The authors have demonstrated hybrid white organic light-emitting diodes (HWOLEDs) on electroluminescent characteristics for codoped spacer ratio effect using N,N'-dicarbazolyl-3,5-benzene (mCP) and 4,7-dipheny1-1,10-phenanthroline (BPhen). The optimized HWOLEDs of spacer ratio (3:1) which had proper recombination balance of holes and electrons, mCP:BPhen, showed the external quantum efficiency of 6.01%, the power efficiency of 8.12 lm/W, and Commission Internationale de l'Eclairage coordinates of (0.37, 0.41) at 1000 cd/m(2). (C) 2010 Elsevier B.V. All rights reserved.