Enhanced hole injection in a bilayer vacuum-deposited organic light-emitting device using a p-type doped silicon anode

Abstract

We report the fabrication of a vacuum-deposited light-emitting device which emits light from its top surface through an Al cathode using p-type dopedsilicon as the anodematerial. Enhanced hole injection is clearly demonstrated from the p- Si anode as compared to the indium–tin–oxide (ITO) anode. The mechanisms of hole injection from both the p- Si and ITO anodes into the organic layer are investigated and a possible model based on anode surface band bending is proposed. During the operation of the organic light-emitting device, the surface band bending of the anode plays a very important role in modifying the interfacial barrier height between the anode and the organic layer.