Pulsed laser deposition of amorphous diamond-like carbon films with ArF (193 nm) excimer laser

We have deposited hydrogen-free diamond-like amorphous carbon films by ArF (193 nm) pulsed laser ablation of graphite. The deposition process is performed with a laser power density of only 5 × 10⁸W/cm²at room temperature without any auxiliary energy source incorporation. The resulting films possess remarkable physical, optical, and mechanical properties that are close to those of diamond and distinct from the graphite target used. The films have a mechanical hardness up to 38 GPa, an optical energy band gap of 2.6 eV, and excellent thermal stability. Analysis of electron energy loss spectroscopy reveals the domination of diamond-type tetrahedral bonding structure in the films with thesp³bond fraction over 95%. Compared with other reported results of pulsed-laser-deposited diamond-like carbon films, our experimental results confirm that the laser wavelength or photon energy plays a crucial role in controlling the properties of the pulsed-laser-deposited diamond-like carbon films.