High power efficiency blue organic light-emitting diode (OLED), based on 2-methyl-9,10-di(2-naphthyl) anthracene (MADN) and p-bis(p-N,N-diphenyl-amino-styryl) benzene (DSA-ph), has been realized by combining heterojunction (HJ) structure and mixed host (MH) structure in one device. This combination resulted in both high current efficiency and low driving voltage, and thus highly efficient blue OLED with peak power efficiency of 5.0 lm/W was achieved, which is approximately five times higher than 1.1 lm/W in the MH control device and 56% higher than 3.2 lm/W in the HJ control device. (C) 2011 Elsevier B.V. All rights reserved.