Diamond-like carbon films deposited at room temperature on flexible plastics substrates for antireflection coating

In this present work, diamond-like carbon (DLC) films were coated onto polycarbonate (PC) substrates as a protective layer at room temperature by radio frequency (rf) magnetron sputtering technique. The I_D=I_G ratio, roughness (R_a), and contact angle of amorphous DLC films could be controlled by regulating deposition power. The DLC films deposited at 150W with a good hardness of as high as 13.74 GPa were realized with a surface roughness and contact angle of 0.63nm (R_a) and 103°, respectively. Ultraviolet/visible (UV/vis) spectrophotometry of single-layer DLC films showed a high transmissive ability (>80%) in the visible wavelengths. No cracks occurred on the surface of DLC films after the flexibility test 500 times at a frequency of 8.6 min^-1. This confirms the excellent adhesion of DLC films on PC plastic substrates with potential applications in flexible optoelectronic devices.