LUMINESCENT MATERIAL, LIGHT-EMITTING ELEMENT, OXYGEN SENSOR, LIGHT-EMITTING DEVICE, ELECTRONIC INSTRUMENT AND LIGHTING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a luminescent material having high emission efficiency, or a light-emitting element having high emission efficiency.SOLUTION: A luminescent material is expressed by the formula IrLX, and has ≤5% proportion of the spin distributed in the X in the most stable structure at the lowest triplet excited state. In the formula, Ir is iridium; L is a ligand having a structure in which at least an sphybrid carbon atom binds with the Ir; and X is a monoanionic bidentate ligand obtained by coordinating two nitrogen atoms, a nitrogen atom and an oxygen atom, or two oxygen atoms to the Ir.