Structural and bonding properties of carbon nitride films synthesized by low energy nitrogen-ion-beam-assisted pulsed laser deposition with different laser fluences

Abstract

Carbon nitride films were deposited by pulsed Nd:yttrium–aluminum–garnet laser ablation of graphite with assistance of low energy nitrogen-ion-beam bombardment. The nitrogen to carbon (N/C) atomic ratio, surface morphology, bonding state, and microstructure of the deposited carbon nitride films were characterized by x-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, micro-Raman spectroscopy, atomic force microscopy (AFM), and x-ray diffraction. The influence of laser fluence on the synthesis of carbon nitride films was investigated. The N/C atomic ratio of the carbon nitride films can reach the maximum at the highest laser fluence. XPS and FTIR analyses indicated that the bonding state between the carbon and nitrogen in the deposited films was significantly influenced by the laser fluence during deposition. The carbon–nitrogen bonding of C–N and C=N were observed in the films. In addition, α and β ${\mathrm{C}}_{\mathrm{3}}{\mathrm{N}}_{\mathrm{4}}$ phases were found to coexist in the carbon nitride films with relative low degree of ordering in the crystal lattice. AFM results indicated that the laser fluence also had a critical effect on the surface structure of the carbon nitride films.