Electroluminescence of silicon nanoclusters excited by tunneling carrier injection

A simple model for the electroluminescence of a network of silicon nanoclusters (Si-NCs) embedded in a wide band gap material is presented. The model assumed that electrons and holes travel across the network through tunneling mechanisms and confine in excitonic states. Recombination of electron-hole pairs gives rise to the light emission. It shows that differences between the tunneling rates into neighboring Si-NCs of electrons and holes make the recombination events more frequent in a region close to the positive electrode of the device. Results further demonstrated that both total recombination rate and dissipated power increase with the spatial density of the nanoclusters in the matrix, but that a technological optimum range of density exists.