Physical limitations of the electroluminescence mechanism in Terbium-based light emitters: Matrix and layer thickness dependence

The physical limits of downscaling the SiO₂ thickness of rare earth implanted metal-oxynitride-oxide-semiconductor based light-emitters are explored by investigating the drop down of the electroluminescence power efficiency with decreasing SiO₂ thickness of Tb-implanted devices. It will be experimentally shown that there is a dark zone with an extension of about 20 nm behind the injecting interface in which the hot electrons have not yet gained enough kinetic energy in order to excite the Tb³⁺ luminescence centers. In addition, replacing the host matrix SiO₂ by SiON results in a decrease of power efficiency by two orders of magnitude which is consistent with experimental data about the hot energy distribution in these media.