Study of the electroluminescence at 1.5 μm of SiOx :Er layers made by reactive magnetron sputtering

We have studied the current transport and electro-luminescence mechanisms of four layers of Si oxide co-doped with Si nanoclusters and erbium ions. Electrical measurements have identified different conduction mechanisms in separate high-field and low-field regimes, including Poole-Frenkel hopping. In particular, hopping through the Si-ncl is evidenced by C-V measurements. We have also observed an important contribution of defects from the oxide in the conduction, and no evidence of Fowler-Nordheim tunnelling. The results suggest that the electroluminescence from erbium ions in silicon-rich silicon dioxide is generated by electrons transported through the active layer by hopping from localised states, which we associate with silicon nanoclusters.