New Hole Transporting Materials Based on Tetraphenylbenzene and Aromatic Amine Derivatives for OLEDs

Abstract

Three different new hole transport compounds, namely,2-[1-{4-(N,N-diphenylamino) phenyl}-3,4,5,6-tetraphenylbenzene-2-yl]5-N,N-diphenylaminopyridine(DPAP-TB), 2-[1-{4-(N-phenylnaphthalene-1-amino)phenyl}-3,4,5,6-tetraphenylbenzene-2-yl]5- (N-phenylnaphthalen-1-amino)pyridine(1-PNAP-TB) and 2-[1{4-(N-phenylnaphthal- en-1-amino)phenyl}-3,4-,5,6-tetraphenylbenzene-2-yl]-5-(N-phenylnaphthalen-2-amino)pyridine(2-PNAP-TB) were synthesized. Optical and electronic properties were examined by UV-Visible absorption spectrum and cyclic voltammetry. Luminance efficiencies and external quantum efficiencies of DPAP-TB, 1-PNAP-TB and 2-PNAP-TB were 3.72, 2.82, 3.30 cd/A, and 1.29, 0.97, 1.12% at 10 mA/cm², respectively. Synthesized materials exhibited high T_g in the range of 118 to 133°C. These values are higher than that of NPB which is commonly used as a hole transporting material.

Keywords:

• Hole transporting materials
• organic light-emitting diode

Acknowledgments

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2012001846).

This research was supported by Basic Science Research Program through the NRF funded by the Ministry of Education, Science and Technology (No. 2012-047833).