In order to use organic light emitting devices (OLEDs) in display application , it is very important to obtain red emitting light. There are two methods for obtaining red emitting light: doping high fluorescent dyes i...In order to use organic light emitting devices (OLEDs) in display application , it is very important to obtain red emitting light. There are two methods for obtaining red emitting light: doping high fluorescent dyes in host or using metal complexes. Phosphorescent dyes has been used efficiently recently. In this letter, we demonstrate red organic light emitting devices (OLED) with the electroluminescent layers consisting of aluminum tris(8 hydroxyquinoline) (Alq 3) doped with the dye DCM and DCJTB, which the emission color depends on the concentration of DCM and DCJTB. The typical cell structure is as follows: [ITO/ hole transport layer (60nm, TPD) /emitting layer(60nm, Alq 3 + red dopant) /LiF(0.5～2nm) /Al(150nm)]. For DCM doped devices, the maximum luminance of 148000cd/m 2 (chromaticity coordinates: x =0.51, y =0.47) and 5730cd/m 2 (chromaticity coordinates: x =0.58, y =0.42) are measured for DCM concentration of 0.2% and 2% in Alq 3, respectively; and for DCJTB doped devices, 17400 cd/m 2 (chromaticity coordinates : x =0.51, y =0.46) and 3846cd/m 2 (chromaticity coordinates: x =0. 63, y =0. 37) are obtained for DCJTB concentration of 0. 2 % and 2% in Alq 3, respectively.展开更多
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 ...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 4 687cd/m2, maximum luminous efficency 0. 83lm/W were obtained. The device showed a high stability under 12mA/cm2 current density continuous operation, the half decay time reached 2 500 hours at the initial luminance 150cd/m2 and the change of driving voltage was 0. 6mV/hour in the degradation process. If 50cd/m2 is taken as the initial luminance of red device, the half decay time is considered to be 7 500 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/m2 is often used as initial luminance of green emission in degradation test, 50cd/m2 should be adapted as the initial luminance for red emission. )展开更多
文摘In order to use organic light emitting devices (OLEDs) in display application , it is very important to obtain red emitting light. There are two methods for obtaining red emitting light: doping high fluorescent dyes in host or using metal complexes. Phosphorescent dyes has been used efficiently recently. In this letter, we demonstrate red organic light emitting devices (OLED) with the electroluminescent layers consisting of aluminum tris(8 hydroxyquinoline) (Alq 3) doped with the dye DCM and DCJTB, which the emission color depends on the concentration of DCM and DCJTB. The typical cell structure is as follows: [ITO/ hole transport layer (60nm, TPD) /emitting layer(60nm, Alq 3 + red dopant) /LiF(0.5～2nm) /Al(150nm)]. For DCM doped devices, the maximum luminance of 148000cd/m 2 (chromaticity coordinates: x =0.51, y =0.47) and 5730cd/m 2 (chromaticity coordinates: x =0.58, y =0.42) are measured for DCM concentration of 0.2% and 2% in Alq 3, respectively; and for DCJTB doped devices, 17400 cd/m 2 (chromaticity coordinates : x =0.51, y =0.46) and 3846cd/m 2 (chromaticity coordinates: x =0. 63, y =0. 37) are obtained for DCJTB concentration of 0. 2 % and 2% in Alq 3, respectively.
文摘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 4 687cd/m2, maximum luminous efficency 0. 83lm/W were obtained. The device showed a high stability under 12mA/cm2 current density continuous operation, the half decay time reached 2 500 hours at the initial luminance 150cd/m2 and the change of driving voltage was 0. 6mV/hour in the degradation process. If 50cd/m2 is taken as the initial luminance of red device, the half decay time is considered to be 7 500 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/m2 is often used as initial luminance of green emission in degradation test, 50cd/m2 should be adapted as the initial luminance for red emission. )
