MOS-like electroluminescent devices using silicon-rich oxide obtained by LPCVD

Silicon Rich Oxide (SRO) is a multiphase material composed by SiO₂, Si and SiO_x.(0<X<2) SRO characteristics include the photo and cathode emission of visible light. Lastly, big efforts have been devoted to obtain a controllable emission using electroluminescence, but keeping its compatibility with silicon IC´s fabrication technology. In this paper, electroluminescent properties of PolySi/SRO/Si structures were studied. Devices with two different Si excesses were characterized. A full area wideband emission is found on devices with the highest Si excess, the principal emitting bands are centered at 475 and 670 nm. The EL intensity of these bands is modulated by the applied electric field. Different emission colors were observed with the naked eye. The 670 band present in devices with the highest Si excess is not found in those with the lowest Si excess. A discussion on the probable mechanism of emission is presented.