A stable red organic light-emitting device has been realized by doping a red dye tetra-methyljuloidine(DCJT)in electron transporting layer(ETL).The structure of the device was ITO/ CuPc/ NPB/ Alq: DCJT/ MgAg
where copper phthalocyanine(CuPc)was used as a buffer layer
N
N ’-his-(1-napthyl)-N
N’-diphenyl-1
1’-biphenyl-4
4’-diamine(NPB)as the hole transporting layer
tris(8-quinolinolato)aluminum complex(Alq)as ETL
in which DCJT was doped
indium tin oxide(ITO)and MgAg were as the anode and cathode
respectively.The red emission with peak at 620nm and CIE coordinates
x
=0.63
y
=0.37
maximum luminance 4687cd/m
2
maximum luminous efficency 0.83lm/W were obtained.The device showed a high stability under 12mA/cm
2
current density continuous operation
the half decay time reached 2 500 hours at the initial luminance 150cd/m
2
and the change of driving voltage was 0.6mV/hour in the degradation process.If 50cd/m
2
is taken as the initial luminance of red device
the half decay time is considered to be 7500 hours.(According to European Broadcasting Union(EBU)standard
for color display the ratios for red
green
blue luminance should be 30%
59% and 11%
respectively
since 100cd/m
2
is often used as initial luminance of green emission in degradation test
50cd/m
2
should be adapted as the initial luminance for red emission.)