TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: At least one emitting unit of the compound (B), is a fluorescent emitter unit, preferably phosphorescent emitter unit. The phosphorescent emitter unit and the emitting unit are a metal-ligand-coordination compound. At least one compound is a polymer or dendrimer, and the other compound is a compound exhibiting a molecular weight of less than or equal to 4000 g/mol. The emitting unit is present as a repeating unit either in the main skeleton chain or in the side chain. The side chain is present in a charge transport unit. The charge transport unit is a hole-transport unit or an electron-transport unit. The side chains comprise two charge transport units, where one charge transport unit is the hole-transport unit and the other charge transport unit is the electron transport unit. The main skeleton chain comprises a triplet level with a higher energy, as a triplet level of the phosphorescent emitter unit of the compound (A) and the emitter unit of compound (B). The maximum of the emission band of at least one compound is at a shorter wavelength than the maximum of the emission band of the other compound. The emission band of the compound (A) lies in a wavelength range, overlapping with the wavelength range of the absorption band of compound (B). The maximum of the emission band of the compound (A) lies in the wavelength range of blue light, preferably green light and the maximum of the emission band of compound (B) lies in the wavelength range of green or red light, preferably red light.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The polymer or dendrimer comprises at least one repeating unit from host materials. The compound (A) and/or the compound (B) are a polymer comprising a main skeleton chain. The polymer is a side chain, preferably conjugated or non-conjugated polymer. The compound (A) and the compound (B) are polymer or dendrimer respectively. The unit (A1) is a repeating unit in the main skeleton chain of the polymer and the unit (B1) as a side chain bonded to the main skeleton chain. The unit (A1) and the unit (B1) are repeating units in the main skeleton chain of the polymer. EXAMPLE - No suitable example given.