Effect of the laser power density on the properties and structures of the diamond-like carbon films deposited by pulsed laser ablation of graphite

Diamond-like carbon films were deposited by high-frequency and high-power pulsed XeCl excimer laser ablation of pyrolytic graphite targets in a high vacuum chamber at room temperature. The effects of the laser power density on the properties and tructures of the films were studied by setting the laser power density on the target at 10(8), 10(9) and 10(10) W/cm(2). The optical transparency and the optical band gap as well as the electron diffraction patterns and Raman spectra of the films were investigated. The results demonstrated that the structures of the films varied from amorphous to nanocrystalline diamond with the laser power density increasing from 10(8) to 10(10)W/cm(2)