Intense blue photoluminescence from Si-in-SiN_<i>x</i>thin film with high-density nanoparticles

Abstract

Intense photoluminescence in blue was measured in as-deposited Si-in-SiNx films prepared by plasma-enhanced chemical vapour deposition on cold substrates. The density of the silicon nanoparticles amounts to 1.4 × 1013 cm−2 as calculated from transmission electron microscope images, and the particle size can be well controlled under 2.6 nm. Rapid annealing at 500 °C for two minutes roughly doubles the photoluminescence intensity, while the peak profile suffers only negligible change. In contrast, annealing at 1050 °C results in a broadened spectrum red shifted by about 80 nm. External quantum efficiency for the photoluminescence was estimated to be well above 1.0% by comparing with GaN. This demonstrates that, with appropriate processing parameters, the low-temperature procedure is promising for obtaining applicable light emission from Si-in-SiNx films.