Electroluminescence in Si/SiO2 layer structures

Electroluminescence spectra have been studied on samples consisting of a single SiO2 or poly Si layer or SiO2/Si layer pair grown either on silicon or metal substrates. The samples were designed for determining the conditions and the location where electroluminescence originates in SiO2/Si structures. An intermediate gold layer was used to isolate the active layers from the silicon substrate. The results indicate that significant electroluminescence emission can be observed only in those samples that have SiO2 p-type crystalline Si interface. The most promising explanation of this phenomenon is that there are defect levels in the thin silicon oxide layer near the interface.