Effect of Nitrogen Doping on the Photoluminescence of Amorphous Silicon Oxycarbide Films

The effect of nitrogen doping on the photoluminescence (PL) of amorphous SiC_xO_y films was investigated. An increase in the content of nitrogen in the films from 1.07% to 25.6% resulted in red, orange-yellow, white, and blue switching PL. Luminescence decay measurements showed an ultrafast decay dynamic with a lifetime of ~1 ns for all the nitrogen-doped SiC_xO_y films. Nitrogen doping could also widen the bandgap of SiC_xO_y films. The microstructure and the elemental compositions of the films were studied by obtaining their Raman spectra and their X-ray photoelectron spectroscopy, respectively. The PL characteristics combined with an analysis of the chemical bonds configurations present in the films suggested that the switching PL was attributed to the change in defect luminescent centers resulting from the chemical bond reconstruction as a function of nitrogen doping. Nitrogen doping provides an alternative route for designing and fabricating tunable and efficient SiC_xO_y-based luminescent films for the development of Si-based optoelectronic devices.