The band-edge electroluminescence at room temperature from metal-oxide-silicon tunneling diodes on (110) substrates was observed. Both the transverse acoustic and the transverse optical phonon lines are necessary to fit emission spectra. A comprehensive picture composed of localized holes, phonons and interface roughness is given to describe the radiation process. The picture can be used to explain the enhanced electroluminescence intensity, as compared to photoluminescence, and can be used to understand the substrate orientation effect on electroluminescence intensity. (C) 2002 Elsevier Science Ltd. All rights reserved.