X-ray photoelectron spectroscopy studies on the bonding properties of oxygenated amorphous carbon nitride thin films synthesized by pulsed laser deposition at different substrate temperatures

Oxygenated amorphous carbon nitride thin films (a-CNxOy) were deposited by pulsed laser deposition of camphoric carbon (CC) target at various substrate temperatures (ST). The influence of ST on the bonding properties of a-CNxOy films was investigated. The nitrogen to carbon (N/C) atomic ratio and oxygen to carbon (O/C) atomic ratio, bonding state and microstructure of the deposited a-CNxOy films were characterized by X-ray photoelectron spectroscopy (XPS) and been confirmed using standard measurement techniques. The bonding states between the C and N, and C and O in the deposited films are found significantly influenced by the ST during deposition process. The N/C and O/C atomic ratio of the a-CNxOy films reached the maximum value at 400 °C. The XPS C 1s shows the bonding state of a-CNxOy films changes from diamond-like tetrahedral (sp3) carbon and carbon (C–C) bonding to graphite-like trihedral (sp2) CC bonding with the increase of ST. While, the XPS N 1s shows the sp3 C–N bonds increases with higher rates compared with sp2 CN bonds up to 400 °C, after which it decreases with higher ST. The C–N bonding of C–N, CN and CN were observed in the deposited a-CNxOy films.