Novel ambipolar orthogonal donor-acceptor host for blue organic light emitting diodes
Man-kit Leung1, Yu-Hsuan Hsieh, Ting-Yi Kuo
1Department of Chemistry, Institute of Polymer Science and Engineering, Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University , 1 Roosevelt Road Section 4, Taipei 106, Taiwan, R.O.C., and Department of Photonics Engineering, Yuan Ze University , 135 Yuan-Tung Road, Chung-Li 32003, Taiwan, R.O.C.
Abstract:
Ambipolar triplet hosts comprising 1,2,4-triazole and carbazole in ortho-positions have been developed. The blue PHOLED has a high current efficiency of 47.1 cd A(-1), power efficiency of 41.2 lm W(-1), and low efficiency roll-off. The high efficiency was attributed to the successful control of π-conjugation through orthogonal arrangement of the substituents so that a wide T1-S0 gap could be maintained.


