Crosslinkable Fluorene-Based Derivatives as Materials for Light Emitting Diodes

Abstract

A series of cross-linkable fluorene-based derivatives have been synthesized by the multistep synthetic rout. Characterization of their structure by ¹H NMR and mass spectrometry is presented. The synthesized materials were examined by various techniques including differential scanning calorimetry, thermogravimetry, UV, fluorescence and electron photoemission spectrometries. It is established that the new derivatives have large triplet energies and could be used as host materials in phosphorescent light emitting diodes. The device fabricated with the use of one of the new hosts reached a brightness of 1700 cd/m² and a current efficiency of 3.4 cd/A.

Keywords:

• aromatic amine
• cross-linkable material
• ionization potential
• light emitting diode
• triplet energy

Acknowledgments

Financial support of this research by the Lithuanian Science and Studies Foundation and by the Alexander von Humboldt Foundation (Germany) is gratefully acknowledged.