Zinc sulphide phosphor having photo- and electroluminescence, process for its preparation as well as security document, a security feature and method of detection

The present invention relates to a zinc sulfide phosphor and a process for its preparation. In addition, the invention provides a security or value document, a security feature and a method of detection is concerned. The phosphor according to the invention can be excited as electroluminophor by an electric field, whereby electroluminescence in the blue and / or green color range of the light spectrum can be emitted. The phosphor is also excited by UV radiation in the wavelength range between 345 nm and 370 nm, thereby photoluminescence in the blue color range of the light spectrum from the phosphor can be emitted. The phosphor further excited by UV radiation in the wavelength range between 310 nm and 335 nm, thereby photoluminescence in the green color range of the light spectrum from the phosphor can be emitted.