An indium-tin oxide anode was replaced with a p-type silicon anode in a bilayer small-molecule organic light-emitting diode. As results, the current increased largely due to the enhanced hole injection and the higher conductivity of the Si anode; the luminous efficiency decreased significantly due to carrier-induced exciton quenching and the worse charge imbalance. Ultra-thin film Of SiO2 grown on the silicon anode improved the luminous efficiency to a certain extent by restraining the hole injection; enhancing electron injection became more desired. (C) 2004 Elsevier B.V. All rights reserved.