Structural and electrochemical properties of amorphous carbon nitride films deposited by femtosecond pulsed laser ablation

International audienceAmorphous carbon nitride (a-C:N) material has attracted much attention in research and development [1]. Recently, it has become a more promising electrode material than conventional carbon based electrodes in electrochemical and biosensor applications [2]. Nitrogen containing amorphous carbon (a-C:N) thin films have been deposited by femtosecond pulsed laser deposition (fs-PLD) coupled with plasma assistance. During the deposition process, various nitrogen pressures (0-50 Pa) and Direct Current (DC: 0-400 V) biases were used in order to introduce a wide range of nitrogen content into the films. The ablated carbon plume expansion has been investigated by ICCD gated Optical emission spectroscopy (OES) and direct 2D spectral imaging under N2 gas and DC plasma assistance. The structure and chemical composition of the films have been studied by using Multi-wavelength (MW) Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Electron energy loss spectroscopy (EELS) and Reflection electron energy loss spectroscopy (REELS). While deposition, the intensity of the reactive activated species in the plasma plume is increased with DC biased assistance as compared to the bare N2 atmosphere, which was confirmed by optical emission spectroscopy, those deposition conditions induce an overall increase of nitrogen content in films up to 28 at.% and the formation of sp2 rich graphitic-like structures. Electrochemical properties have been investigated by cyclic voltammetry (CV) measurements to choose innovative electrode material for sensor applications. The a-C:N films show better electron transfer kinetics and excellent reproducibility than the pure a-C films. This study reveals the a-C:N films could be a promising electrode material in electrochemical detection of traces of pollutants and bio pathogen molecules. It is expected to be an alternative to BDD electrode in the near futur