Synthesis of carbazole-based dendrimer: host material for highly efficient solution-processed blue organic electrophosphorescent diodes

详细信息    查看全文

• 作者：Wei Jiang^a ; Jinan Tang^a ; Wen Yang^a ; Xinxin Ban^a ; Bin Huang^a ; Yunqian Dai^a ; Yueming Sun^a ; ^{101011462@seu.edu.cn} ; Lian Duan^b ; ^{duanl@tsinghua.edu.cn} ; Juan Qiao^b ; Liduo Wang^b ; Yong Qiu^b
• 关键词：OLEDs ; Solution-processed ; Electrophosphorescence ; Dendrimer
• 刊名：Tetrahedron
• 出版年：2012
• 出版时间：22 July, 2012
• 年：2012
• 卷：68
• 期：29
• 页码：5800-5805
• 全文大小：856 K

文摘

This paper reports the synthesis and physical properties of two novel carbazole-based dendritic host materials Cz-CCP and Cz-mCP for solution-processed blue phosphorescent organic light-emitting devices (PhOLEDs). These dendritic hosts exhibit high triplet energy (?.85?eV), excellent film-forming ability (with low root-mean-square (rms) values less than 0.2?nm), high glass-transition temperatures in the range of 242-248?¡ãC, and the appropriate HOMO energy levels (?.33-?.35?eV) facilitating the transfer of holes from Poly(3,4-ethylenedioxythiophene):Poly(styrene-4-sulfonate) (PEDOT:PSS) to the emitting layer. The single-layer device using Cz-CCP and Cz-mCP as the host for the phosphorescence emitter iridium(III) bis(4,6-difluorophenylpyridinato)-picolinate (FIrpic) showed the maximum luminance efficiencies of 9.6 and 10.8?cd?A^?, respectively. By introducing a thin 1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBI) electron-transporting and exciton-confining layer, the maximum efficiency of the solution-processed double-layer device based on Cz-CCP and Cz-mCP can be further improved to 20.5 and 22.7?cd?A^?, and maximum external quantum efficiencies as high as 10.2 % and 11.5 % , respectively. These results demonstrated that the newly synthesized, carbazole-based dendritic host materials are advantageous for fabrication of highly efficient blue PhOLEDs.