NITROGENATED AMORPHOUS-CARBON AS A SEMICONDUCTOR

At present, hydrogenated amorphous carbon (a-C:H) is a poor electronic material primarily due to the excessive density of defect states in t he band gap which act as trapping centres. The ability of nitrogen to improve the semiconducting properties of a-C:H is examined. A reductio n in the activation energy for electronic conduction in nitrogenated a -C:H (a-C:H:N) films and the approximately constant optical band gap w ith increasing N content suggest that N influences the bulk electronic properties of a-C:H. Electron spin resonance shows a reduction of the density of gap states in a-C:H:N with increasing N content. Electron energy loss spectroscopy shows the films to be predominantly sp(2) bon ded with band edge properties which change significantly as a function of the N content. The C:H:N contents of the films were determined by elastic recoil detection analysis and Rutherford backscattering.