Synthesis and Properties of New Imidazole Derivatives Including Various Chromophore for OLEDs

Abstract

Two new blue compounds were successfully synthesized by introducing phenanthroimidazole group as a side group into pyrene, a chromophore with good luminous efficiency: 1-(4-(10-(naphthalen-2-yl)anthracen-9-yl)phenyl)-2-(pyren-1-yl)-1H-phenanthro[9,10-d]imidazole (NA-PPI) and 1-(4'-(9H-carbazol-9-yl)-[1,1'-biphenyl]-4-yl)-2-(pyren-1-yl)-1H-phenanthro[9,10-d]imidazole (CP-PPI). The optical and electroluminescence properties of newly synthesized materials were measured. Both materials emit blue or sky-blue photoluminescence in the film state and have a high PLQY value of over 80% in solution state. The synthesized materials were applied as EML in non-doped devices, and high efficiency of 3.51 cd/A and EQE of 2.39% in CP-PPI device were achieved.

Keywords:

• Organic light-emitting diode
• blue emission
• fluorescence
• pyrene
• imidazole

Acknowledgment

This research was supported by National R&D Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science & ICT (No. 2017M3A7B4041699), the Fundamental R&D Program for Core Technology of Materials funded by the Ministry of Trade, Industry and Energy, Republic of Korea (Project No. 10080565) and Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education (No. 2017R1D1A1A09082138).