The effectiveness of Cs-derivatives, including cesium carbonate (Cs(2)CO(3)), cesium fluoride (CsF), and cesium nitrite (CsNO(3)), as dopants of tris-(8-Hydroxyquinoline)-aluminum (Alq(3)) in organic light-emitting diodes (OLEDs) were investigated via photoemission spectroscopy and current-voltage characteristics. The n-type doping of Cs(2)CO(3) in Alq(3) is most effective. In current injection efficiency, the performance of OLEDs with CsF in cathode structures is similar to that with Cs(2)CO(3), working well with both aluminum and silver in cathodes. As for CsNO(3), it is effective only with aluminum cathode due to the reaction between aluminum and CsNO(3). (C) 2010 Elsevier B.V. All rights reserved.