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

Abstract

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 40nm thick SiO2, followed by annealing at 1100°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 25V, corresponding to the onset of electroluminescence. This suggests that light emission is related to the impact ionization of radiative centers.