Acta Photonica Sinica, Volume. 48, Issue 7, 723003(2019)
Green Phosphorescent Tandem Organic Light-emitting Diodes Based on Organic Heterojunction of C60/ZnPc
Two inverted non-lighting devices with the configurations of ITO/TPBi(40 nm)/C60(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)/C60(5 nm)/ZnPc(5 nm)/MoO3(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 C60/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 MoO3. C60/ZnPc was used as charge generation layer (CGL), LiF/Al and MoO3 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/C60/ZnPc/MoO3 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)/C60(5 nm)/ZnPc(5 nm)/MoO3(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,
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CHEN Ai, WANG Zhen, XIE Jia-feng, WANG Pei, XIAO Fei, CHEN Jia-wen, LU Yong-sheng, ZHANG Wen-xia, WANG Yu-chan. Green Phosphorescent Tandem Organic Light-emitting Diodes Based on Organic Heterojunction of C60/ZnPc[J]. Acta Photonica Sinica, 2019, 48(7): 723003
Received: Jan. 17, 2019
Accepted: --
Published Online: Jul. 31, 2019
The Author Email: Ai CHEN (1015315076@qq.com)