Stable and current independent white-emitting organic diode

White organic light emitting diodes (OLEDs) with new blue material and two kinds of structures have been constructed: one with blue and red emission in a same layer, the other with blue and red emission in separated layers. The configurations of the devices are ITO/CuPc/NPB/JBEM(P):DCJT/Alq/MgAg (Device1) and ITO/CuPc/NPB/JBEM(P)/Alq:DCJT/Alq/MgAg (Device2). Here, copper phthalocyanine (CuPc) is the buffer layer; N,N′-bis(1-naphthyl)-N,N′-diphenyl-1.1′-bipheny1-4-4′-diamine (NPB) is the hole transporting layer (HTL); 9,10-bis(3′5′-diaryl)phenyl anthracene doped with perylene (JBEM(P)) is a new blue emitting material; tris(8-quinolinolato)aluminum complex (Alq) is the electron transporting layer (ETL), and DCJT is a red dye. A stable and current independent white OLED has been obtained in the device with blue and red emission in the same layer. It shows a maximum luminance of 14 850 cd/m2, an efficiency of 2.88 Lm/W, Commission Internationale de I’Eclairage (CIE) co-ordinates x=0.32, y=0.38 from 4 to 200 mA/cm2, and the half lifetime 2860 h at the starting luminance of 100 cd/m2. It is proved that the device with blue and red in the same layer has better characteristics than the device with blue and red in separated layers in luminance, efficiency and stability.