measure the conductive properties. The plastic deformation between the ductile Al film and PET substrate is observed using scanning electron microscopy to examine the chip formation on the ITO/PET. Delamination between the ZnO and Al/PET substrate was not observed. The result suggests that ZnO film has excellent adhesion with Al/PET compared to ITO/PET. ► Interfaces and adhesion mechanism of multi-layer flexible electronic composites ► Polyethylene terephthalate (PET) based flexible structures ► Nano-scratching and nano-indention tests were used to analyze adhesion. ► Using two various probes of Berkovich and conical ► Piezoelectric zinc oxide film has excellent adhesion with aluminum/PET.