Electroluminescence at 1.54 μm 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 ${\mathrm{SiO}}_2$ matrix, an efficient carrier injection occurs and Er is excited, producing an intense 1.54 μm 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 ${\text{∼1×10}}^{\text{−14}}\hspace{0.17em}{\mathrm{cm}}^2.$ 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 ∼1% are obtained at room temperature in these devices.