White electroluminescence from C- and Si-rich thin silicon oxides

White electroluminescence from carbon- and silicon-rich silicon oxide layers is reported. The films were fabricated by Si and C ion implantation at low energy in 40 nm thick SiO2, followed by annealing at 1100 degrees C. Structural and optical studies allow assigning the electroluminescence to Si nanocrystals for the red part of the spectrum, and to C-related centers for the blue and green components. The external efficiency has been estimated to 10(-4)%. Electrical characteristics show a Fowler-Nordheim behavior for voltages above 25 V, corresponding to the onset of electroluminescence. This suggests that light emission is related to the impact ionization of radiative centers. (c) 2006 American Institute of Physics.