Electroluminescence at 1.54 microns in Er-doped Si nanocluster-based devices

The electroluminescence ~EL! properties of Er-doped Si nanoclusters ~NC! embedded in metal-oxide-semiconductor devices are investigated. Due to the presence of Si NC dispersed in the SiO2 matrix, an efficient carrier injection occurs and Er is excited, producing an intense 1.54 microns room temperature EL. The EL properties as a function of the current density, temperature, and time have been studied in detail. We have also estimated the excitation cross section for Er under electrical pumping, finding a value of about 1E-14 cm2. This value is two orders of magnitude higher than the effective excitation cross section of Er ions through Si NC under optical pumping. In fact, quantum efficiencies of about 1% are obtained at room temperature in these devices.