High efficiency, blue emitting materials based on phenanthro [9,10-d]imidazole derivatives

The blue light emitting materials based on a fluoro phenanthro [9,10-d] imidazole derivatives prepared by a facial synthetic process exhibit good thermal stability, highly efficient fluorescence and balanced carrier injection. The multi-layered device based on fluoro phenanthroimidazole derivatives shows a higher luminance in a lower turn-on voltage. The device performance implies that the phenanthroimidazole unit is an excellent building block for tuning the carrier injection properties as well as blue emission. (C) 2014 Elsevier B.V. All rights reserved.