LIGHT-EMITTING ELEMENT, LIGHT-EMITTING DEVICE, ELECTRONIC DEVICE, AND ILLUMINATING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a light-emitting element of a long life by reducing a particular impurity in a light-emitting element, especially an impurity originating from an iridium complex.SOLUTION: A light-emitting element comprises: an iridium complex. The iridium complex has iridium metal, and a ligand which makes a coordinate bond to the iridium metal. According to liquid chromatography-mass spectrometry on the light-emitting element, the ratio of a peak area of a ligand making no coordinate bond to the iridium metal to a peak area of the iridium complex is 0-10% in a chromatograph by a photodiode array detector.SELECTED DRAWING: Figure 4