A Bipolar and Small Singlet-Triplet Splitting Energy Host with Triplet Energy Lower Than a Blue Phosphor for Phosphorescent OLEDs in Panchromatic Range

查看全文 作　　者：Chuanjun [1]Wang;Gaowen [1]Liu;Shaojie [1]Liu;Xunlu [1]Zhang;Changjin [2]Ou;Lu [2]Wang;Wei [1]Sun;Baoxiu [1]Mi;Juan [1]Song;Zhiqiang [1]Gao 机构地区：[1]Key Laboratory for Organic Electronics & Information Displays (KLOEID), Jiangsu Engineering Centre for Plate Displays & Solid State Lighting, and Institute of Advanced Materials (IAM), School of Material Science and Engineering, Nanjing University of Posts & Telecommunications, Nanjing, Jiangsu 210023, China;[2]Key Laboratory of Flexible Electronics & Institute of Advanced Materials, Jiangsu National Synergetic Innovation Center for Advanced Materials ( SICA M), Nanjing Tech University, Nanjing, Jiangsu 211816, China 出　　处：《Chinese Journal of Chemistry》索引2016年第34卷第8期,共8页 摘　　要：A bipolar host material, 2,4,6-tris(3-(carbazol-9-yl)phenyl)-triazine (TCPZ), was synthesized according to re-ported method. Due to the higher triplet energy compared to green and red phosphors, TCPZ is suitable to host themin phosphorescent organic light-emitting diodes (PhOLEDs). Although the triplet of TCPZ is slightly lower than acommon blue phosphor, good blue PhOLEDs using TCPZ as the host were successfully demonstrated in this work.By low temperature emission measurement, it was found that the energy splitting between the singlet and triplet ofTCPZ is as small as 0.24 eV. Therefore, thermal activated energy transfer from triplet to singlet in the host TCPZ isexpected to occur, which can be afterwards efficiently transferred to the blue phosphor, hence enabling it to hostblue phosphor. As a result, TCPZ can be used as host for phosphors in panchromatic range. Additionally, sin-gle-carrier devices clearly prove its good bipolar transport feature, beneficial to device performance. By usingTCPZ as a host, high performance deep-red, green and blue PhOLEDs have been achieved, with maximum effi-ciencies of 9.3 cdoA 1 (13.2%), 81.3 cd·A 1 (23.1%) and 17.03 cd·A^-1 (10.4%), respectively. 关 键 词：panchromatic, HOST material, bipolar, SMALL singlet-triplet splitting, large emission overlap