Holmiumdotierte anti-Stokes phosphors and security features with these phosphors

The invention relates to a phosphor, particularly for use in security documents, comprising a host lattice of rare earth oxysulfide, which is doped with at least two ionic species, wherein the fluorescent anti-Stokes luminescence and luminescence according to Stokes' rule indicates when irradiated with an excitation radiation becomes. According to the invention the phosphor contains two fluorescent components which are co-doped with one hand, ytterbium / holmium, and the other hand with ytterbium / erbium. Preferably, the phosphor for the formation of security features may be used.