Organic light-emitting diodes (OLEDs) have become a viable technology for flat panel display after intensive research and progress since the first demonstration of the double-layer device in 1987.Through proper material design and device fabrication, diversiform colors with high brightness and good stability have been developed for single-or full-color applications.Among the various colors, particular attention has been paid to the blue OLEDs due to their deficiency of electroluminescent performance.