Role of ex-situ oxygen plasma treatments on the mechanical and optical properties of diamond-like carbon thin films

Role of ex-situ oxygen plasma (OP) treatment on mechanical properties of diamond-like carbon (DLC) thin films is explored. The DLC film after this treatment shows superhardness behaviour, maximum hardness of 46.3 GPa and elastic modulus of 423.2 GPa are obtained when film grown at self bias of 100 V followed by 10 min OP treatment. Moreover, the colour of the coating is fed after OP treatment, leading it to a colourless coating with significantly enhanced transmittance and improved antiglare property. Such OP treated DLC films may find their applications as protective coatings on cutting tools, automobile parts, magnetic storage media and colourless coating in packaging, as the DLC films posses brown colour.

► Growth of DLC films have been done under varied self bias from 100 to 250 V.
► Post deposition oxygen plasma treatment (OPT) improves the mechanical properties of DLC thin films.
► Mechanical properties correlated with FTIR results.
► Based on mechanical performance a model has been prepared.
► DLC film followed by OPT has also been grown on large area glass substrate.