Figure 6
(a) Changes in the film sheet resistance (final compressive Rs/initial flat Rs) under applied compressive stress up to 23 GPa in 100 nm thick ITO film and DGPN on a flexible PET substrate. Samples were rolled up in different curvature using cylindrical tubes (top left inset) to apply fixed compressing stress on the attached films. Photograph of the wrinkled conducting graphene-polymer nanocomposite film on PET substrate (top right inset). Bottom inset representing the schematic illustration of the flat and compressed thin film on a flexible substrate. (b) Optical micrograph of the compressed 100 nm ITO film on PET substrate (under 23 GPa compressive stress) showing clear mechanical crack lines. (c,d) AFM micrograph of the same sample (b) showing ITO crack height profile (c) compare to the flat ITO morphology on PET substrate without stress (d). (e) AFM micrograph of the graphene-polymer nanocomposite film under 24 GPa applied stress on PET substrate. (f) Transmittance spectra comparison between compressed (24 GPa stress) and flat (without applied stress) graphene-polymer nanocomposite on PET substrate.
