Intramolecular energy transfer in heteroleptic red phosphorescent dopants

Abstract

Intramolecular energy transfer in heteroleptic red phosphorescent dopant materials with mixed ligand units in one molecule was studied. 1-phenylisoquinoline (piq) and phenylpyridine (ppy) moieties were introduced as ligands for Ir based phosphorescent dopants and light emission mechanism was investigated. Intramolecular energy transfer from ppy ligand to piq ligand resulted in pure red emission without any green emission from ppy. Current efficiency of red devices was improved from 4 to 4.8 cdA by using mixed ligand structures. © 2006 American Institute of Physics.