The invention provides an OLED device containing certain alkali metal cluster compounds with mixed ligands, such compounds, and methods of making them. In particular, the cluster compound is a neutrally charged mixed cluster compound comprising first and second subunits with the first subunit comprising an alkali metal salt of a nitrogen containing a heterocyclic ligand bearing a anionic hydroxy group and the second subunit consisting of an organic alkali metal salt different than the first subunit.