This light emitting device includes a pair of electrodes at least one of which is transparent or translucent, and a phosphor layer that is sandwiched between the electrodes and has a polycrystalline structure made of a first semiconductor material, and in this structure, a second semiconductor material different from the first semiconductor material is segregated on a grain boundary of the polycrystalline structure. The first semiconductor material and the second semiconductor material preferably have semiconductor structures of conduction types that are different from each other. Moreover, the first semiconductor material preferably has an n-type semiconductor structure, and the second semiconductor material preferably has a p-type semiconductor structure. Furthermore, in the case where the first semiconductor material is a zinc-based material containing zinc, at least one of the paired electrodes is preferably made of a material containing zinc.