Electrical characteristics and temperature effects of electroluminescing silicon nanocrystals

The white electroluminescence (EL) demonstrated from Si nanocrystals in a wider bandgap amorphous oxide matrix based structure has exciting opportunities in electroptic applications as well as novel LEDs. In this report, we review the electroluminescent properties of the devices for rapid thermally annealed samples at anneal temperatures ranging from 875 °C to 1025 °C. Depending upon the anneal conditions the EL spectra has shown two distinct spectral features, a strong emission peak at 380 nm with a width of 50 nm, and a broader features centered above 800 nm,. Further, the I-V characteristics and corresponding EL spectra have been measured for sample temperatures ranging from 317 K to 240 K. In addition, Raman scattering estimated the mean particle sizes of the Si nanocrystals of 6.5 nm and 8 nm as well as provide insight to the nature of the amorphous matrix. The novel light emission from our devices demonstrates an exciting opportunity for Si nanocrystal (and nanocrystals in general) technology in a wide variety of applications.