We have developed top emission organic light-emitting devices using a CsCl capping layer on top of semitransparent Ca/Ag cathode. By using a CsCl capping layer, the transmittance of top electrode can be improved by 93%. While the electrical conduction characteristic of device is not influenced by the capping layer, the current efficiency increases with increasing the transmittance of Ca/Ag/CsCl cathode. For example, as the transmittance of top electrode increases from 55 to 91% by varying CsCl thickness, the current efficiency of green fluorescent top-emitting device increases from 8 to 18 cd/A. (C) 2009 Elsevier B.V. All rights reserved.