Characteristics of phosphorus-doped diamond-like carbon films synthesized by plasma immersion ion implantation and deposition (PIII and D)

Plasma immersion ion implantation and deposition (PIII and D) is an effective approach to synthesize high quality thin films for different industrial applications. This dual implantation and deposition process can produce a graded layer that mitigates delamination and poor adhesion. In this work, phosphorus-doped diamond-like carbon (DLC) films were synthesized by PIII and D. Thin DLC films with various phosphorus concentrations were produced by using different experimental parameters. The chemical composition was determined by X-ray photoelectron spectroscopy (XPS) and electron energy loss spectroscopy (EELS). Micrographs obtained by cross-sectional transmission electron microscopy (X-TEM) reveal good adhesion between the films and substrates. The biocompatibility was evaluated using platelet adhesive tests. The results show that the sample doped with an optimal amount of phosphorus exhibits less platelet adhesive and activation, and the overall results are better than that observed on low-temperature isotropic pyrolytic carbon (LTIC). Phosphorus-doped DLC films thus have potential applications in blood contacting medical devices.