Patent ID: 7416791

Claim:
A composition, comprising an osmium complex having the formula: [Os(II)(N—N) 2 L—L] 2+ , 2A − or A 2− wherein Os(II) comprises divalent osmium; N—N comprises a 2,2′-bipyridine ligand substituted with aryl, arylalkyl, alkenyl, alkoxy, amino, alkylamino, dialkylamino, or halogen, or a substituted or unsubstituted 1,10-phenanthroline ligand; L—L comprises a π-acid bidentate ligand; and A comprises a counter ion; and a host material, the host material having an emission spectrum and the osmium complex having an absorbance spectrum, wherein the host material emission spectrum and the osmium complex absorbance spectrum have a spectral overlap sufficient to effect energy transfer from the host material to the osmium complex.