Preparation And Properties For Fe Doped A-CN_x Films

Amorphous carbon-nitrogen film is a new type of functional material,with excellent optical,electrical,mechanical properties and good chemical stability.It has a wide range of application prospects in many fields.Iron as a deep level doping element can enrich and improve the optical properties of thin film materials.In this paper,Fe-doped a-CN_x films were prepared by plasma chemical vapor deposition.The effects of Fe doping concentration and process parameters on the morphology,structure and properties of the films were investigated.The main work and conclusions as follows:?1?With the increase of H₂ flow rate,the content of Fe in the film increases?1-12%?gradually,and the compactness of the film increases.The C-C bond in the film increases with the increase of Fe content,while the sp²C=N bond content decreases gradually,the sp³C-N bond bond also decreases.The incorporation of Fe makes the reflectivity of the a-CN_x film decrease in the 200-800 nm band range,and the optical band gap gradually decreases.The doping of Fe makes the emission center of the a-CN,film drift from 2.73 eV to 2.53 eV.The emission intensity of the film increases and the PL emission peak narrows.?2?With the increase of the preparation pressure,the proportion of sp²C=N bonds in the films increased?34.3-38.7%?,while the sp³C-N bonds decreased gradually?22.6-20.8%?,resulted in the decrease of the density of the films.The reflectance of the thin film decreases,red shift occurs in the absorption band edge,the optical bandgap decreases,the intensity of the PL spectrum increases,and the emission band red shifts,narrowing?0.2-0.15 eV?.As the substrate temperature increases,the proportion of C-C bonds increased gradually?30-33.4%?,the sp² hybrid phase structure inside the film decreased?34.8-27.8%?,and the sp³ hybrid phase structure increased?25.2-29.2%?,the hardness increased,the film gradually become dense.The reflectivity of the film decreases and the absorbance increases gradually in the 200-800 nm band range,the optical bandgap of the film increases gradually.The ratio of sp²/sp³ decreases,PL luminescence center of the film occur a blue shift,and the intensity enhances.As the N2 flow rate increases,the proportion of C-C bond bonds decreases?33.4-25,3%?gradually,sp²C=N bond content increases?27.8-34.8%?,and the film becomes loose gradually,the reflectivity increases in 400-800 nm band range,the optical bandgap decreases gradually,the PL luminescence center occur a red shifts,and the intensity decreases.