Cathodoluminescence of Cr-doped diamond-like carbon film by filtered cathodic vacuum arc plasma

Cr doped diamond-like carbon (DLC:Cr) film was synthesized in various flow rates of C2H2/Ar under a substrate voltage of −50 V at 500 °C by a filtered cathodic vacuum arc plasma. This work has found that the structure of the films was correlated to the flow rate of C2H2/Ar but the luminescence properties are similar. The cathodoluminescence spectra of DLC:Cr films obtained at 1.9-2.4 eV verifies that the luminescence from the films is in the visible region. The incorporation of Cr into the carbon network results in red emission shifted to 1.99 eV and the orange emission (2.03 eV) also appeared due to the transitions between chromium-related electron levels and σ* states. The peak at 2.10 eV may result from the defects of the structures in DLC:Cr films.

► The formation of the DLC:Cr films dependent on the flow rates of C2H2/Ar have been achieved in our FCVA plasma. ► The amorphous DLC:Cr have high sp2 content can be completely converted to nanocrystalline Cr3C2. ► The effect of doping with Cr is apparently to change the band structure of the DLC and its consequent cathodoluminescence property.