Patent ID: 8512880

Claim:
A light-emitting device comprising: a first electrode; a second electrode; and a layer between the first electrode and the second electrode, the layer comprising an organometallic complex comprising a structure represented by a formula (3): wherein R 21 represents an alkyl group having 1 to 4 carbon atoms; each of R 22 to R 25 represents any one of hydrogen, a halogen element, an acyl group, an alkyl group, an alkoxyl group, an aryl group, a cyano group, and a heterocyclic group; Ar represents an aryl group or a heterocyclic group; M represents a Group 9 element or a Group 10 element, in which n=2 when M represents a Group 9 element whereas n=1 when M represents a Group 10 element; and L represents a monoanionic ligand having a beta-diketone structure, a monoanionic bidentate chelate ligand having a carboxyl group, or a monoanionic bidentate chelate ligand having a phenolic hydroxyl group.