Field effect luminescence from Si nanocrystals obtained by plasma-enhanced chemical vapor deposition

Field effect induced luminescence has been achieved by alternate tunnel injection of electrons and holes into Si nanocrystals. The emitting device is a metal-oxide-semiconductor structure with a semitransparent polycrystalline Si contact ∼250 nm thick and a silicon-rich silicon oxide layer of about 40 nm deposited on a p-type Si substrate by plasma-enhanced chemical vapor deposition. The electroluminescence is optimized for a Si excess of 17% and annealing at 1250 °C for 1 h in nitrogen-rich atmosphere. The pulsed emission presents typical decay times of ∼5 μs and external quantum efficiencies of ∼0.03%.