Influence of the oxygen content in obtaining tunable and strong photoluminescence from low-temperature grown silicon oxycarbide films

• Luminescent a-SiCxOy films were prepared at a low temperature of 150 °C.
• A-SiCxOy films can be tuned to emit light in different colors.
• The intense light emissions can be observed with the naked eye in a bright room.
• The change in PL characteristics is ascribed to the variation of oxygen content.

Luminescent a-SiCxOy films were prepared at a low temperature of 150 °C by using very high frequency plasma enhanced chemical vapor deposition technique. The prepared a-SiCxOy films present remarkable photoluminescence with yellow to blue shifting emission when increasing the oxygen content from 29% to 44%. Interestingly, the light emissions in the visible region can be clearly observed with the naked eyes in a bright room. The structure and the chemical compositions of the films were further investigated by Raman spectroscopy and Fourier transform infrared absorption spectroscopy, respectively. Based on the PL results and the analyses of the bonding configurations of the films, the yellow emission is suggested from the SiC related defect luminescent centers, while the blue emission is associated with Si-related oxygen defect luminescent centers.