Abstract
Visible electroluminescence (EL) has been observed from Ag (film or paste)/native SiO2/n -type Si structures. The diodes show good rectification behavior and the EL occurs only under reverse bias conditions when the top Ag electrode is negative. For p-type samples, a forward bias is required. The intensity of the EL is proportional to the diode current and its spectrum peaks at 620–640 nm. A model based on oxygen-related luminescent centers in the native oxide is proposed.