基于有机异质结C60/ZnPc的绿色磷光TOLED

Green Phosphorescent Tandem Organic Light-emitting Diodes Based on Organic Heterojunction of C60/ZnPc

以有机异质结C60/ZnPc作为电荷产生层,制备结构为ITO/TPBi(40nm)/C60(x nm)/ZnPc(x nm)/NPB(40nm)/Al(120nm)和ITO/TPBi(40nm)/LiF(y nm)/Al(2nm)/C60(5nm)/ZnPc(5nm)/MoO3(3nm)/NPB(40nm)/Al(120nm)的非发光倒置器件,其中x的值为0、5、10和15,y的值为0、0.5、1.0和1.5.实验证明,有机异质结C60/ZnPc可在外电场下实现电荷分离,加入LiF/Al和MoO3可更有效地提高电荷产生层的电荷分离和注入能力.基于LiF/Al/C60/ZnPc/MoO3结构,制备绿色磷光叠层有机发光二极管,进一步研究该电荷产生层对叠层器件的光电性能影响.结果表明,电荷产生层的电荷分离和注入可影响叠层器件内部的电荷注入平衡,进而对器件性能产生影响.当LiF、Al、C60、ZnPc和MoO3结构厚度分别为0.5nm、1nm、5nm、5nm和3nm时,电荷产生层产生的电荷与两侧电极注入的电荷达到匹配,使叠层器件具有最佳光电性能,获得了高效绿色磷光叠层器件,其驱动电压明显低于单层器件2倍,最大亮度、电流效率和功率效率分别达84660cd·m^-2、94.7cd·A^-1和43lm·W^-1.

Two inverted non-lighting devices with the configurations of ITO/TPBi(40 nm)/C 60 (x nm)/ZnPc(x nm)/NPB(40 nm)/Al(120 nm)(x=0,5,10,and 15) and ITO/TPBi(40 nm)/LiF(y nm)/Al(2 nm)/C 60 (5 nm)/ZnPc(5 nm)/MoO 3 (3 nm)/NPB(40 nm)/Al(120 nm)(y=0,0.5,1.0,and 1.5) were fabricated.The experiments illustrate that the organic heterojunction of C 60 /ZnPc can realize charge separation under external field and demonstrate that ability of charge separation and injection can be efficiently improved by the electron injection layer of LiF/Al and hole injection layer of MoO 3.C 60 /ZnPc was used as charge generation layer (CGL),LiF/Al and MoO 3 were employed as charge injection layers.Moreover,a series of green phosphorescent Tandem Organic Light-Emitting Diodes (TOLEDs) based on the multilayer structure of LiF/Al/C 60 /ZnPc/MoO 3 was also fabricated to further explore the effect of the CGL on photoelectronic performances for tandem devices.Experimental results show that the performance of tandem devices can be influenced by the effect of charge separation and injection of CGL on charge-injection balance inside TOLEDs.When the multilayer structure is LiF(0.5 nm)/Al(1 nm)/C 60 (5 nm)/ZnPc(5 nm)/MoO 3 (3 nm),a green TOLED with a better charge balance and an optimal device performance is achieved,the operating voltage of the tandem device is below two-fold of correspording single OLED.The peak luminance,peak current efficiency,and peak power efficiency for the green TOLED reach 84 660 cd·m^-2 ,94.7 cd·A^-1 and 43 lm·W^-1 ,respectively.