White organic light emitting diodes 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(Device l) and ITO/CuPc/NPB/JBEM(P)/Alq:DCJT/Alq/MgAg(Device 2).Here copper phthalocyanine(CuPc)is the buffer layer;N

N’-bis-(1-naphthyl)-N

N’-diphenyl-1.1’-bipheny 1-4-4’-Ddiamine(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)aluminium 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 14.850cd/m

2

an efficiency of 2.88 lm/W

Commission Internationale de I’Eclairage(CIE)coordinates

x

=0.32

y

=0.38 (from 4mA/cm

2

to 200mA/cm

2

)

and the half lifetime 2 860 hours at the starting luminance of 100cd/m 2.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.