Intense blue pfaotoluminescence from Si-in-SiN_x thin film with high-density nanoparticles

摘要

Intense photoluminescence in blue was measured in as-deposited Si-in-SiN_x films prepared by plasma-enhanced chemical vapour deposition on cold substrates. The density of the silicon nanoparticles amounts to 1.4 X 10_(13) 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 deg C for two minutes roughly doubles the photoluminescence intensity, while the peak profile suffers only negligible change. In contrast, annealing at 1050 deg 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 percent 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-SiN_x films.