Schottky-type light emitting devices have been fabricated on Er-oxide doped Si layers grown by molecular beam epitaxy, in order to study the light emission process of Er-doped Si structures. By applying a reverse bias on the Schottky junction, Er ions incorporated within the depletion layer can be electrically excited via a hot electron impact process. Rather intense electroluminescence (EL) at a wavelength of 1.54&mgr;m has been observed at room temperature. The optoelectronic properties of the devices have been characterized by both input-power dependent and temperature dependent EL measurements. An activation energy value of∼160 meV responsible for luminescence thermal quenching has been obtained. ©1997 American Institute of Physics.