Enhanced 1.54-μm photo- and electroluminescence based on a perfluorinated Er(III) complex utilizing an iridium(III) complex as a sensitizer.

Abstract

Advanced 1.5-µm emitting materials that can be used to fabricate electrically driven light-emitting devices have the potential for developing cost-effective light sources for integrated silicon photonics. Sensitized erbium (Er3+) in organic materials can give bright 1.5-µm luminescence and provide a route for realizing 1.5-µm organic light emitting diodes (OLEDs). However, the Er3+ electroluminescence (EL) intensity needs to be further improved for device applications. Herein, an efficient 1.5-µm OLED made from a sensitized organic Er3+ co-doped system is realized, where a "traditional" organic phosphorescent molecule with minimal triplet-triplet annihilation is used as a chromophore sensitizer. The chromophore provides efficient sensitization to a co-doped organic Er3+ complex with a perfluorinated-ligand shell. The large volume can protect the Er3+ 1.5-µm luminescence from vibrational quenching. The average lifetime of the sensitized Er3+ 1.5-µm luminescence reaches ~0.86 ms, with a lifetime component of 2.65 ms, which is by far the longest Er3+ lifetime in a hydrogen-abundant organic environment and can even compete with that obtained in the fully fluorinated organic Er3+ system. The optimal sensitization enhances the Er3+ luminescence by a factor of 1600 even with a high concentration of the phosphorescent molecule, and bright 1.5-µm OLEDs are obtained.