In this paper, we will show our latest results on high-efficiency blue phosphorescent organic light-emitting diodes (PHOLEDs). Effects of triplet exciton confinement, exciton energy transfer and charge trapping, and charge balance on iridium(III)bis[(4,6-di-fluorophenyl)-pyridinato-N,C2'] picolinate (FIrpic)-based blue PHOLEDs will be presented. By optimizing the aforementioned device parameters, a high-efficiency blue PHOLED with 59 cd/A (48 lm/W at 100 cd/m(2)) was demonstrated.