Nitrogen doped hydrogenated amorphous diamond-like carbon thin films have been synthesized by radio frequency (rf) plasma-enhanced chemical vapor deposition (PECVD) using CH4 as the source of carbon and with different N2 flow rates (N2/CH4 gas ratios between 0 and 3), at 300 K. The dependence of optical and structural properties/modifications on the nitrogen incorporation was investigated using Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), UV-visible spectroscopy and electron spin resonance (ESR) measurements. It was found that the configuration of nitrogen atoms incorporated into an amorphous carbon network gradually changed from nitrogen atoms surrounded by three (σ bonding) to two (Π bonding) neighbor carbons with increasing nitrogen flow rate. The Tauc optical gap was reduced from 2.6 to 2.0 eV with increasing nitrogen flow rate. The ESR spin density and the peak-to-peak linewidth increased drastically with increasing nitrogen flow rate. Significant structural modifications were observed above a gas ratio N2/CH4 of 1.
- Diamond-like carbon
- n-type doping
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Mechanical Engineering
- Materials Chemistry
- Electrical and Electronic Engineering