Infrared organic light emitting diodes using neodymium tris-(8-hydroxyquinoline)

We have studied the photoluminescence and electroluminescence of neodymium tris-(8-hydroxyquinoline) and have found evidence, from the Stark splitting of the neodymium emission, for two isomers of the molecule. Following sublimation it appears that one of these isomers predominates. Photoluminescence can be excited through absorption into the organic ligands and there appears to be efficient coupling between the singlet and triplet exciton levels in the ligand and the internal levels of the neodymium. We can obtain bright infrared electroluminescence from the intraatomic levels within the neodymium at wavelengths of 900, 1064, and 1337 nm. (C) 2000 American Institute of Physics. [S0021-8979(00)00714-3].