Carrier transport and electroluminescence efficiency of erbium-doped silicon nanocrystal superlattices

摘要

A detailed study of transport phenomena and electroluminescence of erbium-doped silicon-rich oxide/silicon oxide superlattices is presented. Extended states conduction is thermally activated from Poole-Frenkel traps located at silicon nanocrystals or its interface. These traps provide bulk limited conduction at low and medium electric fields. In contrast, under high electric fields, conduction is governed by trap-assisted tunneling of electrons from the electrode to the active layer conduction band. Superlattice electroluminescence efficiency at 1.5 μm and injected electron energy distribution in the conduction band are evaluated and compared to a silicon dioxide and a silicon-rich oxide single layer. This work sheds light on the implementation of alternative electroluminescent device architectures with strong emphasis in the hot electron engineering.