Room-temperature visible luminescence from silicon nanocrystals in silicon implanted SiO2 layers

Abstract

We report the observation of visible‐light emission at room temperature from high fluence (0.3–3×10¹⁷ cm⁻²) Si⁺ implanted thermal SiO₂ layers grown on silicon substrates. Significant blue‐light emission and an intense broad luminescent band with a peak beyond 750 nm are observed after annealing at high temperature (T≥1000 °C). The red‐light emission, present only in the highest fluence implant, is attributed to the luminescence emitted from silicon nanocrystals produced by silicon precipitation. The presence of silicon nanocrystals is confirmed by transmission electron microscopy. Significant blue‐light emission is visible after thermal annealing in the 1×10¹⁷ cm⁻² fluence implant. The peak position shifts from 490 to 540 nm by increasing the annealing cycles temperature.