A solution-processible phosphorescent dendrimer, which has a fac-tris(2-phenylpyridyl)iridium(III) complex at its core and is encapsulated by six first-generation dendrons (see Figure), eliminates luminescence quenching in the solid state. The dendrimer can be used as a host-free light-emitting layer to give highly efficient bilayer dendrimer light-emitting diodes.