The difference between the white and near-infrared electroluminescence of metal-oxide-semiconductor light-emitting diodes fabricated on 1,100 °C-annealed Si-rich SiOx/p-Si substrate with interfacial pyramidal Si dots (Si nano-pyramids)was characterized.
By changing the substrate temperature and induced coupled plasma power during the plasma enhanced chemical vapor deposition of Si-rich SiOx films, the effects of the growth conditions on the defect- and Si nano-pyramid-related carrier transport and Si nanocrystal-related
electroluminescence spectroscopy were also investigated. The annealed Si-rich SiOx/p-Si films grown at higher synthesized substrate temperate (350 °C)show the larger Si nano-pyramids precipitating near the Si/SiO2 interface. The indium tin oxide/Si-rich
SiOx/p-Si/Al metal-oxide-semiconductor light-emitting diodes with Si-rich SiOx films exhibit different white-light electroluminescence spectra at wavelengths from 400 to 650 nm. The Si nanocrystal-related electroluminescence spectra at 650–850
nm are confirmed, whereas the electroluminescence spectra are shorter wavelengths is attributed to oxygen related defects. These defects become an electron-preferred transporting path within the Si-rich SiOx film, whose densities are decreased by increasing the substrate
temperature or reducing the induced coupled plasma power. Defect-related white-light electroluminescence emits power for a relatively short lifetime. The lifetime can be lengthened and the electroluminescence power can be raised simultaneously by increasing deposition temperature to 350 °C
and adjusting the induced coupled plasma power to a threshold of 30 W, which effectively increases the densities of Si nanocrystals and nano-pyramids in the Si-rich SiOx film with Si concentration of up to 40 at%. A nearly defect-free Si-rich SiOx sample
can be grown under such conditions, which contributes to the most stable and largest near-infrared electroluminescence with the longest lifetime, although the power–current slope of purely Si nanopyramid related electroluminescence at near-infrared wavelengths is slightly lower.
Application prospect of metal-oxide-semiconductor silicon light emitting devices in integrated circuits
