Iron, nitrogen and silicon doped diamond like carbon (DLC) thin films: A comparative study

• Fe, N and Si doped DLC films deposited by dip, PLD and PECVD methods respectively
• DLC:Fe thin films have higher hardness/Young's modulus than DLC:N(:Si) thin films.
• sp3 and sp2 contents are estimated from C K-edge XANES and VB-PES measurements.

The X-ray absorption near edge structure (XANES), X-ray photoelectron spectroscopy (XPS), valence band photoemission (VB-PES) and Raman spectroscopy results show that the incorporation of nitrogen in pulsed laser deposited diamond like carbon (DLC) thin films, reverts the sp3 network to sp2 as evidenced by an increase of the sp2 cluster and ID/IG ratio in C K-edge XANES and Raman spectra respectively which reduces the hardness/Young's modulus into the film network. Si-doped DLC film deposited in a plasma enhanced chemical vapour deposition process reduces the sp2 cluster and ID/IG ratio that causes the decrease of hardness/Young's modulus of the film structure. The Fe-doped DLC films deposited by dip coating technique increase the hardness/Young's modulus with an increase of sp3-content in DLC film structure.