US 9,670,406 B2 · Zinc sulphide phosphor having photo- and electroluminescent properties, process for producing same, and security document, security feature and method for detecting same

Abstract

The present invention relates to a zinc sulphide phosphor and to a process for producing same. The invention further relates to a security document or document of value, to a security feature and to a method for detecting same. The phosphor according to the invention can act as electroluminescent phosphor and thus be excited by an electrical field, and this can result in emission of electroluminescent light in the blue and/or green color region of the visible spectrum. The phosphor can moreover be excited by UV radiation in the wavelength range than 345 nm to 370 nm, and can thus emit photoluminescent light in the blue color region of the visible spectrum. The phosphor can moreover be excited by UV radiation in the wavelength range from 310 nm in 335 nm, and can thus emit photoluminescent light in the green color region of the visible spectrum.

Claims14

Dependent claims

A zinc sulfide phosphor, which, in the case of excitation by an electric field, emits in the blue and/or green region of the light spectrum, in the case of excitation by UV radiation in the wavelength range between 345 nm and 370 nm, emits in the blue region of the light spectrum, and, in the case of excitation by UV radiation in the wavelength range between 310 nm and 335 nm, emits in the green region of the light spectrum;

wherein the emission in the case of excitation by UV radiation in the wavelength range between 345 nm and 370 nm differs from the emission in the case of excitation by UV radiation in the wavelength range between 310 nm and 335 nm;
and wherein the phosphor has the following general chemical formula:
ZnS:Aa, Mb, Xc where:
A=Cu, where Cu can be replaced proportionally by Ag and/or Au;
M=Al, where Al can be replaced proportionally by Bi, Ga and/or In;
X=one or more halides, selected from the group comprising the elements F, Cl, Br and I;
0<(a+b+c)<0.12;
0.0001<a<0.008;
0.6·a<b<4·a, and
2·b<c<4·b.

7 more elements

Dependencies are inferred from the claim text.

Zinc sulphide phosphor having photo- and electroluminescent properties, process for producing same, and security document, security feature and method for detecting same

Life of this patent

Zinc sulphide phosphor having photo- and electroluminescent properties, process for producing same, and security document, security feature and method for detecting same

Life of this patent

Abstract

Claims14