Structural evolution of laser-irradiated ultrananocrystalline diamond/amorphous carbon composite films prepared by coaxial arc plasma

Ultrananocrystalline diamond/hydrogenated amorphous carbon films were synthesized by coaxial arc plasma deposition. The morphological and structural evolutions of the films driven by laser irradiation (ArF, 193 nm, 20 ns) are examined at different laser energies (0.4–1 J cm−2). Up on laser irradiation, the films revealed hydrogen effusions accompanied by the transformation of sp3 into sp2-hybridization carbon. However, the film irradiated at 0.8 J cm−2 exhibited higher sp3 fractions, which can be attributed to that: a specific value of laser energy density (0.8 J cm−2) can provide a suitable amount of heating that is enough to quench the film and increase the sp3 contents.