Dimension 3000 nanoscope iiia

We used a digital microscope (VHX-5000; Keyence Co. Ltd., Japan) for the optical microscope observations. The SEM images were obtained with a scanning electron microscope with a field-emission gun (JSM-7000 F or -7500 F; JEOL Ltd.). The samples for cross-sectional SEM observation were prepared by an ion slicer (IB-09060CIS; JEOL Ltd.), keeping the sample temperature at −150 °C. Electrical properties of the printed silver patterns were measured by four-terminal measurements using a semiconductor parametric analyser (E5270A; Agilent Technologies Co. Ltd., USA). The thickness profile was estimated by using a stylus profiler (Alpha-Step D-500; KLA-Tencor Co. Ltd., USA) or by a scanning probe microscope (Dimension 3000 Nanoscope IIIa; Bruker Co., Ltd.). Raman measurements were carried out using a confocal Raman microscope (inVia, Renishaw Co. Ltd., UK). The adhesion measurements were carried out using a pull-off adhesion tester (PosiTest AT-A; DeFelsko Co., USA), conformable to ISO 4624.

Contact angle measurements were conducted with a contact angle and surface tension analyser (FTA188; First Ten Angstroms, Inc., USA). Atomic force microscope images were obtained with a scanning probe microscope (Dimension 3000 Nanoscope IIIa; Bruker Co., Ltd., USA). XPS measurements were carried out using an XPS apparatus (ULVAC-PHI 5000, ULVAC Inc., Japan) with monochromatic Al K_α radiation (1,486.6 eV, 15 kV). Because the Cytop layer is highly insulating and easily charged up by an incident beam, the films were slightly coated by vacuum-evaporated Ag to cover the partially polymer surface by island-shaped Ag. All the measurements were conducted with a neutralizer, and the offset shift was corrected by the reference signal of Ag 3d_5/2 (=368.3 eV). ESR measurements were carried out using an X-band ESR apparatus (JES-FA200, JEOL Ltd., Japan). A thick Cytop film with a thickness of ∼25 μm was fabricated by repeated (eight times) spin coating on a silicon wafer, and was peeled off from the wafer. The free-standing film was used in the ESR measurement. For this purpose, we used another Cytop (CTX-809SP2, Asahi Glass Co., Ltd.), which enables the facile peeling of Cytop film from the wafer. We could not detect any ESR signal from the unirradiated polymer film.