Figure 6

(a) Schematic illustration of anti-counterfeiting sticker by SMCF. (b) Photographs of SMCF in bending test. (c) Reflectance contour map of SMCF versus wavelength and bending cycle. The thickness and diameter of a-Si and Si NWA are 10 and 150 nm, respectively. The white lines indicate the resonant wavelengths of the SMCF. The bending radius is ~1 mm. (d) Photographs of SMCF as anti-counterfeiting sticker. Due to the angle sensitivity of Si NWA, the overall color of SMCF is varied according to the viewing angle. The scale bar is 5 mm.