| 초록 |
The blue TADF device has a low stability of the molecule and lifetime due to the TTA process which generates high energy. One of the ways to solve the above problem is to increase the stability of the molecule by strengthening the C-N bond by introducing an electron withdrawing unit into the molecule. In this study, In order to increase the bond dissociation energy, 3,3"-di(9H-carbazol-9-yl)-[1,1':2',1"-terphenyl]-3'-carbonitrile(oCN-oTP) and 3,3"-di(9H-carbozol-9-yl)-[1,1':2',1"-terphenyl]-3'-carbonirile(mCN-oTP) in which the cyano group was substituted with ortho and meta positions in the DCz-oTP with high triplet energy were synthesized and evaluated. When the TADF device were evaluated for DCz-oTP, oCN-oTP, mCN-oTP, the the maximum EQE of 24.6, 29.5, 21.9% was achieved, showing high efficiency. Moreover, It was confirmed that oCN-oTP and mCN-oTP increased their lifetime by 1820% and 500%, respectively, compared to DCz-oTP. |
